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Gardens' Bulletin Singapore 52 (2000) 257-259. 


A New Species of Lasianthus (Rubiaceae) from 
Peninsular Malaysia 

H. ZHU 

Xishuangbanna Tropical Botanical Garden, 

The Chinese Academy of Sciences 
Kunming 650223, Yunnan, P.R. China 


Abstract 

A new species of Lasianthus Jack (Rubiaceae) from Peninsular Malaysia, named as 
Lasianthus malaiense H. Zhu, is described. 


Introduction 

Species of the genus Lasianthus Jack from Peninsular Malaysia were studied 
by Wight (1846), Hooker/. (1880), King & Gamble (1904), Ridley (1923) 
and more recently by Wong (1989). However, there are still some specimens 
undetermined and even taxa unrecognized owing to the difficult taxonomy 
of the genus. Specimens of the genus from Peninsular Malaysia in SING 
and KEP were fully checked by the author as part of a revision of the 
genus for Flora Malesiana. An undescribed species from Peninsular 
Malaysia was recognized as a new species and is described below. 

Lasianthus malaiense H. Zhu, sp. nov. 

Lasianthus ‘sp. 6’ Wong, Tree FI. Mai. Pen. 4 (1989) 372 (in clavi). 

A Lasianthus robinsonii Ridl. petiolis 5 mm longis, foliis subtus dense 
brunneo-villosis, nervulis parallelis; pedunculis robustis 2—3 cm longis; 
lobis calycis 5, lanceolatis, 2.5 mm longis differt. Proxima L. pendulo Ridl. 
sed petiolis conspicuis, 5 mm longis, foliis ovato-oblongis apice acutis basi 
rotundatis, nervis supra planis, nervulis parallelis; bracteis 2, 7—8 mm longis; 
lobis calycis lanceolatis 2.5 mm longis, corollis brunneo-villosis differt. 
TYPUS: Peninsular Malaysia — PAHANG, Cameron Highlands, alt. 5000 
ft, 27 Nov 1925, Henderson 18008 (holotype, SING) 

Shrub c. 2 m tall with densely spreading brown-villose hairs on the branches 
and branchlets, stipules, petioles, on the underside of midrib and veins, 
inflorescence, bracts, calyx, corolla and drupe. Branches and branchlets 


258 


Gard. Bull. Singapore 52 (2000) 


robust. Stipules triangular, c. 3 mm long. Petiole c. 5 mm long, lamina 
subcoriaceous, glabrous above, ovate-oblong to elliptic, 6—15 cm long, 
2.5—5.5 cm broad, base rounded or obtuse, margin reflexed, apex acute to 
cuspidate; midrib, secondary and tertiary veins plane above and 
conspicuously prominent beneath; secondary veins 7—10 pairs; tertiary 
veins parallel. Cymes peduncled; peduncles robust 2—3 cm long, bracts 2, 
linear, 7—8 mm long; bracteoles inconspicuous. Flowers subsessile; calyx 
3—4 mm long with 5 lanceolate lobes, lobes c. 2.5 mm long; corolla brown- 
villose. Drupes subglobose, c. 5 mm diam., crowned by persistent calyx 
lobes; pyrenes 5. 

Distribution : Endemic to Peninsular Malaysia (Pahang and Terengganu). 

Habitat : Montane forests between 1150 and 1600 m altitude. 

Notes : Prior to the account by Wong (1989), specimens of Lasianthus 
malaiense had been identified as L. robinsonii Ridl.. However, L. malaiense 
differs from L. robinsonii. which has oblong leaves with the shorter petioles, 
less dense pubescence on the under surface of the midrib, secondary and 
tertiary veins, subreticulate tertiary veins; slender and longer peduncles; 
four linear calyx lobes, 6 mm long and drupes with four pyrenes: and from 

L. pendulus Ridl., which has ovate-lanceolate leaves with the shorter petioles 
(to 2 mm long), the lamina apex is acuminate to caudate, the base slightly 
cordate; the veins are conspicuously depressed above; the tertiary veins 
are reticulate; the bracts numerous, linear, to 1.2 cm long; the calyx lobes 
are linear and c. 6 mm long. 

There is some confusion in the determinative labels on sheets in SING and 
KEP. Specimens Henderson 18008 (SING) and Chew 764 (SING) are 
determined as Lasianthus ‘sp. 7’ by Wong (but cited as ‘sp. 6' in Wong's 
key, 1989). The specimen Jaamat 27273 has a label determined as Lasianthus 
‘sp. T in SING but as Lasianthus ‘sp. 6’ in KEP. Using Wong's key. 
specimens of L. malaiense key out as his 'sp. 6’. 

Specimens examined : Peninsular Malaysia - PAHANG: Cameron Highlands 

M. R. Henderson 18008 (SING), W.L. Chew 764 (SING), K.M. Wong FRI 
35229 (SING), Henderson s.n. (SING); Ulu Telom, Jaamat 27273 (KEP. 
SING); Gunong Tahan, H.N. Ridley 16069 (SING); TRENGGANU: 
Gunung Padang L.Moysey et Kiah SFN 33940 (SING). 


Lasianthus from Peninsular Malaysia 


259 


Acknowledgements 

1 thank the Director of Singapore Botanic Gardens (SING) for permission 
to use Herbarium and Library and the Curator of the Herbarium of Forest 
Research Institute of Malaysia for referencing specimens. I thank Dr Ruth 
Kiew and her staff for their help during my visit to SING. I also acknowledge 
Dr Ruth Kiew for editorial changes and anonymous reviewers for comments 
on this article. Thanks also to the Chinese Academy of Sciences for the 
Fund for Top One Hundred Young Scientists and KZ951-A1-104 Project. 


References 

Hooker, J. D. 1880. Lasianthus. Flora of British India. 3: 178—192. 

King, G. and J.S. Gamble. 1904. Lasianthus. Materials for Flora Malay 
Peninsula. 15: 106—133. 

Ridley, H. N. 1923. Lasianthus. Flora of the Malay Peninsula 2 : 149—169. 

Wight, R. 1846. Lasianthus. Calcutta Journal of Natural Historv. 6: 494— 
518. 

Wong K. M. 1998. Lasianthus. Tree Flora of Malaya. 4: 367—373.