|Year of Publication:
|YENG, W. O. N. G. S. I. N., Boyce P. C.
|Willdenowia. Mitteilungen aus dem Botanischen Garten und Museum Berlin-Dahlem. Berlin-Dahlem
|aroids, identification key, Piptospatha burbidgei, Piptospatha elongata, taxonomy
Piptospatha pileata, a new species of the Araceae tribe Schismatoglottideae from Kalimantan Timur province, Indonesian Borneo, is described, comparatively illustrated and delimited from P. burbidgei and P. elongata, and included in a revised key to the species of the genus.
Working in herbaria with significant holdings of Schismatoglottideae (notably BO, L and SAR, herbarium abbreviations following Thiers 2008+) has revealed that specimens of obligate rheophytic species of this tribe are comparatively abundant, but also that significant problems exist with their taxonomic interpretation. To begin with, many display very close similarity in overall appearance owing to vegetative adaptations to habitat. Furthermore, specimens are frequently sterile, while fertile material is often collected post-anthesis or suffers postpreservation damage to critical floral features. In all cases this renders the specimen indeterminable. Even fertile, undamaged specimens suffer from the common neglect by the collector (usually a non-specialist) to prepare fresh inflorescences for examination by opening/removing the spathe to reveal the spadix before pressing; removing the spathe from a dried specimen without damaging the underlying, often adhering, spadix is almost impossible. It is also very seldom that alcohol-preserved inflorescences are prepared, and almost never are these distributed with duplicates. Lastly, even more seldom is a set of useful photographs available to ‘enrich’ inadequate material. These comments apply as well to the most recent collections as they do to the historical.
One approach to reduce the taxonomic burden of unnamed (unnameable) material of likely novel species is to visit localities of the collections and attempt a match between plants on the ground and pre-existing collections. One such novel species is the subject of this paper. Piptospatha N. E. Br. is a genus of 11 species, the majority confined to NW and C Borneo (Bogner & Hay 2000; Wong & al. 2009, 2011). All described species have a narrow to moderately restricted distribution, and are often confined to a particular geology. To date only two species have been described from NE Borneo: P. burbidgei (N. E. Br.) M. Hotta, and the enigmatic P. insignis N. E. Br. (Boyce & Wong 2011). During examination of the herbarium material at BO and L we encountered a collection (J. A. McDonald & Ismail 3615) originat-ing from the Indonesian Kalimantan Timur province and matching neither of the known NE Bornean species, but insufficient to enable description. As customary, a digital image of the duplicates was added to our rather considerable ‘sp. nov. caveat actor’ folder, and no further action was possible until the arrival of images taken in the field in Kalimantan Timur. These showed a clearly distinct Piptospatha and prompted re-examination of J. A. McDonald & Ismail 3615, convincing us that the images and the collection are the same, scientifically novel, species.
It is here described.