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Endemic families of Madagascar. IX. A new littoral forest species of Schizolaena (Sarcolaenaceae)

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Porter P. Lowry II at Missouri Botanical Garden
Porter P. Lowry II
David Rabehevitra at Royal Botanic Gardens, Kew
David Rabehevitra
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Schizolaena raymondii is described from a single stand of low-elevation litto- ral forest in NE Madagascar, one of the island's fl oristically richest and most highly threatened ecosystems. Th e new species is illustrated and compared to other members of the genus; it most closely resembles three congeners with which it shares thick leaves with a rounded to acute apex, but is distinguished by having longer petals and a unique combination of leaf blade and peduncle lengths. Schizolaena raymondii is assigned a preliminary conservation status of Critically Endangered using the IUCN Red List criteria.
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149
ADANSONIA, sér. 3 • 2006 • 28 (1)
© Publications Scientifi ques du Muséum national d’Histoire naturelle, Paris. www.adansonia.com
Endemic Families of Madagascar. IX.
A new littoral forest species of Schizolaena
(Sarcolaenaceae)
Porter P. LOWRY II
Missouri Botanical Garden, P.O. Box 299, St. Louis, MO, 63166-0299 (USA)
pete.lowry@mobot.org
and Département Systématique et Évolution (USM 602),
Muséum national d’Histoire naturelle,
case postale 39, 57 rue Cuvier, F-75231 Paris cedex 05 (France)
lowry@mnhn.fr
David RABEHEVITRA
Missouri Botanical Garden, Madagascar Research and Conservation Program,
B.P. 3391, Antananarivo 101 (Madagascar)
david.rabehevitra@mobot-mg.org
KEY WORDS
Sarcolaenaceae,
Schizolaena,
conservation,
Madagascar,
littoral forest,
new species.
Lowry II P. P. & Rabehevitra D. 2006. — Endemic Families of Madagascar. IX. A new littoral
forest species of Schizolaena (Sarcolaenaceae). Adansonia, sér. 3, 28 (1) : 149-153.
ABSTRACT
Schizolaena raymondii is described from a single stand of low-elevation litto-
ral forest in NE Madagascar, one of the island’s fl oristically richest and most
highly threatened ecosystems.  e new species is illustrated and compared to
other members of the genus; it most closely resembles three congeners with
which it shares thick leaves with a rounded to acute apex, but is distinguished
by having longer petals and a unique combination of leaf blade and peduncle
lengths. Schizolaena raymondii is assigned a preliminary conservation status of
Critically Endangered using the IUCN Red List criteria.
150 ADANSONIA, sér. 3 • 2006 • 28 (1)
Lowry II P. P. & Rabehevitra D.
INTRODUCTION
e east coast of Madagascar is dotted with a se-
ries of small, isolated remnant patches of humid
evergreen forest growing on unconsolidated sand.
Restricted to a narrow strip that averages only a
few kilometers in width, these littoral forests are
estimated to contain 1550 species of vascular plants
(Consiglio et al. in press; see also http://www.mobot.
org/MOBOT/ research/littoral), representing well
over 10% of the entire Malagasy fl ora, currently esti-
mated to comprise c. 12 000-13 000 species (Schatz
2001; Goodman & Benstead 2005) or perhaps as
many as 14 000 species (Phillipson et al. 2006). In
the past, littoral forest probably stretched almost
continuously for nearly 1600 km, from SE of An-
tsiranana in the north to just beyond Tolagnaro in
the south, spanning nearly 12° of latitude. Today,
however, this distinctive, specialized vegetation has
been dramatically reduced in extent, and now totals
an estimated 47 900 ha (0.8% of the total land area
of Madagascar, and just 10% of the formation’s
original extent), of which the largest stand covers
only about 2650 ha.
During the last four years, we have collaborated
with a team of colleagues to conduct an exten-
sive inventory of the plants occurring in nine of
the largest and best-preserved stands of littoral
forest.  e project aims to compile a compre-
hensive checklist of the vascular plant species in
this highly threatened ecosystem, document the
current extent of littoral forests, and formulate
recommendations for conservation measures.
To date our team has made about 9000 collec-
tions, including many that appear to represent
new taxa. Here we describe a distinctive new
species of Schizolaena ouars, the largest genus
of Sarcolaenaceae, Madagascar’s most speciose
endemic family. Our novelty adds to the 18 spe-
cies of Schizolaena recently recognized by Lowry
et al. (1999), six of which also occur in eastern
littoral forest.
SYSTEMATICS
Schizolaena raymondii
Lowry & Rabehevitra, sp. nov.
(Fig. 1)
Diff ert a Schizolaena elongata, S. hystrice et S. tam-
poketsana petalis longioribus (7-8 mm) et combinatione
foliorum 7-7.5 cm longorum cum pedunculis (4-)7-11 mm
longis.
T
YPUS
. — Madagascar. Prov. Antsiranana, Fivondronana
Vohemar, Fokontany Manakana, Forêt d’Ambondrobe,
13°43’14”S, 50°05’59”E, [c. 25-50 m], 26.X.2002, fr.,
Rabevohitra, McPherson, Rabenantoandro & Ranarivelo
4217 (holo-, MO!; iso-, G!, K!, P!, TEF[2]!).
RÉSUMÉ
Familles endémiques de Madagascar. IX. Une nouvelle espèce de Schizolaena (Sar-
colaenaceae) de la forêt littorale.
Schizolaena raymondii est décrite ; elle est connue d’une seule parcelle de forêt
littorale de basse altitude dans le NE de Madagascar, un des écosystèmes mal-
gaches fl oristiquement les plus riches mais aussi parmi les plus menacés. Une
illustration est fournie et la nouvelle espèce est comparée aux autres membres du
genre. Elle se rapproche en particulier de trois autres espèces dont elle partage
les feuilles épaisses à apex arrondi à aigu, mais dont elle se distingue par des
pétales plus longs et une combinaison caractéristique de longueurs de limbes
foliaires et de pédoncules. Une analyse préliminaire du statut de conservation
selon les critères des Listes Rouges de l’UICN indique que S. raymondii est à
rattacher à la catégorie « en danger critique d’extinction ».
MOTS CLÉS
Sarcolaenaceae,
Schizolaena,
conservation,
Madagascar,
forêt littorale,
espèce nouvelle.
151
New species of Schizolaena (Sarcolaenaceae)
ADANSONIA, sér. 3 • 2006 • 28 (1)
FIG. 1. — Schizolaena raymondii Lowry & Rabehevitra, sp. nov.: A, fruiting branch; B, fl ower buds; C, fl ower; D, mature fruit surrounded
by involucre. A, B, D, Rabevohitra et al. 4217; C, Rabehevitra et al. 319. Scale bars: A, 1 cm; B, C, 8 mm; D, 5 mm.
AD
B
B, C
C
PARATYPES. — Madagascar. Prov. Antsiranana, Fivon-
dronana Vohemar, Fokontany Manakana, Forêt
d’Ambondrobe, 13°43’06”S, 50°05’52”E, 53 m,
15.VII.2003, fl ., Rabehevitra, Razakamalala & Rakoto-
mamonjy 319 (G, K, MO[2], P, TEF, US, WAG). — Same
locality, 13°42’46”S, 50°05’25”E, 20.V.2004, bud, fl .,
y.fr., Rabehevitra & Razakamalala 1013 (K, MO, P,
TEF[2]).
DESCRIPTION
Trees c. 8-14 m tall. Twigs with scattered stellate indu-
mentum. Leaves evenly distributed along branchlets,
blades elliptic to slightly obovate, greenish-brown
above, khaki green below (in dry material), sub-
coriaceous, 3-7.5 × 2-4.4 cm, with minute stellate
indumentum below, more prominent on the midrib,
152 ADANSONIA, sér. 3 • 2006 • 28 (1)
Lowry II P. P. & Rabehevitra D.
TABLE 1. — Characters distinguishing Schizolaena raymondii Lowry & Rabehevitra from the three species it most closely resembles.
S. raymondii S. elongata S. hystrix S. tampoketsana
Petal length (mm) 7(-8) 5-6 4 5-6
Length of largest
leaf blade (cm)
7-7.5 (3.5-)4-5.5 8.5-10.5 5-6.5
Peduncle length (mm) (4-)7-11 4-12 1-3(-5) 1-2
Calyx indumentum
(abaxial surface)
short stellate-villous tufted papillose stellate evenly sericeous
stellate
evenly sericeous
stellate
Distribution Manakana Masoala National Park
to Fort Dauphin
Marojejy National Park
to Tsianivoho
Andranofeno Sud
glabrous above, apex acute, often folded in pressed
material, margin entire, minutely thickened, revo-
lute (sometimes weakly so), base broadly cuneate or
rounded to truncate or slightly subcordate, venation
brochidodromous, with 8-11 pairs of alternate to
subopposite secondary veins joined by rounded arches,
midrib weakly channeled above, raised below; petiole
4-6(-7) mm long, with moderate to dense stellate
indumentum; stipules unknown, caducous, leaving
small scars. Infl orescences axillary and terminal sparse-
ly-branched cymes, usually several borne together
toward branch tips, each (1-)2-12-fl owered, primary
axis 12-37 mm long, densely papillose stellate-stri-
gose, most trichomes with a central branch much
longer than the others, bracts unknown, caducous,
peduncles (ultimate axes borne below the involucre)
(4-)7-11mm long, densely papillose stellate-strigose,
involucre in fl ower with 5 irregular lobes, densely
papillose stellate-strigose, containing 1 or 2 sessile
fl owers; sepals 3, imbricate, broadly ovate, adaxially
concave, 4-5 mm long at anthesis, minutely villous
on adaxial surface (glabrous towards the base), with
dense, short stellate-villous indumentum on abaxial
surface, apex rounded, margins entire; petals 5, el-
liptic to ovate, slightly succulent in fresh material,
chartaceous when dry, 7(-8) × 3.5(-5) mm, glabrous,
with minute white striations (in dry material), apex
rounded to broadly acute; stamens c. 80, fi laments
slender, c. 5-7 mm long, glabrous, anthers ellipsoid,
0.3-0.4 mm long; ovary broadly depressed ovoid in
fresh material, to depressed globose in dry material,
densely woolly tomentose, 3-locular; style cylindrical,
curved and S-shaped at anthesis, c. 2.5-3 mm long,
stigma terminal, circular, glabrous. Fruit subglobose,
14-16 mm in diam., with dense stellate indumen-
tum, most trichomes with the central branch much
longer than the others, capsule dehiscent by 3 lon-
gitudinal sutures, exocarp cartilaginous, rugose, dry
sepals and fi laments persistent; involucre expanded,
broadly cupulate to funnelform, fl eshy, reddish pur-
ple in fresh material, 20-25 × 7-12 mm at maturity,
abaxial surface sparsely stellate pubescent, adaxial
surface moderately to densely stellate pubescent,
with 5 broadly ovate to narrowly elliptic, unequal
lobes divided 1/2-2/3 of the way to the base, each
lobe with 8-10(-12) narrowly triangular to elliptical
(rarely lanceolate), sometimes bifi d to dentate teeth,
each 2-5 mm long; seeds 1 per locule, ovoid, dark
brown, 5-7 mm long, 3-5 mm in diam., moderately
to densely covered with small, fl eshy, round to el-
liptic globules, slightly raised from surface when
fresh, shrinking and plane with surface when dry,
hylum depressed concave.
REMARKS
Schizolaena raymondii is locally abundant but re-
stricted to a single locality in NE Madagascar,
the Ambondrobe littoral forest, a well preserved
2650 ha stand situated c. 40 km S of the town of
Vohemar. Using the key provided by Lowry et al.
(1999), both fl owering and fruiting material of
our new species would be identifi ed as belonging
to a group that includes S. elongata, S. hystrix and
S. tampoketsana, all of which share coriaceous or
subcoriaceous leaves with a rounded to acute (but
not acuminate) apex and revolute margins, glabrous
petals, and an involucre that is divided at least half
way to the base. However, S. raymondii is easily
distinguished from each of these, as summarized
in the Table 1.
153
New species of Schizolaena (Sarcolaenaceae)
ADANSONIA, sér. 3 • 2006 • 28 (1)
VERNACULAR NAME
Voandrozana.
CONSERVATION STATUS
Application of the IUCN (2001) threat criteria sug-
gests that Schizolaena raymondii should be assigned
a preliminary status of Critically Endangered (CR
B1ab2ab) because its Extent of Occurrence is less
than 100 km2, its Area of Occupancy is less than
10 km2, and it occurs at a single unprotected site
where human pressures will likely lead to continued
decline of the only known population.
ETYMOLOGY
e species epithet honors our good friend and col-
league Raymond Rabevohitra, curator of the TEF
herbarium in Antananarivo, who has contributed
greatly to our knowledge of Madagascar’s woody
fl ora, and who played a key role in our study of the
island’s fascinating eastern littoral forests.
Acknowledgements
We wish to thank G. McPherson and H. Van der
Werff for helpful comments and assistance with the
Latin diagnosis, and R. Lala for the fi ne illustra-
tion. Field work was conducted under collaborative
agreements between the Missouri Botanical Garden
and the Parc botanique et zoologique de Tsimbazaza
and the Direction de la Recherche forestière et pis-
cicole, FOFIFA, Antananarivo, Madagascar. We
gratefully acknowledge courtesies extended by the
Government of Madagascar (Direction générale de
la Gestion des Ressources forestières).  is research
was conducted with support from U.S. National
Science Foundation grant DEB-0102727 (PPL
as Co-PI) and from the John D. and Catherine
T. MacArthur Foundation, LWO Inc., and the
National Geographic Society.
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GOODMAN S. M. & BENSTEAD J. P. 2005. — Updated
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IUCN 2001. — IUCN Red List Categories and Criteria:
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Submitted on 19 July 2005;
accepted on 21 October 2005.
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Madagascar is renowned for its impressive species richness and high level of endemism, which led to the island being recognized as one of the world’s most important biodiversity hotspots. As in many other regions, Madagascar’s biodiversity is highly threatened by unsustainable anthropogenic disturbance, leading to widespread habitat loss and degradation. Although the country has significantly expanded its network of protected areas (PAs), current protocols for identifying priority areas are based on traditional measures that could fail to ensure maximal inclusion of the country’s biodiversity. In this study, we use Madagascar’s largest endemic plant family, Sarcolaenaceae, as a model to identify areas with high diversity and to explore the potential conservation importance of these areas. Using phylogenetic information and species distribution data, we employ three metrics to study geographic patterns of diversity: species richness, Phylogenetic Diversity (PD) and Mean Phylogenetic Diversity (MPD). The distributions of species richness and PD show considerable spatial congruence, with the highest values found in a narrow localized region in the central-northern portion of the eastern humid forest. MPD is comparatively uniform spatially, suggesting that the balanced nature of the phylogenetic tree plays a role in the observed congruence between PD and species richness. The current network of PAs includes a large part of the family’s biodiversity, and three PAs (Ankeniheny Zahamena Forest Corridor, the Bongolava Forest Corridor and the Itremo Massif) together contain almost 85 % of the PD. Our results suggest that PD could be a valuable source of complementary information for determining the contribution of Madagascar’s existing network of PAs toward protecting the country’s biodiversity and for identifying priority areas for the establishment of new parks and reserves.
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... Over the last decade and a half each of the ten genera comprising Madagascar's largest endemic family, Sarcolaenaceae, has been the subject of a synoptic revision, which collectively provide an updated taxonomic treatment of the family, including the description of 29 new species (HONG-WA, 2009 ;LOWRY & al., 1999LOWRY & al., , 2000LOWRY & al., , 2002RANDRIANASOLO & MILLER, 1994SCHATZ & al., 2000SCHATZ & al., , 2001. Moreover, two additional species of Schizolaena Thouars have since been described (LOWRY & RABEHEVITRA, 2006 ;RABEHEVITRA & LOWRY, 2009), largely based on material collected during recent botanical inventory work, bringing the total number of recognized species from the 33 treated in the "Flore de Madagascar et des Comores" (CAVACO, 1952) to a total of 74 (MADAGASCAR CATALOGUE, 2014). Further exploration, especially in areas that have previously received little or no attention, has continued to yield a wealth of new discoveries from throughout Madagascar. ...
Endemic Families of Madagascar. XIII. New, Restricted Range Species of Eremolaena Baill. and Schizolaena Thouars (Sarcolaenaceae)
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Full-text available
  • Dec 2014
Lowry II, P. P., L. Nusbaumer, A. Randrianasolo, G. E. Schatz & C. Hong-Wa (2014). Endemic Families of Madagascar. XIII. New, restricted range species of Eremolaena Baill. and Schizolaena Thouars (Sarcolaenaceae). Candollea 69: 183–193. In English, French and English abstracts. One new species of Eremolaena Baill. and two new species of Schizolaena Thouars (belonging to the family Sarcolaenaceae) are described, illustrated and compared with the members of their respective genera they most closely resemble. Eremolaena darainensis Nusb. & Lowry is similar to Eremolaena rotundifolia (F. Gérard) Danguy but differs from it by features of the indument on the leaves and the sepals, and occurs only in the Loky-Manambato (Daraina) region of far north-eastern Madagascar, where it occurs in semi-deciduous forest on granite. Schizolaena charlotteae Lowry & G. E. Schatz resembles Schizolaena milleri Lowry & al. but is distinguished by differences in sepal indument, petal color, the number of stamens, and the length of the processes borne on the involucre in fruit. Schizolaena parvipetala Randrian. & Hong-Wa is similar to Schizolaena gereaui Lowry & al. but differs by petal size, leaf acumen length, the number of stamens, and the number of flowers per involucre. Both new species of Schizolaena Thouars are only known from lowland humid forest in far south-eastern Madagascar, in the vicinity of the city of Tolagnaro. The distribution and ecology of each species are discussed and preliminary IUCN conservation assessments are provided.
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... Schizolaena was most recently revised by Lowry et al. (1999), who recognized a total of 18 species, to which one novelty has since been added (Lowry & Rabehevitra 2006). Most members of the genus occur in humid to subhumid forest, but one species, S. microphylla H.Perrier, is found in Tapia woodland, growing almost exclusively on quartzite, marble or gneiss outcrops from the Ibity massif south to Ambatofi torahana. ...
Endemic Families of Madagascar. XI. A new critically endangered species of Schizolaena (Sarcolaenaceae) from Tapia woodland in south-central Madagascar
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Full-text available
  • Jan 2011
Familles endémiques de Madagascar. XI. Une nouvelle espèce de Schizolaena (Sarcolaenaceae) en danger critique des bois de Tapia du Centre-Sud de Madagascar. Schizolaena isaloensis Rabehevitra & Lowry est décrite à partir de matériel provenant d'une petite zone fortement dégradée de bois de Tapia, brûlée de façon saisonnière, proche de la limite sud du Parc national de l'Isalo au Centre-Sud de Madagascar. L'espèce est illustrée et des photographies couleurs d'un individu isolé sont présentées. Cette espèce est la plus proche d'un autre membre du genre également des forêts subhumides, S. microphylh H.Perrier, duquel elle diffère par plusieurs caractères foliaires, dont la taille et la forme du limbe, la forme de l'apex, la proéminence de la nervation secondaire sur la face abaxiale et la densité de la pubescence ainsi que par ses fleurs plus petites aux pétales plus étroits. Une analyse préliminaire du statut de conservation selon les critères de la Liste Rouge de l'UICN indique que S. isaloensis est à rattacher à la catégorie « en danger critique d'extinction ».
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Endemic families of Madagascar. XII. Resurrection and taxonomic revision of the genera Mediusella (Cavaco) Hutchinson and Xerochlamys Baker (Sarcolaenaceae)
Article
  • Jan 2011
Familles endémiques de Madagascar. XII. Résurrection et révision taxonomique des genres Mediusella (Cavaco) Hutchinson et Xerochlamys Baker (Sarcolaenaceae). La position de Leptolaena sous-genres Mediusella Cavaco et Xerochlamys (Bak.) Cavaco par rapport à Leptolaena Thouars et Sarcolaena Thouars ainsi que la circonscription des espèces appartenant à ces deux groupes ont été longtemps sujets à controverse. Une récente étude de phylogénie moléculaire suggère l'exclusion de Mediusella et Xerochlamys du genre Leptolaena et une reconsidération de la circonscription générique actuelle au sein du groupe Leptolaena-Sarcolaena-Mediusella-Xerochlamys. Les résultats d'une précédente analyse multivariée sur des caractères morphologiques ont aussi permis de distinguer deux et huit entités respectivement dans Mediusella et Xerochlamys. Ces entités sont reconnues et décrites ci-après comme espèces distinctes les unes des autres. Trois d'entre elles (Xerochlamys coriacea, X. itremoensis et X. undulata) sont nouvelles, et Mediusella arenaria requiert une nouvelle combinaison. Les trois nouvelles espèces se distinguent par leur port, la dimension, la pubescence et la marge de leurs feuilles, et par la structure de leurs inflorescences. Une clé des espèces ainsi que des informations sur la distribution, l'écologie et la phénologie sont présentées. Une évaluation préliminaire du statut de conservation de chaque espèce suivant les critères de l'UICN pour la Liste Rouge indique que six espèces sont en danger (EN), deux autres sont vulnérables (VU), et les deux dernières sont classées dans la catégorie presque menacée (NT) et préoccupation mineure (LC) respectivement.
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Multivariate analyses of morphological characters of Leptolaena Thouars s.l. subgenera Mediusella and Xerochlamys (Sarcolaenaceae)
Article
  • Jul 2008
  • BOT J LINN SOC
Leptolaena Thouars is one of the first described genera within Sarcolaenaceae, but represents the last great species-level taxonomic challenge in this endemic Malagasy plant family. As currently circumscribed, this genus comprises three subgenera, two of which, Mediusella Cavaco and Xerochlamys (Baker) Cavaco, exhibit patterns of morphological variation that have been understood differently and have led to an unstable taxonomy, such that a consensus on the delimitation of species has yet to be reached. Principal component analysis of morphological characters was performed on 211 herbarium specimens in order to evaluate the morphological variation within the two subgenera and to clarify historically problematical species boundaries. The results showed that ten entities could be distinguished on the basis of vegetative, floral, and fruit characters, and that they provide a robust basis for proposing a new species-level taxonomic framework. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157, 559–574.
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Short Communication Updated estimates of biotic diversity and endemism for Madagascar
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Full-text available
  • Jan 2005
  • ORYX
Madagascar is a critical priority for interna- tional conservation efforts, based on almost unparalleled levels of endemism, species diversity, and human threat. Field research conducted over the past two decades has greatly expanded knowledge of the island's biota, making it difficult for any single research team to main- tain up to date estimates of biodiversity and endemism across taxonomic groups. The recent publication of The Natural History of Madagascar, a synthesis by nearly 300 contributors from a wide range of disciplines, provides the means to update these estimates. Here, we summa- rize biodiversity information presented in the volume by providing revised estimates of species richness, endemism, and state of knowledge of a wide variety of taxonomic groups occurring on the island.
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Deforestation and Plant Diversity of Madagascar's Littoral Forests
Article
  • Dec 2006
Few studies have attempted to quantify the reduction or document the floristic composition of forests in Madagascar. Thus, we focused specifically on deforestation and plant diversity in Madagascar's eastern littoral community. We used a data set of approximately 13,500 specimen records compiled from both historical and contemporary collections resulting from recent intensive inventory efforts to enumerate total plant species richness and to analyze the degree of endemism within littoral forests. Change in littoral forest cover from original to current extent was estimated using geographical information systems tools, remote sensing data (satellite imagery and low-elevation digital photography), and environmental data layers. Of the original littoral forest only 10.3% remains in the form of small forest parcels, and only 1.5% of these remaining fragments are included within the existing protected-areas network. Additionally, approximately 13% of Madagascar's total native flora has been recorded from these forests that originally occupied <1% of its total land surface, and over 25% of the 1535 plant species known from littoral forests are endemic to this community. Given the ongoing pressure from human settlement along Madagascar's eastern coast, protection of the remaining forest fragments is critical for their survival. Fifteen of the largest intact littoral forest fragments we identified, collectively representing 41.5% of remaining littoral forest, are among priority sites recommended to the government of Madagascar for plant conservation and incorporation into the protected-areas network.
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A catalogue of the vascular plants of Madagascar
  • Jan 2006
  • B Phillipson P
  • E Schatz G
  • P Lowry Ii P
  • Labat J.-N
PHILLIPSON P. B., SCHATZ G. E., LOWRY II P. P. & LABAT J.-N. 2006. -A catalogue of the vascular plants of Madagascar, in GHAZANFAR S. A. & BEENTJE H. J. (eds), Taxonomy and Ecology of African Plants: their Conservation and Sustainable Use. Proceedings XVIIth AETFAT Congress. Royal Botanic Gardens, Kew.