Studies on Schismatoglottideae (Araceae) of Borneo XV: A Second Species of Bakoa from Indonesian Borneo

Abstract

molecular analyses Boyce & Wong (2008) and Wong et al. (2010) convincingly demonstrated Piptospatha N. E. Br. sensu Bogner & Hay (2000) to be polyphyletic. One result of redefining Piptospatha as monophyletic was the recognition of a morphologically highly distinctive new genus, Bakoa P. C. Boyce & S. Y. Wong, with one species, B. lucens (Bogner) P. C. Boyce & S. Y. Wong restricted to a single sandstone waterfall in Bako National Park, Kuching, Sarawak, and with a solitary specimen (A. Elsener H164) from Kalimantan Barat. Recent herbarium-based work in BO, L & K provided access to herbarium material not available to the author during the work leading to Boyce & Wong (2008), including the type Hottarum brevipedunculatum H. Okada & Y. Mori. On examination, this proved to represent a second species of Bakoa, differing from B. lucens by the staminate flower zone free and completely fertile [vs. basally adnate to the spathe on the dorsal side, sometimes with only the ventral-most stamens (those exposed by gaping spathe limb) fertile, or more extensively fertile, but always sterile on the dorsal side]; and the stigma reaching to almost the edge of the gynoecium. Re-examination of Elsener H164 (not critically examined previously) confirmed that this also belongs in B. brevipedunculata. Therefore, Bakoa is redefined to include the second species, B. brevipedunculata.