Homalomena galbana Baharuddin & P.C.Boyce

Wong, Sin Yeng & Joling, Jyloerica, 2021, Checklist of aroids (Alismatales, Araceae) from Sabah (Malaysian Borneo), Check List 17 (3), pp. 931-974 : 950

Homalomena galbana Baharuddin & P.C.Boyce Figure 4B

Material examined. MALAYSIA – Sandakan • Maliau Basin Conservation Area, environs of Camp Ginseng, 2005, Baharuddin 11076 (holo, Universiti Sains Malaysia).

Identification. Homalomena galbana is immediately distinguishable from all other described Bornean species

by the combination of its mesophytic habit and comparatively large spathe lacking a constriction between the lower spathe and limb. The only described species in Borneo with a similar spathe is H. expedita , but this is a colonial helophyte, has markedly different spa- dix morphology, and has yet to be recorded from Sabah. Among mesophytic species some larger expressions of H. griffithii (Schott) Hook. f. [Chamaecladon Supergroup] are vaguely similar in appearance to H. galbana but differ by the smaller spathes (less than 2 cm long), the interpistillar staminodes much shorter than the associated pistils, and smaller infructescences. The spathe becoming yellow at anthesis is highly distinctive and represents a novel morphology for Homalomena ; furthermore, yellow is a rare spathe colour among terrestrial mesophytic aroids in general ( Baharuddin and Boyce 2010).

Distribution and ecology. Endemic to Sabah. Known only from the type collection. Perhumid evergreen upper hill forest on mudstone, along small streams, ca. 700 m elev.