Wednesday, December 11, 2024

[Botany • 2024] Psychotria oxyalabastron (Rubiaceae) • A New Species and A New Record of Psychotria from Thailand

 

Psychotria oxyalabastron T.Srisuk & Chamch.,

in Srisuk, Chamchumroon, Chantaranothai et Pornpongrungrueng, 2024.  
 พาโหมดง  || DOI: doi.org/10.20531/tfb.2024.52.2.16 

Abstract
A new species, Psychotria oxyalabastron, is described, and P. laui is newly recorded from Thailand. The description, distribution area, ecological information and taxonomic note are provided.

Keywords: Gentianales, Psychotria laui, Psychotria oxyalabastron, Psychotrieae, Taxonomy

Psychotria oxyalabastron T.Srisuk & Chamch.:
A. flowering branch; B. stipules, outer surface; C. stipules, inner surface with hairs and colleters; D. floral bud; E. flower, dissection; F. pyrene, side view; G. pyrene, cross section; H. seed, dorsal view; J. seed, ventral view.
Materials A.–E. from Hansen & Smitinand 12045 (E); F.–J. from van Beusekom & Phengklai 925 (K). Drawn by T. Srisuk.


Psychotria oxyalabastron T.Srisuk & Chamch., sp. nov.

Psychotria oxyalabastron is similar to P. cambodiana Pierre ex Pit. in having tomentose, puberulous or pilose indumentum on branches and the lower leaf surface (at least on the venation), bifid or bilobed stipules, elliptic or oblanceolate laminas, loose corymbose-like thyrsiform inflorescences, and glabrous floral buds. However, it differs from P. cambodiana in the glabrous upper leaf surface (vs pilose), glabrous on intercostal areas on the lower leaf surface (vs pilose), acute floral bud apex with corolla protrusion (vs rounded floral bud apex without corolla protrusion), shorter corolla tube 1.3–1.4 mm long (vs 2–2.3 mm long), and the glabrous to sparsely puberulent ovary (vs tomentose or pilose).



Etymology.— The specific epithet ‘oxyalabastron’ refers to the acute shape of the floral bud, and is modified from the Greek “oxy-” for acute, combined with “alabastrum” for floral bud (alabastron = adjective form).
Vernacular.— Pha hom dong (พาโหมดง) (proposed here).



Teerawat Srisuk, Voradol Chamchumroon, Pranom Chantaranothai and Pimwadee Pornpongrungrueng. 2024. A New Species and A New Record of Psychotria (Rubiaceae) from Thailand. Thai Forest Bulletin (Botany). 52(2), 110–117. DOI: doi.org/10.20531/tfb.2024.52.2.16