Psychotria euosma I.M. Turner

Turner, I. M. & Kumar, V. S., 2018, Flora of Singapore precursors, 4. A summary of scandent Psychotria (Rubiaceae) in Singapore and Peninsular Malaysia, Phytotaxa 361 (2), pp. 183-197 : 188

4. Psychotria euosma I.M. Turner , stat. et nom. nov.

≡ Psychotria sarmentosa var. montana Ridley (1923: 131)

Type (lectotype, designated here): PENINSULAR MALAYSIA. Pahang: Gunong Tahan, Jul 1911, H. N. Ridley 16068 ( K barcode K 000777156).

Specimens examined: — PENINSULAR MALAYSIA. Kedah: Kedah Peak , 8 May 1938, C. F. Symington KEP 46904 ( K) ; Kedah Peak , 2 Dec 1915, H. C. Robinson & C. Boden Kloss 6032 ( K) ; Trengganu: Gunong Padang , 4000 ft, 19 Jun 1937, L. Moysey & Kiah SFN 31887 ( K) ; Malacca; Mt Ophir , Aug 1867 -1868, A. C. Maingay 2747 [kdn 922] ( K) ; Pudda, W. Griffith s.n. [kdn 3043] ( K). THAILAND. Nakhon Si Thammarat: Khao Luang , 750–950 m, 22 May 1968, C. F. van Beusekom & C. Phengklai 929 ( K) ; Phangnga: Khao Paw Ta Luang Keo, 1000–1300 m, 29 Apr 1974, K. Larsen & S. S. Larsen 33509 ( K) .

Notes: —Ridley associated this taxon with Psychotria sarmentosa Blume (1826: 964) , but with its fleshy leaves it seems closer to P. serpens and little akin to P. sarmentosa . The collections from the mountains of Peninsular Malaysia and Peninsular Thailand included here form a coherent entity with distinctive coriaceous, acuminate leaves that dry olive green or brown with scarcely discernible venation. They come close to P. tahanensis Ruhsam in Ruhsam et al. (2008: 116) ( P. brachybotrys Ridley (1909: 38)) which has similar leaf form, though generally drying chestnut or greybrown. However, P. tahanensis has smaller, darker stipules, generally smaller inflorescences with glabrescent axes and flowers compared to the dense but short pubescence of P. sarmentosa var. montana . The pyrenes have sharp-edged ridges in var. montana but they are more rounded in P. tahanensis . It seems best therefore to consider P. sarmentosa var. montana as a separate species. As the eipthet montana is already pre-empted at specific rank in Psychotria , a new epithet is given here. That chosen, euosma, is Greek for fragrant, and reflects a field note on a collection from Thailand (Beusekom & Phengklai 929) which states that the flowers are very sweet-scented.