KEW BULLETIN VOL. 68: 361 Y 364 (2013) DOI 10.1007/S12225-013-9457-X
ISSN: 0075-5974 (print) ISSN: 1874-933X (electronic)
Lespedeza cambodianum (Leguminosae), a new species from Cambodia Rogier P. J. de Kok1 & Nguyen Van Du2
Summary. A new species of Lespedeza Michx. (Leguminosae) from Cambodia is described for the first time. This is the first record of the genus for the country. Key Words. Indo-China, legumes, taxonomy.
Introduction The genus Lespedeza Michx. consist of about 35 species, mostly occurring in China, East Asia and North America (Lewis et al. 2005). The genus is present in Thailand, Laos and Vietnam with only one species (Lespedeza juncea (L. f.) Pers.) (Pramanik & Thothathri 1983; Nguyen Van Thuan et al. 1987; Lock & Heald 1994). The region in general, and Cambodia in particular, is one of the least botanically surveyed countries of the last 200 years (Marsh et al. 2009), which may explain why this eye-catching species has not been previously recorded. In 2009, botanists from the Institute of Ecological and Biological Research, Hanoi, Vietnam, visited Mondulkiri Province in Cambodia. Near the Chey commune in the Chida district, in lowland dry forest dominated by Dipterocarpus species, they found an unknown Leguminosae. Comparison of the collections with the available literature and with the named collections of Lespedeza in the Hanoi Herbarium (NH) and at RBG Kew (K) has proved to be unsuccessful. It seems to have most in common with L. juncea var. sericea (Thunb.) Forbes & Hemsl., which is reported to be the only member of this species complex to be endemic to the tropics and is recorded from Thailand, Peninsular Malaysia, Borneo, the Philippines and northern Australia (Pramanik & Thothathri 1983). However, this form is unknown from Indo-China.
Lespedeza cambodianum V. D. Nguyen sp. nov. Type: Cambodia, Mondulkiri Province, Chida distr., Chey commune, Du, Regalado, Hoe & Sizemore CB-VN 636 (holotype NH!; isotype K!).
http://www.ipni.org/urn:lsid:ipni.org:names:77128856-1 Creeping shrub, c. 1.5 m tall; branches slender, up to 2 m long. Leaves trifoliate, lateral leaflet smaller than central ones; central leaflets elliptical to slightly obovate, 1.7 – 3.5 × 0.5 – 1.2 cm, apex acute, base round, margin entire; upper surface glabrous, lower surface covered with light yellow hairs; veins 5 – 7 pairs, sometimes prominent. Petiole up to 2 cm long, half-terete, sometimes slightly channelled; Stipules present, narrow triangular, 5 – 7 × 1 – 1.5 mm, dark brown, covered by smooth hairs; petiolule with apical swelling, stipulule present. Inflorescence axillary, pseudoumbellate, up to 22 mm long, densely hairy, central peduncle 2 – 3.5 mm long. Calyx 3 – 4 mm long, capitulate, densely hairy; lobes 5, 2 – 3 × 0.6 – 0.9 mm, apex acuminate, 2 back lobes longest. Corolla 5 petals, light yellow; flag spathulate 6.5 – 7 × 3 – 4.3 mm, apex round; wings oblong, 3.8 – 5 × 1.3 – 1.4 mm, apex round; keel 4 – 6.8 × 2 – 2.6, apical part curved upwards; stamens 5; 5.5 – 7 mm long, fused for most of its length, glabrous; anthers 0.5 – 0.6 mm long. Ovaries 1.5 – 1.8 × 1 – 1.2 mm long, with a few hairs; style 5 – 7 mm long, flattened, apex hooked. Fruit 7 – 8.3 × 5.5 – 6 mm, globose, pedunculate; seed 1. Figs 1 and 2. RECOGNITION. Lespedeza cambodianum differs from L.
juncea var. sericea (Thunb.) Forbes & Hemsl. in being a creeping shrub and occurring at low altitude (< 500 m altitude). DISTRIBUTION. Cambodia. SPECIMENS EXAMINED. CAMBODIA. Mondulkiri Province: Chida distr., Chey commune [12°33'30.7''N; 107°21'58.1''E], Du, Regalado, Hoe & Sizemore CB-VN 636 (holotype NH; isotype K).
Accepted for publication 8 May 2013. Published online 7 June 2013 1 Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, UK e-mail:
[email protected] 2 Institute of Ecological and Biological Research, 18 Hoang Quoc Viet, Nghia Do, Cau Giay, Hanoi, Vietnam. e-mail:
[email protected]
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Fig. 1. Lespedeza cambodianum. A habit; B inflorescences; C fruit side view; D standard; E keel; F wing; G stamens; H close-up of ovary; J stigma and ovary; K calyx. From Du et al. CB-VN 636. DRAWN BY MARGARET TEBBS.
© The Board of Trustees of the Royal Botanic Gardens, Kew, 2013
LESPEDEZA CAMBODIANUM (LEGUMINOSAE), NEW SPECIES FROM CAMBODIA
Fig. 2. Habit and flowers of Lespedeza cambodianum.
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PHOTOGRAPH BY NGUYEN VAN DU.
HABITAT. In the shade of broad-leaved trees of dry lowland forest, dominated by the genus Dipterocarpus; 460 m alt. CONSERVATION STATUS. This species is only known from its type specimen and has been recently collected (2009). The forest habitat that it occurs in (lowland dry forest dominated by Dipterocarpus) is threatened, but given the lack of botanical surveys in Cambodia, we do not know if this species is restricted to this habitat or if it has a broader ecological nice. Until more is known about this species an IUCN (2001) rating of DD is proposed. NOTES . This new species is named Lespedeza cambodianum to honour the country where it was first found. Most species of this genus occur at high altitudes, including the only tropical member (L. juncea var. sericea), which is reported to grow only on high table lands throughout SE Asia. The new
species is unique in occurring at relatively low altitudes. This new species is also different from most specimens of L. juncea in being a creeping shrub, while most specimens of L. juncea are erect shrubs. Some specimens of L. juncea are prostrate and recognised as L. juncea var. sericea, but they differ from the new species in having smaller leaflets, flowers and pods (Pramanik & Thothathri 1983).
Acknowledgements The authors would like to thank the Bentham-Moxon Trust for making it possible for author NVD to visit K. We would also like to thank Gwil Lewis and Brian Schrire (K) for access to the Legume collections and for their help in the identification of the specimen and Clare Drinkell from the SE Asian Team for reading the manuscript.
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References IUCN (2001). IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. IUCN, Gland & Cambridge. Lewis, G., Schrire, B., Mackinder, B. & Lock, M. (2005). Legumes of the World. Royal Botanic Gardens, Kew. Lock, J. M. & J. Heald (1994). Legumes of Indo-China. Royal Botanic Gardens, Kew. Marsh, S. T., Brummitt, N. A., de Kok, R. P. J. & Utteridge, T. M. A. (2009). Large-scale patterns of
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Plant diversity and conservation priorities in South East Asia. Blumea 54: 103 – 108. Nguyen Van Thuan, Dy Phon, P. & Niyomdham, C. (1987). Flore du Cambodge, du Laos et du Vietnam 23: Leguminosae (Fabaceae) Papilionoideae. Association de Botanique Tropicale, Paris. Pramanik, A. & Thothathri, K. (1983). Notes on the taxonomy, distribution and ecology of Lespedeza juncea complex with special reference to India. J. Jap. Bot. 58: 331 – 337.
