A New Species of Desmodium (Leguminosae) from Laos

4 Pages·1992·0.48 MB·English

by  Hiroyoshi Ohashi

植物研究雑誌
J. Jpn. Bot.
67: 320-323 (1992)
A New Species of Desmodium (Leguminosae) from Laos
Hiroyoshi OHASHI
Biological Institute，Fa culty of Science，T ohoku University，
Sendai，98 0 JAPAN
ラオス産ヌスビトハギ属の一新種
大橋広好
東北大学理学部生物学教室 980仙台市青葉区荒巻字青葉
(Received on恥1ay25，1 992)
An ew species of Desmodium (Leguminosae)，D . vidalii Ohashi，is described from Laos. It is
classified as am ember of the subgenus Podocarpium.
Desmodium and its related genera are con other new species is described.
田
sidered to be differentiated primarily in South- The name of the new species honors Dr. J. E.
eastern Asia (Ohashi 1973，O hashi et al. 1981)， Vidal of the Laboratoire de Phanerogamie，
because more representatives of the genera closely Museum National d'Histoire Naturelle，Pa ris，in
related to Desmodium and of subgenera of Des- recognition of his distinguished contribution to the
modium occur in this area than in any other areas flora of Indo-China as well as to his taxonomic
in the world. Within Southeastern Asia，B urma， research in the families Leguminosae and
Thailand， Indo-China and Southwest China Rosaceae.
(Yunnan，K wansi and Szechuan) are known to
have more species of Desmodium than Indonesia， Desmodium vidalii Ohashi，sp . nov. (Fig. り1)
Malaysia，M alay Peninsula and South China Species foliis 3-イfoliolatis longi-p
(Hainan). However，D esmodium is apparently less 句(petiol山u1おs9一-15cm lo時n1培gu路s吟)foliolis teぽrmi泊n旧aalislongi-
known in Indo-China than in the other regions r巾h飢achiめb山u1路s(rhachis 3.5一5cm long砂a)a∞c ongeneri-
mentioned above. While preparing at reatment of bus 副di刊versa.Pseudoracemi terminales et axillares，
Desmodium for the “Flore du Cambodge du Laos 30-50 cm longi，lo nge pedunculati，la xi-et pauci-
et du Vietnam"，tw o new species were discovered flori，rh achi pilis rectis et uncinatis vestita. Flores
among unnamed specimens kept in the herbarium fasciculati，2( -3) crescentes; pedicelli tenues，8 -15
of the Laboratoire de Phanerogamie，M useum mml ongi，u t rhachis pilosi. Legumen (valde
National d'Histoire Naturelle (P). One of them was juvenile) stipitatum，3 -4-articulatum，d ense
published in 1990 under the name of Desmodium uncinato-pilosum.
schubertiae (Ohashi 1990). In the present paper the Typus: Laos. Village de Thok，P rovince de
-320ー
December 1992 Journal of Japanese Botany Vol. 67 No. 6 321
Fig. 1. Desmodium vidalii Ohashi (Petelot 4993，T ype).
322 植物研究雑誌第67巻第6号 平成4年12月
Common. Fissures dans les parois verticales d'un Inflorescences terminal and axillary，l ong-
rocher dans une grotte，V ers 160 m. H. Pete!ot pedunculate，30 -50 cm long，si mple or branched，
4993，N ovembre 1930 (p-holo.，ph oto in TUS，A) . pseudoracemose，la x-flowered (with flowers 2(-3)
Perennial herbs 50-60 cm high; stems simple， at each node); rachides rather densely covered with
about 10 cm long，b ent at each node，z igzag， patent，s traight，a nd also hooked hairs; the
striate，c overed with spreading minute hooked peduncles 8-15 cm long. Pedicels 8-15 mml ong，
hairs. Rootstocks more or less woody，th ickened. hairy like the rachis. Primary bracts early
Stipules persistent， triangular-ovate， long deciduous; the secondary bract lanceolate，
acuminate at apex，7 -8 mml ong，3 -4 mmw ide acuminate，a bout 4m ml ong. Bracteoles absent.
near base，sc ariose，st riate，gl abrous inside，wi th Calyces funnelform，3 -4 mm long，g labrous
minute hooked hairs outside，m inutely ciliate. inside，p ubescent with straight hairs and minute
Leaves evergreen，pi nnately 3-foliolate，pe tio- hooked hairs outside，4- 10bed above middle，th e
late，1 7-25 cm long; the petioles 9-15 cm long， tube about 1.5m ml ong，th e upper lobe bifid at
rather densely covered with patent，lo ng，st raight apex，t he lateral ones triangular，a cuminate，
hairs up to 0.5 mml ong，a nd minute hooked 1.5-2 mml ong，t he lowest one longer than the
hairs; the blade thick chartaceous，e ntire，t he laterals，1. 7-2.2 mml ong. Standard unknown;
upper surfaces seemingly glabrous but densely wings and keel-petals long clawed，th e claw about
covered with very minute hooked hairs，th e lower 3m ml ong，ke el-petals puberulent inside. Androe-
surfaces velutinuous with dense，s traight，s oft cium diadelphous，a bout 7m ml ong，gl abrous.
hairs，of ten somewhat glaucous，th e reticulate veins Pistils stipitate，3 -4ovulate，the style incurved，
・
prominent，t he principal lateral nerves 6t o 7 glabrous. Mature pods unknown; the young one
on each side of midrib，p rominent and directly flat，s talked (Fig. 2)，3 -4-jointed，with dense
・
reaching margin (Fig. 2); the terminal leaflets uncinate hairs and with reticulate-veins on walls，
ovate，7 -8 cm long and 4.5-5 cm wide，ac ute at both sutures thickened，g labrous，c onstricted
apex，ob tuse to rounded at base; the rachis 3.5-5 between the seeds，is thmus less than 1/4a s broad
cm long，ha iry like the petiole; the lateralleaflets as the pod (Fig. 2)，y oung articles elliptic. Seeds
obliquely ovate，a l ittle smaller than the terminal unknown.
one.
Fig. 2. Desmodium vidalii Ohashi，a. lateral leaflet showing venation (x 1.2)，
b. young pods (x 1.2).
December 1992 Journal of Japanese Botany Vol. 67 No. 6 323
According to the note on the label of the type Herbaria. This study is supported by the Grant-
specimen，th e plant was collected at af issure on in-Aidf or Scientific Research (04640635) from the
al ining of ar ocky grotto. Such ah abitat is，as far 恥1inistryof Education，S cience and Culture of
as 1k now，qu ite exceptional for Desmodium plants Japan.
so far known. The new species is probably very
rare in occurrence. Nod uplicates have been found References
in P，a nd complete flowers and mature pods and Ohashi H. 1973. The Asiatic species of Desmodium and
its allied genera (Leguminosae). 318 pp.，7 6 pls.
seeds could not be examined. Ginkgoana 1. Academia Scientific Book，In c.，To kyo.
一一一一一1990.Desmodium schubertiae (Leguminosae)，a
Desmodium vidαlii is characteristic in having
， new species from Cambodia and Vietnam. J. Arnold
short zigzag stems (about 10 cm high) bearing Arb. 71: 381-384.
several patent long-petioled 3foliolateleaves 一一一一， Polhill R. M. and Schubert B. G. 1981. Des-
・ modieae. In Polhill R. M. and P. H. Raven (eds.)，
(which are 17-25 cm long)，e vergreen leaves of Advances in Legume Systematics，Pa rt 1，29 2-300.
which the terminalleaflet has long rachis (3.5-5 Royal Botanic Gardens，K ew，E ngland.
cml ong)，lo osely flowered，el ongate inflorescences
要 旨
(30-45c m long) with 2o r 3f lowers at each node，
and densely hooked-hairy pods. However，se veral Flore du Cambodge du Laos et du
Vietnamのヌスピトハギ属を執筆するため，
features of the new species suggest as imilarity to
Laboratoire du Phanerogamie所蔵の未同定標
some species of the subgenus Podocarpium.
本を同定中， 1930年ラオスで採集された未知のヌ
Common characteristics between D. vidalii and
スビトハギ、属の植物を見つけた.葉だけを見ても
Podocarpium species are deeply constricted，lo ng
著しい特色があり 既知のどの種とも異なるもの
stipitate，an d hooked-hairy pods，la x-flowered long
であった.葉柄は茎よりも長く，頂小葉には長い
inflorescences，a nd an herbaceous habit with
葉軸があり(図1)，小葉柄は非常に短く，側小葉
evergreen子foliolateleaves. D. viaαlii is，th erefore， はやや無柄にみえる(図2).この標本は1枚だけ
placed in the subgenus Podocarpium，bu t detailed
で，残念なことに完全な花も成熟した豆果や種子
position of the new species within the genus may もない，不完全なものであった.重複品を探し出
be determined only after examining complete してより完全な記載を作ってから発表したいと考
flowers and mature pods with seeds. Additional え，同研究所のJ.E. Vidal博士に探索を依頼し，
material is much needed for further studies. また私自身も同研究所所蔵のインドシナからのマ
メ科の未同定標本を調べてみたが，別の標本を発
1a m thankful to Drs. J. E. Vidal and P. dy 見できなかった.1枚だけの標本に基づく判断で
Phon of Laboratoire de Phanerogamie，M useum はあってもこの植物が新種であることは間違いな
いと思われるので ここで Desmodiumvidalii
National d'Histoire Naturelle，fo r their help during
と命名し，発表しておくこととした.標本が不完
this study. 1a mm uch indebted to Dr. Bernice G.
全であるため，この新種の属内の分類学上の位置
Schubert of the Arnold Arboretum of Harvard
を厳密には決定できないが，小形の草本で，常緑
University for her advice when 1h ad investigated
の3小葉からなる葉をつけ，豆果はかぎ毛で密に
the specimen described here as new at the Harvard
被われていて節で深くくびれ基部に柄のあるこ
University Herbaria in 1988 and for her invaluable
と，さらに花序は長く，節はまばらで，各節に2-
comments on the manuscript. 1a mg rateful to Dr. 3花をつけるなどの特徴を総合してみると，
D. E. Boufford and Ms. E. W. Wood for their Podocarpium亜属の種と判定してよいと考える.
support during this study at the Harvard University