Schismatoglottis porpax S.Y.Wong, Kartini & 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 : 965

Schismatoglottis porpax S.Y.Wong, Kartini & P.C.Boyce

Material examined. MALAYSIA – Pantai Barat • Kota Kinabalu, Inanam, Kionsom Waterfall ; 05°58′26′′N, 116°12′30′′E; 270 m elev., Wong Sin Yeng & P. C. Boyce AR-4684 (holo, SAN, iso, SAR) .

Identification. Schismatoglottis porpax is most similar to S. hayi S.Y.Wong & P.C.Boyce , a species endemic to the forested Karst limestone of Niah Caves in northeastern Sarawak (Wong and Boyce 2011), notably in the leaf blade shape and pubescent petioles. It can, however, be distinguished from that species by leaf blades not producing adventitious plantlets, and by the longer, narrower pistillate flower zone, the much smaller sub-pistillar sta- minodes (the smallest so far known in the Multinervia Complex), a sparsely-cloted interstice with staminodes about half the size of those in S. hayi , and by a narrower appendix. The elongated leaf blades of S. porpax are quite different to the ovate blades of S. multinervia M.Hotta ( Boyce and Wong 2015) , a species restricted to the forested Karst formations in the Mulu National Park, while the spadix of the two species differs in several key characteristics ( Wong et al. 2019).

Distribution and ecology. Endemic to Sabah. Known only from the type locality at Kionsom waterfall when it occurs in abundance along a 500 m stretch of the trail to the first waterfall. Moist lowland forest growing on Oli- gocene deep water sandstones, mostly occurring on the lower parts of shady and rocky banks kept permanently wet by seepage, elevations between 200 and 300 m.