Hedera crebrescens (Araliaceae) a newly identifi ed diploid taxon and triploid ivies from Hungary

Abstract

Hedera crebrescens, a newly identified species in Hungary is described here. This diploid ivy is not identical with the diploid H. helix. It grows vigorously, is invasive, and has spread into most parts of the country and adjacent regions. We also present two triploid species of hybrid origin, which were known formerly as selected varieties of H. helix. Triploids differ from the presumed diploid and tetraploid parents based on their reproductive morphological traits and also based on their ecological demands.

Full text

Studia botanica hungarica 48(2), 2017
Hungarian Natural History Museum, Budapest
Studia bot. hung. 48(2), pp. 225–252, 2017
DOI: 10.17110/StudBot.2017.48.2.225
HEDERA CREBRESCENS ARALIACEAE
A NEWLY IDENTIFIED DIPLOID TAXON AND
TRIPLOID IVIES FROM HUNGARY
Márta B-H1, Endre György T1, Szabina L2,
István P3, György Dénes B4 and Mária H1*
1Szent István University, Faculty of Horticultural Science, Department of Botany and Soroksár
Botanical Garden, Budapest, Hungary, *hohn.maria@kertk.szie.hu
2Eszterházy Károly University, Eger, Hungary
3Eötvös Lóránd University, Department of Genetics, Budapest, Hungary
4Szent István University, Department of Viticulture, Budapest, Hungary
Bényei-Himmer, M., Tóth, E. Gy., Lengyel, Sz., Pintér, I., Bisztray, Gy. D. & Höhn, M. (2017):
Hedera crebrescens (Araliaceae) a newly identi ed diploid taxon and triploid ivies from Hungary.
– Studia bot. hung. 48(2): 225–252.
Abstract: Hedera crebrescens, a newly identi ed species in Hungary is described here.  is diploid
ivy is not identical with the diploid H. helix. It grows vigorously, is invasive, and has spread into
most parts of the country and adjacent regions. We also present two triploid species of hybrid ori-
gin, which were known formerly as selected varieties of H. helix. Triploids di er from the presumed
diploid and tetraploid parents based on their reproductive morphological traits and also based on
their ecological demands.
Key words: Hedera crebrescens, invasive, new species, nomenclature, triploids
INTRODUCTION
Hedera is the only genus of the woody Araliaceae family native to Europe. It
occurs along the northern hemisphere including Europe, the Macaronesian islands,
Northwest Africa, and East Asia (L 1930). P (1974) mentioned
14 species, R et al. (1993) listed 12 species and later (MA   and
R 1997) 11, while V and V (2010) recognized 13 spe-
cies.  e most recently published European Garden Flora reports 12 Hedera taxa
(MA and M 2017: 141). In Hungary and East Central Europe
only Hedera helix (L 1753) is considered native (S and J 1951,
S 1966). It is widespread in most parts of the country but it is less frequent in
the Great Hungarian Plain with the exception of an area in the southeastern part
(B-H 1994: 12; B and K 2015: 65).
At the end of the nineteenth century, a lot of Hedera cultivars were planted
in European gardens (R 1996). Most of the cultivated ivies were mentioned as

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
226
Studia bot. hung. 48(2), 2017
“Hedera hibernica”, “Hedera helix hybernica” or “hibernica hort” (S
1875).  ey originated primarily in the British Isles as Scottish, Irish, or English
ivies. In France and Belgium cultivated ivies were also referred to as “H. hiberni-
ca” and this obviously made it di cult later to distinguish this taxon de nitively
(K 1869). Moreover, much confusion has been caused by attributing this
name to the planted materials from nurseries. H. hibernica (G. Kirchn.) Bean is
considered a western European taxon and, in contrast to H. helix, is tetraploid
(J 1954).
In the last decades several morphological (A and W 2002,
2003, K et al. 2003, S 2004, V and V 2010) and
molecular studies (V et al. 1999, G and P 2002, G et al.
2011) were performed on Hedera taxa with the aim of revealing phylogenetic
relationships and evolution. However, molecular studies followed by cytometric
measurements revealed that polyploidy was the major phenomena in the evo-
lution of Hedera species, and might have taken place several times independ-
ently in di erent lineages (G et al. 2011). Geographical groups of taxa can
include di erent ploidy levels, diploids, and polyploids.  ese studies also re-
vealed that formerly used morphological traits such as trichome morphology
are not considered evolutionarily stable in ivies (G et al. 2011, V et
al. 1999).
Recent reports mention that some taxa with di erent morphological-cy-
tological characters are spreading in semi natural or urban habitats, having es-
caped from gardens (C et al. 2006). By studying ivy diversity in Hungary,
we detected an outstanding Hedera taxon with a speci c habit, bearing a series
of distinguishable morphological-phenological traits and with di erent eco-
logical demands. Earlier, this was considered to be H. hibernica (U and
B-H 1999). In the last 15–20 years, we observed that this taxon
exhibits invasive behaviour spreading in many semi natural habitats and also in
urban ecosystems.
In the course of the detailed study of cultivated ivy specimens based on
 ow-cytometry, we also detected triploid ivies that were formerly considered
Hedera helix.
Based on the results of our detailed comparative study of Hedera speci-
mens, we consider the need to re-evaluate the taxonomic status of the ivy taxon
spreading in Hungary and we propose a new name with the related diagnosis.
Accordingly, our aims were (i) to identify, describe, and characterize the Hedera
taxon that is spreading in Hungarian habitats and formerly misidenti ed as H.
hibernica; (ii) to describe and characterize newly identi ed triploid Hedera taxa
(2n = 72), which were formerly considered cultivated varieties of the diploid H.
helix.

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 227
Studia bot. hung. 48(2), 2017
MATERIAL AND METHODS
Studied specimens
 e specimens described here were collected in the period between 2004
and 2007. Geographical coordinates of the type specimens were recorded us-
ing Garmin eTrex Legend GPS. Living material of all taxa is maintained in the
ivy collection of the Soroksár Botanical Garden of the Szent István University
(Budapest).  is garden is situated in the northwestern margin of the Great
Hungarian Plain, at the edge of Budapest. It is a lowland area with a continental
climate, cold winters, and long-lasting droughts in the summer. In order to test
ecological demands and behaviour of the studied Hedera taxa we planted 10 test
individuals on di erent sites in the Soroksár Botanical Garden and in particu-
lar in a fenced-in area where an oak forest community has been preserved. We
also planted 50 individuals in the Buda Arboretum of the Szent István University
(Budapest) situated on the southern part of the Gellért Hill, where the climate
is milder and the territory is under sub-Mediterranean in uence. Recent studies
on morphology and ecological demands were preceded by a 20 years observation
period (U and B-H 1999).
Flow cytometry and chromosome counting
To distinguish the di erent cytotypes in the  rst approach we used  ow-
cytometrical analysis with PARTEC I (Partec GmbH, Münster, Germany). Fresh
leaves were collected and a 1 cm2 area was introduced in LB01 isolating bu er ac-
cording to D et al. (1989). A er  ltration, 1 ml DAPI (conc. 25 ng/ml ) was
added. Nuclei were stained in 1–5 minutes. We used as control the diploid Hedera
helix ‘Zebegény’ (B-H et al. 2005a, b). A er we had determined
ploidy levels by  ow cytometry, chromosome counting was done on altogether
10 specimens.  e control was the diploid H. helix ‘Zebegény’. Chromosomes
were revealed from the root tips according to L et al. (2007). Ivy cuttings
were rooted in perlite in dark chamber using rooting hormone. Root tips were
treated with colchicine,  rst of 0.05% concentration for 30 min., then again with
a concentration of 0.025% for 60 min. Fixing was done with 45% acetic acid, then
hydrolysis in 1N HCl at 60 °C for 5 min., pressing under a coverslip. Staining was
done with 2% acetocarmine for 24 hours at room temperature.
Morphological study and germination power
To distinguish the new specimens from Hedera helix and H. hibernica, a
morphological study was carried out based on leaf morphometry and detailed

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
228
Studia bot. hung. 48(2), 2017
study of other vegetative and reproductive organs. Morphometry was carried out
on H. helix ‘Zebegény’, H. hibernica ‘Hamilton’, the new diploid taxon, and the
two triploids. Leaves were collected from emerging (orthotrop) vegetative shoots
and 30 leaves/taxon were measured. Morphometrical characters were recorded
as follows: 1 = Length of petiole, (LPET, mm); 2 = Highest length of a lamina,
(LMAX, mm); 3 = Length from the base point to the highest width of a leaf,
(WLOC, mm); 4 = Length from the base point to the right apical cut (diagonal
length), (DIAG, mm); 5 = Highest width of the leaf, (WMAX, mm); 6 = Length
of the vein in the main side lobe of the right side of the lamina, (SVEIN, mm); 7
= Highest length of the leaf measured on the right side of the lamina, (LAMIN,
mm); 8 = Highest length of the main central lobe, (MAINL, mm); 9 = Highest
width of the main central lobe, (MAINW, mm); 10 = Angle of the side bay of the
right side of the lamina (ANGLE, mm) (Fig. 1).
IBM SPSS 2.0 (IBM Corp. 2013) statistical so ware was used to perform
univariate and multivariate statistical analysis. Averages and standard deviations
of morphological traits (variables) were used to compare means and statistical
significances.  e diagrams presented below show variation (standard deviation)
and signi cant di erences calculated with ANOVA.
Reproductive power and germination potential were studied by comparing
the germination rate of H. helix ‘Zebegény’ and the new diploid taxon. 120 seeds
were sewed in a propagation tray in normal garden soil and kept in a green house.
To evaluate the reproductive potential of each taxon involved (H. helix
‘Zebegény’, H. hibernica ‘Hamilton’, and the new diploid taxon) in this study we
counted the average number of fruit production/ramet. 3 in orescences from 5
individuals of each taxon were measured (fruits of altogether 135 in orescences).
Additional specimens (28 sheets) held in the collection of the Hungarian
National History Museum (BP) were also examined for diagnostic characters.
 ese are listed below. Herbarium specimens identi ed by us as H. crebrescens,
are marked with an asterisk, all others are H. helix: HUNGARY. Kerepes: 207
m, June 1856, Bernátsky, (BP120833); Buda Mountains, Jánoshegy: 528 m, 12
March 1870, L. Szépligeti, (BP120853); Jánoshegy: 528 m, September 1862,
J. Tauscher (BP120861)*; Zala, Szentgyörgyhegy: 415 m, 1872, S. Jávorka,
(BP120851); Murakeresztúr, Gyurgyácerdő: 25 September 1937, Jávorka and
Zólyomi (BP120817); Budapest: Remetehegy: 423 m. 17 December 1916,
Á. Boros (BP568834); Kaposújlak, Szarkavár: 153 m, 5 April 1926, Á. Boros
(BP444903)*; Rajka, Dunakiliti: 114 m 11 April 1920, Á. Boros (BP444905);
Vértestolna, Hajagoshegy: 450 m, 26 April 1931, Á. Boros (BP444931);
Vértestolna, Szénáshegy 400 m, 20 September 2001, Z. Barina (BP636676)*;
Nyergesújfalu: 103 m, 10 September 2001, Z. Barina (BP636289)*; Nagykovácsi:
139 m, 18 August 1997, L. Felföldy (BP291986); Visegrád: 242 m, 12 June 1921, J.

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 229
Studia bot. hung. 48(2), 2017
Fig. 1. Measured morphometrical characters of an ivy leaf. 1 = LPET: length of petiole,
2 = LMAX: highest length of a lamina, 3 = WLOC: length from the base point to the
WMAX, 4 = DIAG: length from the base point to the right apical cut (diagonal length),
5 = WMAX: highest width of a leaf, 6 = SVEIN: length of the vein in the main side lobe
of the right side of the lamina, 7 = LAMIN: highest length of a leaf measured on the right
side of the lamina, 8 = MAINL : highest length of the main central lobe, 9 = MAINW:
highest width of the main central lobe, 10 = ANGLE: angle of the side bay of the right
side of the lamina.

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
230
Studia bot. hung. 48(2), 2017
Andrasovszky (BP269647)*; Sármellék, Zalavár: 124 m, 5 April 1952, Á. Károlyi
(BP295358)*; Nagyharsány: 166 m, 26 February 1935, A. Pénzes (BP374680);
SLOVAKIA. Prenčov Tepličky: 325 m, 1876, Andr. Kmet, (BP120834); Fatra,
Likavka valley: 494 m, 22 August 1893, F. Pax, (BP120879); Tatra, Ľubochňa (Fe-
nyő háza): 750 m, 3 August 1906, F. Pax, (BP120872); Chocrscheit, Wald Pocs-
kay: 800 m, 21 May 1899, F. Pax, (BP120878); Bratislava (Pozsony),  ebener
Kogel: 18 April 1907, F. Pax (BP120874)*; Jasenová: 700 m, 7 April 1897, F. Pax,
(BP 132275); Bratislava (Pozsony): 1909, S. Mágocsy (BP568851); ROMANIA.
Portile de  er (Kazanpass): 70 m, 22 August 1901, F. Pax, (BP 120884); Retezat
Mt., Cerna valley: 170 m, 28 August 1897, F. Pax, (BP120883); Pojana Ruska:
800 m 15 August 1890, F. Pax, (BP120882); Sibiu (Hermannstadt): 420 m, 15
September 1893, Kimakowicz, (BP120880); Piatra Rosie, Petrosani (Petrozsény):
1000 m, 9 August 1901, F. Pax, (BP120881); Brasov, Cristian (Keresztényfalu):
600 m, 15 March 1906, G. Moesz, (BP120850); CROATIA. Fiume, Musuliensky
potok: 2 June 1907, Filarszky, Kümmerle and Moesz (BP5855); Fiume: 16 April
1908, G. Lengyel (BP568856).
Vouchers of the new taxa described here are deposited in BP, while some
isotypes are also in private collections at Mária Höhn and Hugh McAllister.  e
two triploid taxa we describe here were formerly included in two cytological
studies, one involving 30 type specimens from the ivy collection of the Soroksár
Botanical Garden (B et al. 2005a) and another with an extended sample
size of 80, also from the collection (B et al. 2006, L et al. 2007).
Among the ivy samples studied here there were species and also cultivated speci-
mens of commercial origin, cultivars selected by us or cultivars originating in
botanical gardens abroad. Research activities and the selection of the ivy col-
lection were performed in the Soroksár Botanical Garden, beginning from the
1970s. Finally, we constructed a key for identi cation that includes all species
mentioned in MA and R (1997) except for H. cypria (con-
sidered as subspecies based on V and V 2010) and including the
newly presented taxa.
RESULTS
Taxonomic treatment
Hedera crebrescens M. Bényei-Himmer et M. Höhn, spec. no.
Type: Hungary, Budapest, Gellért Hill, southern slope, 126 m, GPS 47° 28’
50.5”; 19° 02’ 25.8”, 03.10. 2015. Holotype: BP745240, (Fig. 2), isotype: BP745237

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 231
Studia bot. hung. 48(2), 2017
Fig. 2.  e holotype specimen of Hedera crebrescens.

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
232
Studia bot. hung. 48(2), 2017
Diagnosis: Leaf shape on the horizontally creeping shoots is triangular,
slightly trilobed, lobes are obtuse and the dense nervation is white.  e leaf base is
cordate, facing sites overlap (Fig. 4). Leaves on the vertically emerging (orthotrop)
shoots are large, 10–16 cm in diameter, with 3–5 lobes and a wider apical lobe.
 is dome-shaped apical lobe is much larger than the lateral lobes (Fig. 4).  e
leaves of the  owering, fruiting shoots are cordate.  e axis of the in orescence is
short, squat, 3–5 cm, with a few lateral umbels. Under the terminal umbel on the
central axis usually there is a solitary  ower (Fig. 5).  e fruits are dark green, and
turn black when ripe. Because of the short peduncules, fruits are densely packed.
Fruits have 3–5 mature seeds. Growth is vigorous. H. crebrescens is slightly frost
sensitive. In cold winters (when temperatures fall below –10° C and cold spells
last longer) leaves are damaged, but shoots usually survive and regenerate in the
spring. H. crebrescens spreads easily by seeds. It is considered to have all the prop-
erties of an invasive plant, and it escapes successfully from cultivated areas.
Chromosome number: diploid 2n = 2x = 48 (Fig. 3).
Etymology:  e epithet “crebrescens” refers to the vigorous growth of the
plants.
Fig. 3. Chromosome number of H. crebrescens (A, B) and H. hibernica (C, D). Cytological features
were recorded using a 40× objective (magni cation of 400× (A, C) and 800× (B, D) in an optical
microscope. Photo credit: Pintér I. and Lengyel Sz. (P ined.).

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 233
Studia bot. hung. 48(2), 2017
Fig. 4. Leaf characters on the emerging shoots of Hedera hibernica (le ) H. helix (central) and H.
crebrescens (right), Scale bars=(A, B) 50 mm. A: apical lobe (triangular, elongate, dome-shaped) B:
leaf base (open, open, overlapping sites).
Fig. 5. Morphological characteristics of Hedera crebrescens (A: comparison of fruiting shoots of H.
hibernica (le ), H. crebrescens (only the apical in orescence developed) (center) and H. helix (right),
B: ripening fruits of H. crebrescens, and (C): early winter frost damage of H. crebrescens D: main
morphological characteristics (in orescence and leaves) of H. crebrescens. Scale bars = (A, D) 50 mm.

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
234
Studia bot. hung. 48(2), 2017
Distribution: As a fast-growing, easily spreading taxon H. crebrescens most
frequently grows along railways (from Budapest to Rákospalota-Újpest, Göd,
Vác, Kismaros, and Nagymaros towards Zebegény). It can be found also near
Lake Balaton and in the area around Szombathely. It o en grows in association
with Ailanthus altissima, Acer negundo, Celtis occidentalis, Robinia pseudo-acacia
and Rubus  uticosus. It is widespread in cemeteries and their surroundings, such
as the Farkasrét Cemetery in Budapest or cemeteries in Eger, Keszthely, and
Kecskemét. Other situations in which it can be found are unmaintained gardens,
park forests in the Pil is Mountains (Csobánka local ity), Kaposvár, Székesfehérvár,
gallery forests alongside rivers, for instance in the Bakony Mountains along the
Gaja river (Fig. 6). We have detected this taxon outside Hungary in several loca-
tions, for instance western Ukraine (in Transcarpathia near Uzhhorod) and in
the surroundings of small cities where it has been naturalized. We found it also in
Vienna (Austria), southern parts of Slovakia, Germany, and the Netherlands, but
occurring mainly in parks.
It is important to consider this new taxon as distinct from H. helix and H. hi-
bernica not only because of its di erent morphological traits but also because of
Fig. 6. Geographical sites of the Hedera crebrescens records across Hungary: Budapest (János
Hill, Sas Hill, Soroksár, Gellért Hill, Rákospalota-Újpest), Csobánka, Debrecen, Eger, Érsek-
vadkert, Gaja river, Göd, Gyöngyös, Gyula, Kaposújlak, Káloz, Kecskemét, Keszthely, Kismaros,
Mezőhegyes, Mosonmagyaróvár, Nagymaros, Nyírbátor, Nyíregyháza, Óbánya, Pécs, Polgárdi,
Sióagárd, Sopron, Szeged, Szentgothárd (Pityerszer), Szombathely, Tiszaadony, Vác, Várgesztes,
Verőce (further localities are listed in Material and Methods).

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 235
Studia bot. hung. 48(2), 2017
its distinct behaviour, speci cally that it is capable of becoming invasive because
of its successful propagation ability and increased reproductive potential.
Habitat requirements: H. crebrescens prefers a semi-humid environment
and shady places with an equilibrated water supply. By growing under scrub or
hedges, this ivy is able to reduce radiation or frost damage. It may grow in rural
environments,  lling gaps around houses, in stone cracks, or even in apertures in
concrete. It also frequently occupies natural sites where H. helix is not present,
such as islands along rivers and in gallery forests. On the other hand, it is also
a drought tolerant taxon. H. crebrescens is slightly frost sensitive. In cold win-
ters (e.g. 1981/1982; 1996/1997 and 2016/2017) when temperature falls below
–10°C and persist for some time, leaves are damaged and decay (Fig. 5C).
Leaf morphometry: Variance analysis was performed on the basis of 10
morphological traits using SPSS statistical method. Accordingly, leaf shape sig-
ni cantly di ers both from Hedera helix and H. hibernica based on morpholog-
ical traits. Bar charts of the six most discriminant characters are presented in
Figure 7.
Hedera crebrescens signi cantly di ers from H. helix and H. hibernica in six
measured parameters: DIAG, SVEIN, LAMIN, MAINL, MAINW, WLOC. All
parameters of H. crebrescens had higher values than the two triploid specimens
(Hedera × soroksarensis and H. × schmidtii, see later) and H. helix. Moreover at
LAMIN, MAINL, MAINW parameters of H. crebrescens had the highest value
among all taxa studied (Fig. 7).
By comparing Hedera crebrescens with H. hibernica we found signi cant
di erences in two more parameters: WLOC, DIAG, WMAX, SVEIN, LAMIN,
MAINL, MAINW, ANGLE. H. crebrescens showed the highest length either
WLOC, LAMIN or MAINL. Furthermore, H. crebrescens had higher values in
width, i.e. wider leaves, than H. hibernica according to WMAX.  e angle of the
lateral sinuses of the right side of the lamina (ANGLE) showed that H. crebrescens
leaves have acute angles, and H. hibernica has obtuse angle. H. crebrescens signi -
cantly di ers in all measured parameters from the diploid H. helix (Fig. 7).
Nomenclatural notes: Until now, H. crebrescens has been identi ed in
Hungary as H. hibernica by most gardeners and horticultural experts. H. hiberni-
ca has been listed in most of the price lists of nurseries from Hungary since 1815.
It is documented to have been commercially available since 1875 (S
1875). D C (1830: 261–265) mentioned it as Hedera helix vulgaris
“Hybernica hortul” by adding the comment “et foliis majoribus”.
Hedera helix var. hibernica (as H. H. 4. hibernica) was described by Georg
Kirchner in 1864 (in P and K 1864).  e diagnosis includes
statements mostly on the geographical origin of the new taxon (in con ict with
Art. 38.3) and a single statement about speci c characters referred to its large

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
236
Studia bot. hung. 48(2), 2017
Fig. 7. Main metric characters of the studied Hedera taxa, A: WLOC = length from the basepoint
to the WMAX; B = DIAG: length from the basepoint to the right apical cut (diagonal length); C
= SVEIN: length of the vein in the main side lobe of the right side of the lamina; D = LAMIN:
highest length of a leaf measured on the right side of the lamina; E = MAINL: highest length of the
main central lobe; F = MAINW: highest width of the main central lobe.

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 237
Studia bot. hung. 48(2), 2017
leaves (“Grossblättriger, als der gemeine Epheu”). Later, J (1865: 176) pro-
vided a detailed description for var. hibernica.
K (1869) considered this taxon to have originated in Ireland, but to
have been cultivated largely in England. According to the nomenclature, Koch
concluded that all cultivated garden ivy from Belgium and France should be
considered “Hibernica”.  is assumption is probably the origin of the nomen-
clature used in Hungary for all ivies that di er from the autochthonous H. helix.
However, Koch mentioned that H. hibernica leaves are light-green, plants are fast
growing, and are sensible to frost. All these characters  t the taxon we are de-
scribing here as H. crebrescens.
Under the name H. hibernica, Carrière discussed two subtaxa (H. hibernica
aureo-marginata and H. hibernica marginata) without providing a description or
diagnosis of H. hibernica and without providing a reference to Kirchner’s valid
description (C 1890). Doing so, he created a nomen nudum for H. hiber-
nica (Art. 38.1). Referring to Kirchner, B (1914) created validly the new com-
bination H. hibernica based on the basionym H. helix var. hibernica. J
(1954) mentioned Hedera hibernica as a tetraploid ivy.
According to S (1912), H. hibernica is a hybrid between H. helix
and H. canariensis (diploid).  e hybrid origin of H. crebrescens might be sup-
ported by its vigour, fast growth, and high seed production capacity. In its sensi-
tivity to frost also resembles some subtropical taxa, such as the diploid H. azorica,
H. nepalensis, H. canarensis, H. maroccana, and H. rhombea.
T (1912) notes that leaf petioles of H. hibernica grow vertically even
on the creeping shoots on the ground. He also mentioned the strong  owering
capability and its sensitivity to frost in northern and central Germany. He em-
phasized that the anthocyanin colouring of the leaves may indicate northern dis-
tribution. Based on our observations in the Soroksár Botanical Garden in the
winter of 1981–82, when temperatures fell below –20 degrees for a longer period
of time, among the ivies growing upwards on tree trunks only H. crebrescens suf-
fered frost damage.
Diagnostic characters (from Hedera helix subsp. helix and H. hibernica): H.
hibernica is a tetraploid taxon (Fig. 3C, D). According to MA (1981),
for Hedera hibernica the most detailed description was given by B (1914).
On the young spring (orthotrop) shoots H. crebrescens has very characteris-
tic leaves.  e apical lobe is broad, dome-shaped, and widest on the lower third
part (not exactly at the lobe base but a little higher).  e upper third section be-
gins to narrow sharply towards the tip (Fig. 4 and 5D). Both lateral leaf lobes are
obtuse. In H. hibernica the apical lobe is not dome-shaped. It has mostly parallel
margins or slightly widening margins at the lobe-base (Fig. 4, Table 1). H. hiber-
nica has  ve leaf lobes (Fig. 8).

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
238
Studia bot. hung. 48(2), 2017
 e texture of the blade is thick with a well-developed mesophyllum that is
20% thicker than that of H. helix.  e palisade parenchyma is 15–20% broader
than in the leaf of H. helix.  e leaf shape of H. crebrescens in most cases is longer
than wide, as is the case with H. hibernica.  e development of lateral shoots
with very short internodes bearing small, light green alternating leaves is also
characteristic. During the winter, mostly in sunny cold places, leaves of H. creb-
rescens turn yellow or bronze or even claret, but the colour of their veins remains
unchanged.
Table 1. Comparison of main morphological traits and conservation status of three Hedera spe-
cies.
H. crebrescens H. helix H. hibernica
ploidy level diploid diploid tetraploid
shoot reddish green brownish green green
leaves
– vegetative creeping
shoot
leaf blade triangular,
leaf base slightly
overlapping
nervation white,
3–5 lobed, not over-
lapping leaf base
5 lobes, not overlap-
ping leaf base
– vegetative emerging
shoot
3–5 lobes, lateral
lobes obtuse, apical
lobe dome-shaped
3–7 lobes, apical
lobe elongate
5 lobes, apical lobe
triangular or with
parallel margins, not
dome-shaped
leaves on reproductive
shoot
heart shaped, leaf-
base cordate
elongate or oval,
leaf-base cuneate
triangular-ovate, leaf-
base truncate
hairs white, stellate, always
appressed
white, stellate white, stellate, erect,
rays in two directions
in orescence main axis thick, 3–5
cm,  owers crowded,
one  ower below the
apical umbel, apical
umbel fruiting
main axis 6–9 cm,
sparse, third rank-
ing umbels present,
lateral umbels fruit-
ing
main axis 8–10 cm,
sparse, third ranking
umbels present, rarely
fruiting
 owering months September–October August–October October–November
fruits slightly  attened,
globose, not protrud-
ing discus
reniform, protrud-
ing discus
rarely fertile, not
protruding discus
seed production 4–5 seeds/fruit, 114
fruits/ramet
1–3 seeds/fruit, 41
fruits/ramet
0–2 seeds/fruit, 51
fruits/ramet
germination 82% 42% no data available
hardiness frost sensitive winter hardy slightly winter hardy
nature conservation
status
propagating, invasive natural cultivated

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 239
Studia bot. hung. 48(2), 2017
Reproductive shoots may develop close to the ground, as they do not need as
much sunlight as the reproductive shoots of H. helix. Leaf blades on the reproduc-
tive shoots are heart shaped, with a cordate leaf base and acuminate apex, but they
are not sharply cuspidate. In contrast, leaves on the reproductive shoots in Hedera
helix are largely elongate or oval with a cuneate leaf base, while leaves on the re-
productive shoots of H. hibernica are triangular with a truncated leaf base (Fig. 8).
In orescence of H. crebrescens develops on a short (3–5 cm) main axis with
usually only one umbel (Fig. 5). In the case of H. helix, this main axis of the in o-
rescence is much longer, and it is thin, with lateral branches being distant from
one another and developing in August.
On the axis of H. crebrescens below the upper umbel there is always a solitary
 ower (Fig. 5). Flower peduncles in the fruiting umbels are quite short, so the de-
veloping fruits are very close to one another and are densely packed like a stu ed
ball (Fig. 5).  is attribute has ornamental value and cannot be seen in H. helix
or in H. hibernica (Fig. 6A). Moreover, in orescences of H. helix and H. hibernica
always have third-ranking umbels, while H. crebrescens does not.  e  owering
period of H. crebrescens in Hungary starts two weeks later than the  owering pe-
riod of H. helix and usually two weeks earlier compared to H. hibernica. Flowers
of H. hibernica open only in October and November, and o en fertilization fails
Fig. 8. Morphological variability of leaves of Hedera hibernica A: leaf on the creeping shoot (bot-
tom le ), vertically emerging shoot (bottom right), generative shoot (top center) and Hedera helix
subsp. helix; B: leaf on the creeping shoot (bottom right), vertically emerging shoot (bottom le ),
generative shoot (top center). Scale bars = (A, B) 50 mm.

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
240
Studia bot. hung. 48(2), 2017
(which is why this taxon could not become invasive). When fertilization is suc-
cessful, fruiting umbels in H. hibernica are big and loose and the in orescence is a
compound cyme (Fig. 5A). In H. crebrescens fruits develop from the upper umbel
and lateral umbels dry and fall o . Fruits are slightly  attened globose. When rip-
ening, they change color from dark green to black.  e disc of the  ower does not
protrude, as it does in the case of Hedera helix. Fruits remain on the plants even
into April, and they contain 3–5 rounded-shaped seeds. H. helix has 1–3 kidney-
shaped seeds/fruit.  e fruits of H. helix ripen in February and are quickly eaten
by birds.  e germination rate of seeds is also much higher in H. crebrescens com-
pared to H. helix.
Our study has revealed that seed production/ramet in H. crebrescens is high-
er than in H. helix and H. hibernica.  e average seed number of one ramet in H.
crebrescens was 114 seeds, while in the case of H. helix it was only 41 and in the
case of H. hibernica ‘Hamilton’ was 51.
Seeds of H. crebrescens are dispersed by thrushes. In thrush droppings there
are sometimes large amounts of viable seeds which can be found germinating
in clusters. Cotyledons of the seedlings are more rounded than the seedlings
of H. helix.  e vigorous, rapidly growing plants produce reproductive shoots
in a short period of time and yield large amount of fruits with many seeds.  e
germination capacity is also considerably higher than that of H. helix.  e gen-
eral opinion has been accepted up to the present that H. helix tends to behave
like a weed (G and V 1992, M 1958, S 2004,
C et al. 2006, U and B-H 1999). On the contrary,
we do consider that H. crebrescens is the taxon which is spreading behaving like
a weed. We performed a germination experiment to study the germination ca-
pacity of seeds.  e germination test was a case study using 120 seeds/taxa from
di erent clones belonging to H. helix and H. crebrescens. Based on our observa-
tions, the germination capacity of H. crebrescens was 82%, which considerably
surpasses that of H. helix, even of cultivars which had 42% as their highest ger-
mination percentage.
By revising herbarium specimens of BP based on diagnostic morphological
characters for H. crebrescens, such as the dome-shaped apical lobe and obtuse
lateral leaf lobes, we identi ed 7 specimens originating mainly in Hungary and
Slovakia beginning in the late nineteenth century. However, herbariums were
not accurate for further morphometrical analysis because in most cases both leaf
types, i.e. those from the vegetative and reproductive shoots, were not available.
Pharmaceutical use: Because of its chemical compounds, Hedera species
have pharmaceutical value. Recent studies have revealed biologically active com-
pounds, in particular triterpene saponins, the bidesmosidic glycosides of hedera-
genin, inositol, carotenes, clorogenic acid, tannins, formic acid, and malic acid,

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 241
Studia bot. hung. 48(2), 2017
all of which have medicinal uses. Leaf extracts of ivy have important spasmolytic,
antimicrobial, analgesic, anthelmintic, antitrypanosomial, antileishmanial, an-
titumor, and antimutagenic e ects (L et al. 2010). H. crebrescens grows
more rapidly, has a higher biomass, and is easier to cultivate than H. helix. Target
research has not yet been done, but for pharmaceutically active compounds this
taxon has already been cultivated in Hungary near Cegléd.
Triploid Hedera specimens
In the  rst decade of this century, we studied the ivy specimens, species,
and cultivars growing in the Soroksár Botanical Garden using  ow-cytometry.
In some cases we found di erent ploidy levels compared to previous reports, and
we detected triploids. In most cases in which  ow-cytometry indicated di erent
ploidy levels from what was expected we checked by counting the chromosome
number.  e triploid specimens of presumably hybrid origin were previously
classi ed as cultivars of H. helix or H. hibernica. Triploids were also mentioned
by M et al. (2017). Based on our cytological and morphological results,
we describe two triploid cytotypes here.
Hedera × soroksarensis M. Bényei-Himmer et M. Höhn in MA and
M (2017: 401)
Type: Hungary, Budapest: Soroksár Botanical Garden, 100 m. GPS 47°
14’ 32.6”; 19° 54’ 38.5”. Holotype: BP745235 (Fig. 9), isotypes: BP745237,
WSY0129182
Chromosome number: triploid: 2n = 3x = 72 (Fig. 10).
Etymology: the epithet ’soroksarensis’ comes from the name of the botanical
garden where this taxon was  rst observed.
Origin: Based on personal observations made in recent decades, a variety of
ivy specimens were involved in selection and multiplication of new cultivars. One
of these with conspicuous leaf morphology was nominated for national approval
in 2001 by Márta Bényei-Himmer as a new variety, with the name Hedera helix
‘Negro’. In 2004, this variety was registered o cially. Based on  ow-cytometry
and chromosome counting this taxon was shown to be triploid (2n = 72), produc-
ing only sterile in orescences (Fig. 11).
Habitat: Planted individuals are in the botanical garden in Soroksár,
Hungary and also in the Buda Arboretum, where vegetative shoots form dense,
crowded patches. It has been observed in lowland forests of Hungary, where it
grows mainly in association with Robinia pseudo-acacia, Pyrus pyraster, Celtis oc-
cidentalis, Elaeagnus angustifolia, Ligustrum vulgare, Sambucus nigra, Crataegus
monogyna and Rosa canina.

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
242
Studia bot. hung. 48(2), 2017
Fig. 9.  e holotype specimen of the triploid Hedera taxa: H. × soroksarensis.

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 243
Studia bot. hung. 48(2), 2017
Fig. 10. Chromosome number of the triploid Hedera taxa: H. × soroksarensis (‘Negro’) (A), H. ×
schmidtii. (B) and H. × soroksarensis (‘Woerneri’) (C). Cytological features were recorded using a
40× objective (magni cation of 400× (A, B, C) in an optical microscope.Photo credit: Pintér I. and
Lengyel Sz. (P ined.).
Fig. 11. Sterile in orescences of Hedera × soroksarensis.

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
244
Studia bot. hung. 48(2), 2017
Diagnostic characters (from H. helix subsp. helix and H. hibernica):
Compared to H. helix, in orescences can develop near the ground at the soil sur-
face or at low heights by climbing on tree trunks. Trichomes are more numerous
on the veins and in the angles between veins, but they are most dense on the main
axis of the in orescence. Leaves of the creeping shoots most closely resemble
those of the tetraploid H. hibernica but they are smaller and dark green.  e two
basal lobes are short.  e middle two lobes are wider, while the apical lobe has a
wide base tapering to the apex. Most conspicuous is the dark green colour of the
leaf blade surface, which on the  owering shoots is pale, not shiny.  ey measure
5–8 × 7–9 cm and are egg-shaped and slightly asymmetric, tapering toward the
apex (Fig. 12).  e in orescences resemble those of H. hibernica but the  owers
are less developed.  e axis of the in orescence is 4–6 cm (H. hibernica is longer
up to 6–10 cm), having 2–3 lateral umbels.
Horticultural uses: As it has a moderate growth vigour (around 40–60 cm
yearly growth increment) but is not invasive, with its dark green leaves this taxon is
one of the best ivies to use as shade-tolerant ground cover to replace lawns or cover
bare walls. It can be planted in gardens and parks, as it is not invasive and is resist-
ant to diseases, drought, and frost.  ere is no need to water, as it is drought toler-
ant, and the dense shoot network provides an excellent uniform dark-green cover.
Hedera hibernica ’Woerneri’ described earlier by Jenny (1964) is also a trip-
loid variety of H. × soroksarensis (B-H and H 2017: 301).
Fig. 12. Creeping shoots: A: Hedera × soroksarensis with the dark green leaves, B: Hedera ×
schmidtii with slightly triangular emerald leaves with small lobes.

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 245
Studia bot. hung. 48(2), 2017
Hedera × schmidtii M. Bényei-Himmer, spec. no.
Type: Humgary, Zebegény, northern slope, GPS 47° 47’ 50.2”; 18° 54’ 44.9”.
Holotype: BP 745238 (Fig. 13), isotype: BP 745239.
Diagnosis: Shoots are purple-brown with 8–10 cm long internodes. It has
mainly creeping shoots, the leaves of which are 7–8 × 8–9 cm, triangular, or
slightly trilobed.  e leaf base is deeply cordate. On the emerging vertical shoots
leaves are more deeply trilobed.  e colour of the leaf surface is emerald green
with white venation.  e main vein with the  rst rank lateral veins protrudes
from the surface. Lateral veins form right angles with the main vein.  e un-
derside of the leaf is pale.  e leaf is skin-like and medium thick in texture. Leaf
margins are usually slightly re exed. Stellate trichomes are white with mostly 4
rays which both protrude from and lie parallel to the leaf blade.  e petiole is
purple-brown and 6–9 cm long.  is taxon develops  owering shoots at a rela-
tively old age, when it is older than 10 years, at a height of 3–4 m.  e main axis
of the in orescence is 5–6 cm, with only a few (3–4) rami cations.  e in ores-
cences and the umbels are loose. Fruits are slightly elongate to globose. We have
not yet found germinated seeds.
Chromosome number: triploid: 2n = 3x = 72 (Fig. 10).
Etymology:  e epithet “schmidtii” comes from the name of professor
Gábor Schmidt, who was the head of the Buda Arboretum where this taxon was
preserved.
Origin:  is taxon originates from the Börzsöny Mountains (northeastern
Hungary). It is maintained ex situ in the Soroksár Botanical Garden. It was nomi-
nated for national approval in 2001 by Márta Bényei-Himmer as a new variety
with the name Hedera helix ‘Nagybörzsöny’. In 2004, this variety was o cially
registered.
Habitat: At the original site, the location from which this triploid was  rst
discovered in the Börzsöny Mountains, it occurs in a managed sessile oak forest,
where it propagates only vegetatively.  e accompanying species are Acer camp-
estre, Pyrus pyraster, Robinia pseudo-acacia, Sambucus nigra, Cornus sanguinea,
Cornus mas, Syringa vulgaris and Ligustrum vulgare.
Diagnostic characters (from Hedera helix subsp. helix and H. hibernica): We
have already planted specimens in the botanical garden in Soroksár, Hungary
and also in the Budai Arboretum. Our experience shows that vegetative shoots
form uniform, medium-crowded patches.
 is taxon grows mainly close to the soil surface. Flowering umbels develop
only rarely, on 2–3 m high emerging shoots. Like the underside of the leaf, the
upper surface and the area among the veins are hairy (Hedera × soroksarensis
has hairs only on the veins and at the edge of vein rami cations).  e emerald

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
246
Studia bot. hung. 48(2), 2017
Fig. 13.  e holotype specimen of the triploid Hedera taxa: Hedera × schmidtii.

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 247
Studia bot. hung. 48(2), 2017
green colour of the leaf with white venation is speci c to this taxon. Leaves of
the  owering (adult) shoots are wide-ovate and triangular, with a truncated leaf
base, which is a feature it has in common with H. hibernica.  e  owering shoots
resemble those of H. hibernica with their straight, truncated leaf bases, but the
leaf apex is not twisted. It grows vigorously (60–80 cm is annual average growth
increment), but it is not invasive.
Horticultural uses: As it has a medium growth vigour but is not invasive,
with its dark emerald green leaves H. × schmidtii is suitable to use as a shade-
tolerant ground cover to replace lawns or cover bare walls (Fig. 12). It is suitable
for planting in gardens and parks, as it is non-invasive and resistant to diseases,
drought, and frost.
 e triploid cultivars described here di er signi cantly from H. hibernica
and H. crebrescens in  ve morphological parameters (WLOC, DIAG, SVEIN,
LAMIN, MAINW) (Fig. 7). In the case of H. helix, these cultivars signi cantly
di er in only one parameter (MAINL). Only H. × soroksarensis showed distinct
values of LAMIN and MAINW (Fig. 7).
Statistical  ndings indicated signi cant di erences between the two trip-
loid cultivars in three variables: LAMIN, MAINL, MAINW. At these parame-
ters, H. × soroksarensis always showed smaller values than H. × schmidtii (Fig. 7).
Identi cation key for cultivated and native Hedera the taxa in the
Carpathian Basin
We consider in the key altogether 11 species including the new taxa and
the two triploids.  is number is di erent compared to the 12 species recently
published by MA and M (2017: 141). We did not consider
here the frost sensible Mediterranean species like H. iberica and H. maderensis,
without any importance in Central East Europe, only H. canariensis which was
several times confused with H. algeriensis.
1a Trichomes are greyish, stellate with 4–10 rays ............................................................................... 2
1b Trichomes are yellowish brown,  at, scale-like (squamiform), in bundles ................................ 5
2a Trichomes are not emerging from the plane of the leaf, rays of the trichomes face two direc-
tions (bifurcate). Leaves on the ground creeping shoots are pentagonal with  ve equal sized
lobes. Leaf blades are funnel shaped, 8–10 cm, dark green.  e petiole is very long , even 20 cm
in length. Leaves does not change colour during winter.  e vertically emerging shoots have
three to  ve lobes, and are wider than longer.  e leaves of the  owering, fruiting shoots are
oval with acuminate apex (pointed) tip.  e in orescence is a loose and compound corymb.
 e species is  owering in late September or October.  e fruits are developing from the lat-
eral umbels, frequently remain immature. Tetraploid species, its cultivars are widely planted
........................................................................................... H. hibernica (Kirschner) Bean (Fig. 8A)
2b Trichomes emerge from the plane of the leaf ................................................................................. 3

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
248
Studia bot. hung. 48(2), 2017
3a  e in orescence axis is 3–5 cm long, the fruits develop only from the terminal umbel.  e
lateral umbels decay and fall a er  owering.  e leaves of the ground creeping shoots are 5–8
cm in diameter and slightly lobed with three lobes at the leaf base (triangular). Leaves are bright
green, the veins are light green.  e vertically emerging shoots have leaves with 3–5 lobes with a
broad central lobe.  is dome-shaped broad lobe is much more developed than the lateral lobes
(Fig. 4A).  e leaves of the  owering, fruiting shoots are heart shaped with cordate leaf base.  e
leaf blade is large, 10–16 cm long, the trichomes have 7–12 rays.  e axis of the in orescence
is short, squat of 3–5 cm with few lateral umbels. Under the terminal umbel on the central axis
always one lonely  ower develops (Fig. 5D).  e pedicel of the  owers are short –1 cm, there-
fore the ripening fruits are densely packed. Flowering period is from late August to September.
 e fruits are dark green and becoming black when ripen. Fruits have 3–5 seed.  e generative
(adult) stage develops early, even on the ground level. In wintertime leaves can change their
colour to claret on the sun, but the veins remain green. During very cold winters the leaves freeze
and fall, but the shoots survive. Diploid taxon. Widely planted, but spreads also spontaneously
and tends to be invasive ........................ H. crebrescens M. Bényei-Himmer et M. Höhn (Figs 2, 5)
3b  e axis of the in orescence is longer, fruits develop (even) from the lateral umbel .............. 4
4a  e leaves of the ground creeping shoots greatly vary.  e colour of the leaves can be di erent
from bright green to dark green, o en with white veins. Number of leaf lobes can vary between
3–7 and leaf base can be cordate or truncate, with elongate central lobe. Stellate trichomes have
4–10 rays, and multicellular branched trichomes can also appear.  e leaves of the generative
(adult stage) shoots are elongate, oval with a cuneate leaf base.  e length of the in orescence
axis is 6–9 cm long, o en third-order branching, in some case with bracts. Flowering period
lasts from August until October. Fruits diverse with 1–3 seeds.  e protruding discus is fre-
quent. Generative shoots only at elevating age. Leaves do not freeze even during cold winters.
Many cultivars are widely planted. Native diploid taxa .................................. H. helix L. (Fig. 8B)
Triploids considered most probably hybrids between H. helix and H. hibernica.  ese tri-
ploid specimens were previously treated as H. helix or H. hibernica and classi ed among
cultivated ivy varieties.
aa Leaves are triangular, dark green with white veins ...........................................................................
..................................................................... Hedera × schmidtii M. Bényei-Himmer (Figs 12, 13)
bb Leaves are dark green to black with light green veins having 5 lobes ............................................
............................................ Hedera × soroksarensis M. Bényei-Himmer et M. Höhn (Fig. 9, 12)
4b  e leaves of the ground creeping shoots have 5–7 or more equally sized lobes. Leaves are
light green.  e vertically emerging shoots have leaves of 8 cm or larger. Leaf lobes can ap-
pear even on the in orescence carrying shoots (we met this just few years ago on a  ourishing
individual). Native species of the Azores, planted as a perennial in horticultural gardens ........
.......................................................................................................................................H. azorica Carr.
5a Broken shoots are fragrant. Leaves are not lobed or not palmately lobed, with dentate mar-
gins ...........................................................................................................................................................6
5b Broken shoots are fragrant or not. Leaves are palmately lobed or triangular .............................7
6a Leaves are pinnately and slightly lobed, light greyish green, 7–10 cm long.  e adult form of
leaves is narrow lanceolate and the colour of the fruits is orange ................ H. nepalensis Koch
6b Leaves are not lobed, large up to 10–15 cm and skin-like with cordate base. Fruits are black.
(Leaf margin is dentate, o en 12–18 cm in size. Fast growing cultivar: var. dentata. Variegated
leaf cultivars are o en planted) . ......................................................... H. colchica (K . Koch) Koch
7a Leaves are small 2–4 cm long, slightly lobed with truncate base. Flat scale-like (squamiform)
trichomes, upright emerging hairbundle trichomes are also present on the leaves. In Hungary
found only in botanic gardens ................................................................... H. rhombea (Miq ) Bean
7b Leaves are larger ................................................................................................................................... 8

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 249
Studia bot. hung. 48(2), 2017
8a Leaves are without lobes, and the blade is elongate triangular or slightly lobed. Colour bright
green, 10–12 cm long (subsp. cypria).  e leaf blade is greyish around the veins. Shoots are
o en vertically climbing .................................................................. Hedera pastuchoii Woronow
8b Leaves are three or  ve lobed and green or magenta ..................................................................... 9
9a Leaves are  ve-lobed with emerald colour, shoots are magenta. Strong growing capacity.
(Develops  owers and fruits in Hungary, on mild winters it is winter-hardy) .............................
..................................................................................................................... H. maroccana McAllister
9b Leaves are elongate triangular-shaped or with three lobes ........................................................ 10
10a Leaves are acuminate, 3 lobed (with pointed tip), leaf blades are longer than their width, leaf
bases are rounded.  e leaf blade is green with reddish veins. Strong growing and slightly
frost tolerant species. Earlier sold and distributed as H. canariensis, but this species is d i erent
in morphology and ploidy.  e ‘Gloire de Marengo’ is a well-known cultivar, which is planted
in open  eld as well on frost protected areas ............................................ H. algeriensis Hibberd
10b Leaves are barely lobed, mid-sized and wider than longer, pale green. Slow growing and frost
sensitive .............................................................................................................. H. canariensis Willd.
CONCLUSIONS
Our analysis based on cytological, morphological study and ecological ob-
servations indicates that H. crebrescens can be considered a distinct taxon among
the diploid ivies.
We emphasize that this Hedera taxon, spreading in Hungary and formerly
treated as H. hibernica is not identical with the tetraploid taxon. H. hibernica in
Hungary has its  owering period later than H. helix or H. crebrescens, and the
late fall frosts damage the seed development and reproductive potential of H.
hibernica. Moreover, based on S (2004), H. crebrescens is not identi-
cal with H. hibernica, the “noxious invasive ivy” taxon spreading in the USA.
Based on higher viable seed production, successful propagation by birds, and its
high germination rate, we consider H. crebrescens as the most invasive ivy taxon
in Hungary and most probably in the surrounding countries. We consider that
most of the recently reported new occurrences of H. helix by the Atlas of Flora
Hungariae from the lowland in Hungary refer to H. crebrescens (B and
K 2015: 65). In the case of the triploids identi ed in this study, further
study is needed to elucidate the parents.
All the taxa that we have studied exhibited stellate trichome types. However,
trichome morphology should not be considered a taxonomically de nitive crite-
rion in Hedera, as suggested by K (1977), because stellate trichomes
with four rays emerging in two directions (bifurcate) are present in many Hedera
taxa. Moreover, when the leaves begin to age, these bifurcate stellate trichomes
are able to develop new rays and will become multiangulate.
Studies that include species from the eastern part of the distribution range
of the Hedera genus, the Caucasus, and the Far East, formerly mentioned by P-
  (1951), are necessary in order to explore ivy diversity and relationships.

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
250
Studia bot. hung. 48(2), 2017
***
Acknowledgements: Authors are grateful to Zoltán Barina for nomenclatural advice and to
Hugh McAllister for the useful comments and suggestions.
Összefoglaló: Az északi mérsékelt égövi, eurázsiai elterjedésű Hedera nemzetség mintegy 12
faja közül csak a diploid Hedera helix L. tekinthető honosnak a Kárpát-medencében. Kertészeti
kultúrából azonban számos faj és azok hibridje, kultúrváltozata ismert. Leggyakrabban találkoz-
hatunk a bizonytalan származású ír borostyánnal, a H. hibernica-val, amely egy tetraploid taxon. A
különböző ploidia-típusok közötti egyrészt spontán másrészt mesterséges hibridizáció eredménye-
képpen a borostyánok között morfológiailag változatos génanyag jött létre, mely a taxonok elkü-
lönítését megnehezítette. Morfológiai és citometriai vizsgálatainkkal bizonyítottuk, hogy egy ko-
rábban H. hibernica-ként számon tartott taxon diploid és nem azonos a szintén diploid, honos H.
helix fajjal. Ez a taxon félkultúr és kultúr területeken, városi környezetben, vasutak mentén és fo-
lyópartokon spontán módon terjed. Összehasonlító morfológiai, fenológiai és kromoszóma vizs-
gálatok eredményei alapján ezt az új d iploid taxont H. crebrescens néven írjuk le. Ez a taxon erőteljes
növekedésű, mind vegetatív, mind pedig generatív tulajdonságaiban elkülöníthető a H. helix-től és
a H. hibernica-tól is. Terjedési erélyét segíti a nagy maghozam, a magok madarak általi sikeres ter-
jesztése, a magas csírázási arány és gyors növekedése által a honos borostyán élőhelyét veszélyezteti.
A Hedera nemzetségből korábban ismert di-, tetra-, hexa- és oktoploid taxonok mellett faj-
tagyűjteményekben szereplő és spontán előfordulású egyedek átfogó vizsgálatával először azonosí-
tottunk triploid taxonokat. Ezen triploidokat hibrid eredetű fajként tartjuk számon, közöljük a le-
írást a környezeti igény és kertészeti jelentőség bemutatásával.
REFERENCES
A, J. and W, J. (2002): A morphometric analysis of Hedera L. (the ivy genus, Aralia-
ceae) and its taxonomic implications. – Adansonia 24: 197–212.
A, J. and W, J. (2003): Evolution of Hedera (the ivy genus, Araliaceae): insights from
chloroplast DNA data. Int. Plant Sci. 164: 593–602. https://doi.org/10.1086/375423
B, D. and K, G. (eds) (2015): Distribution atlas of vascular plants of Hungary. (Magyar-
ország edényes növényfajainak elterjedési atlasza). – University of West Hungary, Sopron,
330 pp.
B, W. J. (1914): Trees and shrubs hardy in the British Isles. I. – John Murray publishing, London,
pp. 607–609.
B-H, M. (1994): A borostyán mint őshonos és kultúrnöény Magyarországon. – Manu-
script, PhD thesis, Univ. Horticult. Industriaeque Aliment.
B H, M. and H, M. (2017): Hedera x soroksarensis. – In: MA, H. A.
and M, R. H. (eds): Hedera: the complete guide.  e Royal Horticultural Society,
London, 401 pp.
B-H, M., B, G., H, M., S, G. and K, E. (2005a): Hedera
fajok és fajták genomméretének meghatározása  ow citométeres vizsgálatokkal. (Ploidy levels of
Hedera species and cultivar determined by  ow-cytometrical study). – XI. Scienti c Days in
Plant Breeding, Hungarian Academy of Sciences (MTA), Budapest, p. 83.
B H, M., H, M., B, G., P, A., K, E., S, G. and
D, T. (2005b): Flow citométeres vizsgálat felhasználhatósága Hedera taxonok genetikai di-
verzitásának és rokonsági kapcsolatainak elemzésében. (Flow cytometry, available for detecting

HEDERA CREBRESCENS AND TRIPLOID IVIES FROM HUNGARY 251
Studia bot. hung. 48(2), 2017
diversity patterns and relationships among di erent Hedera specimens.) – Lippay–Ormos–
Vas Scienti c Conference. Corvinus University of Budapest (BCE), Budapest, pp. 32–33.
B H, M., B, G., H, M., P, A., K, E., S, G. and
L, S. (2006): Honos és kultúr borostyánok diverzitásának és rokonsági kapcso-
latainak elemzése genetikai vizsgálatok eredményeinek a felhasználásával. (Diversity pat-
terns and relationships of di erent native and cultivated ivies based on genetic studies.) –
Kitaibelia 11: 43.
C, A. P. D. (1830): Prodromus systematis naturalis regni vegetabilis: sive enumeratio con-
tracta ordinum generum specierum que plantarum huc usque cognitarum, juxta methodi natu-
ralis normas digesta. – Sociorum Treuttel et Würtz, Paris, pp. 261–265.
C, E. A. (1890): Une Importante Collect ion de Lierres von A. E. Carriere. – Revue Horticole
62: 162–165 pp.
C, M. M., R, S. H., and H, C. W. (2006): Prevalence of di erent hor-
ticultural taxa of ivy (Hedera spp., Araliaceae) in invading populations. – Biol. Inasions 8:
149–157. https://doi.org/10.1007/s10530-004-2424-6
D, J., B, P. and L, S. (1989): Analysis of nuclear DNA content in plant. –
Biol. Plantarum 31: 113–120.
G, L. and V, R. (1992): Dendrológia. – Mezőgazda Kiadó, Budapest, pp. 609–611.
G, A. F., R, T. S. and R, J. (2011): Phylogeny and biogeography of ivies (Hedera
spp., Araliaceae), a polyploid complex of woody vines. – Syst. Bot. 36: 1114–1127.
https://doi.org/10.1600/036364411X605100
G, D. and P, R. J. (2002): Phylogeography of the common ivy (Hedera sp.) in Europe:
genetic di erentiation through space and time. – Mol. Ecol. 11: 1351–1362. https://doi.
org/10.1046/j.1365-294X.2002.01522.x
IBM Corp. (2013): IBM SPSS Statistics for Windows, Version 22.0. – Armonk, NY: IBM Corp.
J, P. (1954): Chromosome numbers in the genus Hedera L. – Hereditas 40: 252–254.
J, H. (1865): Die Ziergehölze der Garten-und Parkanlagen. – Bernhard Fridrich Voigt. Weimar,
250 pp.
K, K. (1869): Dendrologie I. – Erlangen, Berlin, pp. 518–545.
K, E. A., R, V. S., V, S. A. and S, A. B. (2003): Morphological leaf-
variability of West Caucasian Hedera L. (Araliaceae) species. – Wulfenia 10: 51–59.
K, G. (1977): Handbuch der Laubgehölze 2. auf 1. – Von Gerd Krüssmann, Berlin und
Hamburg, Paul Parey, Bd. II, pp. 137–143.
L, L. (1930) Die P anzenareale. Hedera, Taf. I.–IV, Sammlungkartographischer Dar-
stel lungen on Verbreiungsbzirken der lebenden u. fossilen P anzenfamilien. – Von Ludwig
Diels u.a., Jena, pp. 65–68.
L, S., P, I., B, G., H, M. and B H, M. (2007):
Citogenetikai vizsgálatok honos és kultúr borostyánoknál. (Cytological evaluation of natu-
ral and cultivated ivies) – XIII. Scienti c Days in Plant Breeding, Hungarian Academy of
Sciences (MTA), Budapest, p. 122.
L, C. (1753): Species Plantarum. – Laurentius Salvius, Stockholm, 1179 pp.
L, Y., B, W., M, I. and D, R. (2010): Hedera helix as a me-
dicinal plant. – Herba Polonica 56: 83–96.
M, R. H., MA, H. A. and A, J. D. (2017): A summary of hybrids de-
tected in the genus Hedera (Araliaceae) with the provision of three new names. – New J. Bot.
7(1): 2–8. https://doi.org/10.1080/20423489.2017.1344041
MA, H. A. (1981): New work on ivies. – International Dendrological Society Yearbook,
Univ. of Minnesota, pp. 106–109.

BÉNYEI-HIMMER, M., TÓTH, E. GY., LENGYEL, SZ., PINTÉR, I. et al..
252
Studia bot. hung. 48(2), 2017
MA, H. A. and M, R. H. (2017): Hedera: the complete guide. –  e Royal Horti-
cultural Society, London, 401 pp.
MA, H. A . and R, A. (1997): Hedera Linnaeus. – In: C, I., A ,
J. C. M, B, C. D. and E, J. R. (eds):  e European Garden Flora Volume
V. Dicotyledons (Part III.). University Press, Cambridge, pp. 375–380.
M, D. J. (1958): Biological  ora of the British Isles. Hedera helix L. – J. Ecol. 93: 632–648.
P, E. C. A. and K, G. (1864): Arboretum muscaviense. – W. Opetz Com, Gotha,
1470 pp.
P, S. (1974):  e ivy book. – Macmillan, New York, London, 164 pp.
P, A. (1951): Species chinensis generis Hedera L. et earum a nitas. – Not. Syst. (Lenin-
grad) 114: 244–264.
R, P. Q. (1996):  e gardener’s guide to growing ivies. – Timber Press, Portland, Oregon, 160 pp.
R, A., MA, H . A. and M, R. R . (1993): New ivies from the Mediterranean
area and Macaronesia. – Plantsman 15: 115–128
S, C. K. (1912): Illustriertes Handbuch der Laubholzkunde. – G. Fischer Verlag, Jena,
pp. 188–190.
S, E. (1875): Kalt- und Warmhausp anzen, Kunst- und Handelsgartnerei. – 19. Druck
von Anton Renn, Prague, 9 pp.
S, R. (1966): A magyar  óra és vegetáció rendszertani-nöényföldrajzi kézikönyve II. Synopsis syste-
ma tico-geobotanica  orae vegetationisque Hungariae II. – Akadémiai Kiadó, Budapest, 429 pp.
S, R. and J, S. (1951): A magyar nöényvilág kézikönyve. – Akadémiai Kiadó, Budapest,
397 pp.
S, S. M. (2004): Is ivy invasive? What is known about ivy? – Ivy Journal. 30: 5–71.
T, F. (1912): Die Gattung Hedera. – G. Fischer Verlag, Jena, 151 pp.
U, L. and B-H, M. (1999): Escape of Irish ivy (Hedera hibernica (Kirchner)
Bean) as a woody evergreen weed. – Kertészeti és Élelmiszeripari Egyetem közleményei 59:
161–164.
V, V. and V, P. (2010): Quantitative morphology and species delimitation under
the general lineage concept: Optimization for Hedera (Araliaceae). – Amer. J. Bot. 97: 1555–
1573. https://doi.org/10.3732/ajb.1000115
V, P., MA, H. A., M, C., J, S. L., and W, M. J. (1999) Polyploid
speciation in Hedera (Araliaceae): phylogenetic and biogeographic insights based on chro-
mosome counts and ITS sequences. – Plant Syst. Evol. 219: 165–179.
https://doi.org/10.1007/BF00985577
(submitted: 03.11.2017, accepted: 17.03.2017)