Studies on Hanguana (Commelinales: Hanguanaceae) for Sunda IV: Hanguana major clarified, a new species from Sarawak, Malaysian Borneo, and description of male reproductive organs in H. bakoensis

Hanguana major Airy Shaw, a highly distinctive but hitherto taxonomically confused species is re-delimited and shown to be restricted to a highland area centred on Gunung Kinabalu, Sabah, with a single collection from the highlands of Limbang, Sarawak. Airy Shaw’s original Latin description is amended to omit spurious morphological data, and is presented in English. One element of the plate accompanying the original publication, determined by Airy Shaw as Hanguana malayana (Jack) Merr., is described as a novel species: H. loi Mohd Fahmi, Sofiman Othman & P. C. Boyce, endemic to SW Sarawak. A key to the described Bornean Hanguana species is provided; H. major and H. loi are illustrated. Lastly, the hitherto unknown male inflorescences and flowers of H. bakoensis Siti Nurfazilah, Sofiman Othman & P. C. Boyce are described.