Studies on Schismatoglottideae (Araceae) of Borneo XXIV – Two new species of Aridarum from Kalimantan, and notes on the Aridarum Burttii Complex

Publication Type:Journal Article
Year of Publication:2012
Authors:YENG, W. O. N. G. S. I. N., Boyce, P. C., LING L. O. W. S. H. O. O. K.
Journal:Willdenowia. Mitteilungen aus dem Botanischen Garten und Museum Berlin-Dahlem. Berlin-Dahlem
Start Page:261
Date Published:12/2012
Keywords:Aridarum kazuyae, Aridarum orientale, aroids, Indonesia, rheophyte, taxonomy

Two taxonomically novel Aridarum species, A. kazuyae and A. orientale, are described from Kalimantan Timur, Indonesian Borneo. They are most similar to A. burttii from Sarawak, and together with A. minimum from Kalimantan Barat represent a morphotaxon, here called the Burttii Complex, defined by staminate flowers comprised of one stamen with an obliquely excavated expanded connective, hemispherical interstice staminodes, a spathe limb deliquescing acroscopically from its junction with the lower persistent portion and leaf blades with adaxially prominently raised primary lateral veins. Recognition of the new species proposed here takes the genus Aridarum to 12 accepted species. A key to all Aridarum species is provided, the two new species are illustrated and a comparison plate of the spadices of the four species assigned to the Burttii Complex as well as notes on the defining morphological features of this species group and some brief observations on pollination are given.

Full Text

Aridarum Ridl., a genus of 10 accepted species of obligate rheophytes endemic on Borneo, was last revised by Bogner & Hay (2000), who recognised eight species, including one novelty, and one distinct but undeterminable species represented by sterile material only. Since then, A. minimum H. Okada (2006) was described and, based on new collections, A. crassum S. Y. Wong & P. C. Boyce was established (Wong & Boyce 2007) for the indeterminable taxon highlighted by Bogner & Hay (2000). Since 2007, examination of more herbarium material coupled with extensive and continuing fieldwork has revealed further undescribed Aridarum species. Two novelties resulting from this fieldwork are here described.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith