Rhaphidophora sylvestris (Blume) Engl.

Wong, Sin Yeng & Joling, Jyloerica, 2021, Checklist of aroids (Alismatales, Araceae) from Sabah (Malaysian Borneo), Check List 17 (3), pp. 931-974 : 960-961

Rhaphidophora sylvestris (Blume) Engl.

Material examined. MALAYSIA – Pantai Barat • Ranau Tenompok ; 1524 m elev.; 14 April 1932; Clemens & Clemens 29227 (L, P) • Ranau, Bukit Hampuan ; 06°00′53′′N, 116°41′50′′E; 17 November 1987; Amin & Jarius SAN 121155 ( SAN) • Ranau, Mount Kinabalu-Mesilau Valley ; [05°59′11″N, 116°36′17″E]; 1524 m (5000 ft.) elev.; 29 September 1972; Cockburn SAN 70108 ( SAN) • Ranau, Mount Kinabalu, Dallas ; [06°5′30″N, 116°32′45″E]; 2 November 1931; Clemens & Clemens 26921 (L) • same locality, 914.4 m (3000 ft.) elev.; 10 November 1931, Clemens & Clemens 27030 (L) • same locality; 1828.8-4114.8 m (6000-13500 ft.) elev.; 8 April 1932, C.X.Furtado 28487 (L) .

Identification. Rhaphidophora sylvestris is more variable in Borneo than in other parts of its range (e.g., Peninsular Malaysia, Java) but the paucity of collections coupled with more or less continuous variation makes it impossible to be confident that more than one species is involved. Of particular notes is the occurrence of plants with coriaceous leaf blades that have variously been described as Rhaphidophora gratissima Becc. (syn. R. sylvestris var. obtusata Engl. ) and R. nigrescens Ridl. Such plants approach R. conocephala Alderw. in appearance (and also resemble non-Bornean R. crassifolia Hook. f.), although the flat-topped styles readily distinguish them

from R. conocephala , while the juvenile shoots without conspicuously twisted stems separate them from R. crassifolia . Leaf blade thickness is not a consistent character, even between duplicates of the same collection (Boyce 2001).

Distribution and ecology. Northwestern Sabah. Primary to disturbed secondary lowland to lower montane forest on a variety of substrates including sandy loam and limestone. 120–1800 m elev.