Lecanora (Aspicilia) masafuerensis is a species of Xenolecia (Ascomycota, Lecideaceae)

Abstract

The new combination Xenolecia masafuerensis is made for Lecanora masafuerensis, a lichen species known from only two localities on Isla Alejandro Selkirk in the Juan Fernández archipelago, Chile. The species is fully described and illustrated and shown to be morphologically and chemically distinct from the similar X. spadicomma, which is known only from Chile and the Falkland Islands. The typification of X. masafuerensis and its distribution on the islands are also discussed.

Full text

Lecanora (Aspicilia) masafuerensis is a species of Xenolecia
(Ascomycota, Lecideaceae)
Alan M. Fryday*
Abstract. The new combination Xenolecia masafuerensis is made for Lecanora masafue-
rensis, a lichen species known from only two localities on Isla Alejandro Selkirk in the
Juan Fernández archipelago, Chile. The species is fully described and illustrated and shown
to be morphologically and chemically distinct from the similar X. spadicomma, which is
known only from Chile and the Falkland Islands. The typication of X. masafuerensis and
its distribution on the islands are also discussed.
Key words: distribution, endemic species, Juan Fernandez islands, lichenized-fungi, typ-
ication
Introduction
The genus Xenolecia was erected by Hertel (1984) for
the single species X. spadicomma (Nyl.) Hertel (basionym
Lecidea spadicomma Nyl.), which was known only from
the type collection made by R.O. Cunningham from Isla
Wellington in southern Chile in 1868 (Crombie 1876).
Fryday & Thüs (2017) reported additional records of this
species from Los Largos Region, Chile and from sev-
eral localities on the Falkland Islands, and also reported
a second species in the genus, X. cataractarum Fryday,
from Campbell Island New Zealand. Here, a third species
is added to the genus from the Juan Fernandez archipe-
lago, Chile.
The Juan Fernández archipelago is located 650–
830 km o the west coast of Chile at a latitude of ~33.5°S.
It consists of three main islands; Robinson Crusoe Island
(47.9 km2), Alejandro Selkirk Island (49.5 km2) and the
much smaller Santa Clara Island (2.2 km2) (Fig. 1). The
two larger islands were formerly known as Más a Tierra
and Más Afuera, respectively, but their names were
changed in 1966 to promote tourism. The islands have
a rugged, mountainous terrain reaching over 1,250 m
in altitude and experience a subtropical Mediterranean
climate that is moderated by the cold Humboldt Current.
Temperatures show little seasonal variation, daily mean
temperatures ranging from 12.5°C in August to 19.0°C in
February. Average annual precipitation is c 1,000 mm, but
is strongly inuenced by the El Niño–Southern Oscillation
and can vary between ~300 mm/year to over 1,500 mm/
year (Wikipedia 2023). The archipelago became a national
park in 1935 and was designated as a UNESCO Biosphere
Reserve in 1977. It is recognized as one of the most eco-
logically vulnerable ecosystems in the world with a high
level of endemism – the islands are sixty-one times richer
in endemic plant species per square kilometer and thirteen
times greater in endemic bird richness than the Galápagos.
(Island Conservation 2023).
There have been three main expeditions to the Juan
Fernandez archipelago that made significant lichen
collections. The rst was by Carl Skottsberg in 1917,
whose lichen collections were identied and described
by Zahlbruckner (1924), and the second by Hernry
Imshaug in 1965. Imshaug made ~1,600 lichen collec-
tions, which are preserved in the herbarium of Mich-
igan State University (Fryday & Prather 2001), but
never published the results of his investigations. Finally,
Redón & Quilhot (1977) stayed over a month in 1975,
but only some of their results were published. Although
Skottsberg and Imshaug visited both of the main islands,
Redón & Quilhot visited only Isla Robinson Crusoe and
did not visit Isla Alejandro Selkirk. Both Skottsberg and
Imshaug collected specimens of the lichen that is the
subject of this paper.
Materials and methods
Gross morphology was examined under a dissecting micro-
scope and apothecial characteristics by light microscopy
(compound microscope) on hand-cut sections mounted in
water, 10% KOH (K), 50% HNO3 (N) or Lugol’s reagent
(0.15% aqueous IKI). Thallus sections were investigated
in water, K and Lugol’s reagent. Ascospore measurements
Herbarium, Department of Plant Biology, Michigan State University,
East Lansing, Michigan 48824, USA
ORCID: 0000-0002-5310-9232
* Corresponding author e-mail: fryday@msu.edu
ISSN 2544-7459 (print)
ISSN 2657-5000 (online)
Plant and Fungal Systematics 68(2): 382–387, 2023
DOI: https://doi.org/10.35535/pfsyst-2023-0022
Article info
Received: 19 Jun. 2023
Revision received: 21 Aug. 2023
Accepted: 18 Sept. 2023
Published: 29 Dec. 2023
Associate Editor
Christian Printzen
© 2023 W. Szafer Institute of Botany, Polish Academy of Sciences.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/)

A. M. Fryday: Lecanora masafuerensis is a species of Xenolecia 383
are given as (minimum value–) mean ±standard deviation
(–maximum value). Thalline chemistry was investigated
by thin-layer chromatography (solvent C) following the
methods of Orange et al. (2001).
Additional comparative specimens examined.—Xenole-
cia cataractarum: NEW ZEALAND. Campbell Island, around
waterfalls in Dracophyllum scrub on south slope of Mt. Honey,
above Southeast Harbour, 21 January 1970, H.A. Imshaug
47396 (MSC0195380 – holotype).—Xenolecia spadicomma
(selected): CHILE. [XII Región de Magallanes y de la Antár-
tica Chilena, Isla Wellington], Eden Harbour, in the bed of
a stream, April 1868, R.O. Cunningham (BM – holotype; BM,
E – isotypes). FALKLAND ISLANDS. East Falkland: clis on
rock dome at summit of Mt. Kent, 21F VC 2374 [51°42.550′S,
58°0.900′W], 1500 ft. [457.5 m], 1968, H.A. Imshaug 41549
(MSC0011041).
Results
Specimens collected by Imshaug and named as Lecanora
masafuerensis, along with an isotype of that taxon in NY
and a high-resolution image of the holotype in W, were
compared with each other and with specimens of Xenole-
cia spadicomma. This showed that Imshaug’s collections
were correctly identied and that L. masafuerenis and
X. spadicomma were clearly congeneric and very similar
to each other. However, close morphological investigation
and chemical analysis revealed several dierences that
indicated that two distinct taxa were involved. Unfortu-
nately, the most recent collections of L. masafeuerensis
were made in 1965 and so molecular analysis to conrm
this was not a realistic possibility.
Taxonomy
Xenolecia masafuerensis (Zahlbr.) Fryday, comb. nov.
Fig. 2
MycoBank MB 849821
≡ Lecanora (Aspicilia) masafuerensis Zahlbr., in Skotts-
berg, Nat. Hist. Juan Fernandez Easter Isl. Vol. 2 (Bot.) 3(11):
378. 1924.
Type: Chile, Juan Fernández Islands, Más Afuera [Isla Ale-
jandro Selkirk], Quebrada de las Casas, C. & I. Skottsberg s.n.
(W0207554 – holotype, high resolution image seen; BM, GB,
LD, NY!, UPS – isotypes).
Description. Thallus wide spreading, euse, creamy-yel-
low to pale grey. ~0.3–0.5 mm thick, smooth cracked-are-
olate, areoles rhomboid, at to slightly convex separated
by ne cracks, 0.4–0.6 mm across. In section a thin
hyaline cortical layer ~20–25 µm thick above a thick
photobiont layer ~200 µm thick that is interrupted by nar-
row bands of medullary tissue 20–25 µm wide; medulla
to 250 µm deep, hyaline above becoming rusty brown
below, slightly I+ mauve (only apparent in section).
Photobiont chlorococcoid, cells thin-walled ~8–15 µm
diam. Apothecia innate, lecideine, often separated from
the thallus by a wide crack, disc dark-brown, mid-brown
when wet, concave, 0.4–0.6 mm across, proper margin
not apparent, but with a section of the thallus adhering
to the disc forming a pseudothalline margin. In section:
proper exciple cupular, dark brown ~10–25 µm wide, but
becoming thinner towards the surface and often visible
only as a narrow band of hyaline, vertically aligned –
hyphae ~5 µm wide. Hymenium 175–200 µm deep, upper
Figure 1. The Juan Fernandez islands; location, position of the two main islands and the two collection sites of Xenolecia masafuerensis (yellow
diamonds).

384 Plant and Fungal Systematics 68(2): 382–387, 2023
Figure 2. Xenolecia masafuerensis (Imshaug 36697 – topotype). A – thallus and apothecia; B – apothecia; C – section of apothecium; D – sec-
tion of exciple; E – pycnidia; F – conidia; G – ascospore in ascus. Scale bars: A = 2 mm; B = 0.5 mm; C = 100 µm; D = 50 µm; E = 1 mm;
F & G = 10 µm.
25–50 µm (epihymenium) with dilute brown pigment (K–,
N+ yellow), merging imperceptibly into the hypothecium,
which is hyaline above (~75–100 µm) gradually becoming
golden brown below (lowest 75–100 µm), underlain by the
dark proper exciple (25 µm thick); paraphyses sparingly
branched and anastomosing, ~1–1.5 µm thick, widening at
the apex to 2.5–3 µm, rarely with a brown pigmented cap.
Asci Porpidia-type, ±cylindrical ~80–100 × 25–30 µm;

A. M. Fryday: Lecanora masafuerensis is a species of Xenolecia 385
ascospores simple, hyaline, (14.5–)18.9 ± 3.6(–22) ×
(6.5–)9.3 ± 1.7(–12) µm, l/b ratio (1.5–)2.1 ± 0.4(–2.6);
n = 38, spore wall 1–1.5 µm thick, perispore not apparent.
Conidiomata pycnidia, frequent, especially along margins
of adjacent thalli, pale brown, immersed, ~0.05 mm diam.;
conidia short liform, 10–15 × 1 µm.
Chemistry. All spot tests negative; 2’-O-methylperlatolic
acid, conuentic acid, ±?anziaic acid by tlc (Fig. 3).
Discussion. The genus Xenolecia is characterized by
having Porpidia-type asci, innate (aspicilioid) apothecia
with a brown disc and abundant pycnidia containing li-
form conidia (Hertel 1984). All three described species
occur in damp habitats subject to periodic inundation –
most often on rocks in or beside streams (Fryday & Thüs
2017). Fryday et al. (2021) suggested that L. masafue-
rensis was probably a synonym of X. spadicomma, but
closer examination has shown a number of dierences:
X. masafuerensis has smaller apothecia (0.5–2.2 mm diam.
in X. spadicomma) and ascospores (mean 23.0 × 10.7 µm
in X. spadicomma) and a ±hyaline hypothecium (dark
brown in X. spadicomma) suggesting it was a distinct
species. Labels on the Imshaug collections also indicated
that the species contained an unknown substance giving
crystals resembling those of cryptochlorophaeic acid in
GE (1:3 glycerine: glacial acetic acid). Thin layer chro-
matography of X. masafuerensis revealed the presence
of 2’-O-methylperlatolic and conuentic acids as major
substances, with an additional substance giving a green
spot at Rf 4 under UV light after charring in solvent C
(possibly anziaic acid) also being detected in one speci-
men. This contrasts with X. spadicomma, which has only
conuentic acid as a major substance with 2’-O-meth-
ylperlatolic acid and 2’-O-methylmicrophyllinic acid
as minor substances (Fig. 3). These results indicate that
X. masafuerensis and X. spadicomma contain dierent
chemosyndromes: the conuentic acid chemosyndrome
in X. spadicomma, and the 2’-O-methylperlatolic acid
chemosyndrome in X. masafuerensis (Gowan 1989), pro-
viding further evidence that X. masafuerensis should be
recognized as a distinct species. Both species are clearly
distinguished from the third species in the genus, X. cata-
ractarum, the thallus of which contains norstictic acid,
giving a bright red reaction with K (needle-shaped crystals
in section), the other two species being K–.
Typication. Zahlbruckner (1924) gives the type local-
ity of Lecanora masafuerensis as “Chile: Masafuera,
Quebrada de las Casas, bei 450 m, auf vulcanischem
Gestein (C. & I. Skottsberg)”. There is a specimen in the
Naturhistorisches Museum Wien (W), which is where
Zahlbruckner was based, labeled “Typus” and “spec.
orig.”, and is also annotated “Juan Fernandez, Masafuera,
in Quebrada de las Casas, leg. C. & I. Skottsberg”, but no
altitude or date of collection are given (Fig. 4). There are
also collections of Lecanora masafuerensis collected by
C. & I. Skottsberg from Quebrada de las Casas in several
Figure 3. Thin layer chromatography plate under natural (left) and UV light (right). ln 6 Porpidia cinereoatra (McCarthy 3570): conuentic acid;
ln 7, Xenolecia masafuerensis (Imshaug 36704); ln 8, X. spadicomma (Imshaug 41549); ln 9 X. masafuerensis (Imshaug 36872); ln 10 control:
norstictic acid, zeorin, atranorin.

386 Plant and Fungal Systematics 68(2): 382–387, 2023
other herbaria (BM, GB, LD, NY, UPS (2)) that have
labels similar to each other, but dierent to that of the
collection in W. These labels are all headed “SVENSKA
PACIFICEXPEDITION 1916–17” and appear to have
been written by a dierent person than annotated the
specimen in W (presumably Zahlbruckner) and spell the
locality “Zuebrada de las Casas”. These labels also usually
include a date of collection “10/3 1917” and are annotated
“Det. A. Zahlbr.” (Fig. 5). Two, in GB and UPS, have
the elevation given as 150 m but none have the elevation
given as 450 m, which is that given in the protologue. The
elevation given in the protologue is probably a transcrip-
tion error as it is unlikely that the Skottsbergs reached
that altitude on the Island (from his eld books it is clear
that Imshaug certainly didn’t get higher than ~200 m).
These collections and the specimen in W are all from
the same locality and it is safe to assume that they were
all collected on the same date and, therefore, constitute
a “single gathering” (ICNafp Art 8.2: footnote). Because
the collection in W is housed in the herbarium where the
describing author worked and is clearly labeled “Typus”
and “spec. orig” is should be regarded as the holotype,
with the other collections being isotypes.
Imshaug collections. Imshaug’s eld books are pre-
served in MSC. For 27 November 1965, the day he landed
on Más Afuera) he wrote:
Base camp elevation reads c. 400 ft., all other readings of
27 Nov, based on this. On this day went up Quebrada Casas
to point where waterfalls prevented further travel. Collected
from this point back to Base Camp.
In his account of the expedition Meyer (1966) writes
that “A suitable camping site was found in Q. de las
Casas along the stream about a quarter of a mile from the
settlement.”, which would put the base camp at ~275 ft.
(~85 m). At this altitude the Quebrada is relatively broad,
whereas at 400 ft. (~120 m) a further ¼ mile (~400 m)
inland up the Quebrada, it is narrow and there is no suit-
able place for a large group to camp. We must assume,
therefore, that, as he implies, Imshaug had not recalibrated
his altimeter on landing on Más Afuera and it is necessary
to subtract ~125 ft. (~40 m) from his readings for that day.
All three collections of X. masafuerensis from Que-
brada de las Casas (Fig. 1) were collected from Imshaug’s
rst collection site for that day, of which he writes:
At 650 ft. canyon very narrow and walls and base rocks
covered with bryophytes. lmy ferns and Gunnera. Very
few lichens except on large rocks in stream.
Imshaug then gives separate entries for collections
at 600 ft, 550 ft. and 450 ft., but X. masafuerensis was
not collected at these lower locations. This means that
X. masafuerensis would have been collected between
475–525 ft. (145–195 m a.s.l.).
Two days later (29th November) Imshaug collected in
Quebrada de las Vacas, (Fig. 1) ~1.5 km south of Que-
brada de las Casas. In his eld book he wrote:
At two waterfalls in valley (elev. 100 ft.). Valley is a narrow
gorge. Collections mainly from large rocks at least partially
inundated after rains.
Xenolecia masafuerensis was collected at this site, but
although Imshaug then gives separate entries for collec-
tions up to 650 ft. (~200 m), there are no collections of
X. masafuerensis from these higher locations.
Distribution. The two known localities of Xenolecia
masafuerensis are ~1.5 km apart. In Quebrada de las
Casas, X. masafuerensis was collected only above 145 m
a.s.l., whereas in Quebrada de las Vacas it was collected
only at ~30 m a.s.l. As these were the altitudes at which
Imshaug started collecting, it is possible that X. masa-
fuerensis was present at the other altitudes but was not
collected. Also, it is possible that, because these were
the rst two sites where he collected on Juan Fernandez,
X. masafuerensis may have been present elsewhere but
not collected because he had already recorded it from the
islands. However, Imshaug was a very thorough collector
and made ~1,600 lichen collections on the archipelago
(Fryday & Prather 2001), so it seems unlikely that he
would not have recorded the species’ presence at other
localities if it was there – especially when he visited the
other main island of the group, Isla Robinson Crusoe (Más
a Tierra). It is also perhaps signicant that the species
was not recorded by Redón & Quilhot (1977), because
they did not visit Isla Alejandro Selkirk, their collections
being conned to Isla Robinson Crusoe.
Figure 4. Xenolecia masafuerensis. Holotype (W; https://w.jacq.org/
W0207554).
Figure 5. Xenolecia masafuerensis. Isotype label (BM).

A. M. Fryday: Lecanora masafuerensis is a species of Xenolecia 387
Other specimens examined. CHILE. Juan Fernandez, Más
Afuera [Isla Alejandro Selkirk], Quebrada de las Casas, narrow
section, [c. –33.765°S, –80.768°W], with abundant bryophytes,
lmy ferns and Gunnera, 200 m, 27 Nov. 1965, H.A. Imshaug
36697 (MSC, UMCE), 36698 (MSC, HO), 36704 (MSC, LD,
E, M); ibid., Quebrada de las Vacas, near two waterfalls of
stream in narrow section of canyon, [c. 33.775°S, –80.758°W],
100 m, 29 Nov. 1965, H.A. Imshaug 36869 (MIN, MSC), 36972
(MSC, NY, UPS).
Conclusion
Seventy percent of the vascular plants of Juan Fernández
are endemic to the archipelago (Meyer 1966), so it is
not surprising to nd a lichen that also occurs nowhere
else. Xenolecia masafuerensis was recorded by Skottsberg
only at 150 m a.s.l. in Quebrada de las Casas and by
Imshaug between 145 and 195 m a.s.l. at the same locality
and at ~30 m a.s.l. in the nearby Quebrada de las Vacas
(Fig. 1). Both collectors made numerous collections of
the species so it must have been quite frequent. It appears
that X. masafuerensis is a narrow endemic known from
only a small area of one island of the Juan Fernández
archipelago where it appears to be quite frequent – or at
least it was 60 years ago! The sites are remote and rarely
visited so the species is probably not in any danger, but
it would be good to know its current status and monitor
any changes that may occur in the future.
Acknowledgements
Jack Elix (Canberra) is thanked for assistance with identifying
the TLC products. I also thank the curators and other personnel
of the herbaria GB, UPS & W for responding positively to
my requests for images of the specimens in their care, to the
curators of NY for the loan of their isotype specimen and the
curators of BM and W for permission to reproduce images of
their collections. I also thank an anonymous reviewer for details
of the visit by Redón & Quilhot to Robinson Crusoe Island, of
which I was previously unaware.
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