Sunday, June 26, 2016

[Botany • 2016] Epirixanthes confusa • A New Species of Epirixanthes (Polygalaceaea) from Imbak Canyon, Sabah, Borneo

Epirixanthes confusa 
Tsukaya, M. Suleiman & H. Okada
DOI:  10.11646/phytotaxa.266.2.9 


The mycoheterotrophic genus Epirixanthes Blume is a small genus of Polygalaceae. Here, we describe a new species of EpirixanthesEpirixanthes confusa Tsukaya, M. Suleiman & H. Okada, discovered in the mostly unexplored Imbak Canyon, Sabah, Borneo. Along with photographs and illustrations of this new species, a revised key to the genus is presented.

Keywords: Borneo, Epirixanthes, Imbak Canyon, Malaysia, mycoheterotrophic plant, Polygalaceae, Sabah, Eudicots

Taxonomic Treatment

Epirixanthes confusa Tsukaya, M. Suleiman & H. Okada, sp. nov. (Figs. 1, 2)

Epirixanthes confusa differs from the other members of Epirixanthes in having the following features: persistent bracts even after fruit maturation, no bracteole, and pointed inflorescence apices.

Type:— Malaysia. Sabah: Imbak Canyon Conservation Area, along the Ridge Trail, alt. 622 m, 9 August 2015, Tsukaya, H. Okada, H., Hayashi, T. & Suleiman, M., No. TOH-07 (Holo- BORH, iso- TI, KYO).

Distribution:— Found in the understories of dipterocarp forest, in particular along ridges. At present, E. confusa is known to occur only in Imbak Canyon, Sabah, Borneo. However, our preliminary surveys on herbarium specimens deposited in BO suggested that some specimens collected from Java, Indonesia, annotated as “E. elongata”, are actually E. confusa (for example, BO-1791084, BO-1794915, BO-1794902, BO-1478688, BO-1478690, BO-1794913 and BO-1794910). Because E. confusa is easily mis-identified as E. elongata, detailed re-examinations of herbarium specimens are required to reveal its whole distribution

 Etymology:— The species name E. confusa denotes the confusion between this species and E. elongata

Hirokazu Tsukaya. Monica Suleiman and Hiroshi Okada. 2016. A New Species of Epirixanthes (Polygalaceaea) from Imbak Canyon, Sabah, Borneo. Phytotaxa. 266(2); DOI:  10.11646/phytotaxa.266.2.9