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

Wong, Sin Yeng & Joling, Jyloerica, 2021, Checklist of aroids (Alismatales, Araceae) from Sabah (Malaysian Borneo), Check List 17 (3), pp. 931-974 : 963

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

Figure 6D

Material examined. MALAYSIA – Tawau • Lahad Datu, Danum Valley Conservation Area, Tembaling Falls trail; 05°01ʹ01″N, 117°44ʹ40″E; 281 m elev., 6 July 2018, Wong Sin Yeng, P.C. Boyce & Kartini Saibeh BORH 2703 (holo, SAN) .

Identification. Schismatoglottis clivemarshii is most similar to S. venusta A.Hay by hapaxanthic shoots, rather coriaceous, slightly succulent leaf blades that are often variegated, a pistillate flower zone adnate to the spathe for about half its length, a staminate flower zone entirely exserted from the lower spathe chamber, thecae with the rim of the pore broken by a slit on the outer side, and by an unbroken row of staminodes along adnation of spathe and spadix. Schismatoglottis clivemarshii differs from S. venusta by glabrous petioles D-shaped in cross-section and narrowly crisped-alate on the angles (vs. minutely puberulent petioles terete in cross-section and lacking wings), by the presence of a well-defined naked sterile interstice (vs. sterile interstice ill-defined, with the apex

of the pistillate flower zone attenuate and partly naked, or sometimes with a few abortive ovaries and reduced interpistillar staminodes contiguous with the base of the staminate flower zone), by a shorter, stouter pistillate flower zone, with more laxly arranged, better-defined and larger staminate flowers, and by an appendix base wider than the top of the staminate flower zone (vs. isodiametric). The two species may also be separated ecologically, with S. clivemarshii restricted to Miocene Melange outcroppings whereas S. venusta occurs lithophytically or chasmophytically on Karst limestone ( Boyce et al. 2019).

Distribution and ecology. Endemic to Sabah. Known only from two separate localities, approximately 10 km distant, the Danum Valley Conservation Area. Restricted to Miocene Melange outcroppings through Cretaceous deepwater sediments in lightly shaded lowland perhumid forest between elevation 215 m and 310 m elev.