Studies on the Araceae of Sulawesi I: New taxa of Schismatoglottis and Homalomena, and a preliminary checklist and keys for Sulawesi

While recent years has seen a marked increase in knowledge of the woody flora of Sulawesi (e.g., Keßler et al. 2002), the herbaceous and mesophytic flora remains one of the least well-documented for any of the larger landmasses in SE Asia. Nonetheless, recent progress with Zingiberaceae (see www.dalbergpoulsen.com) and orchids (e.g., O’Byrne 1999, O’Byrne & Vermeulen 2000, 2004, 2005, 2006, 2008a, 2008b, 2009, Thomas & Schuiteman, 2002, Vermeulen & O’Byrne 2003a, 2003b, 2008), has begun to reveal an extraordinarily rich herbaceous and mesophytic flora, wherein appear to be contained a tantalizingly large percentage of endemic species. Aside from a preliminary study of the aroids part of Kolaka Regency, South-East Sulawesi (Bramantyo & Santika 2008), to date no extensive aroid-focussed fieldwork has been undertaken, although through the activities of general collectors several novel aroids, some of them spectacular, have been described in recent years, e.g., Alocasia balgooyi A. Hay (Hay 1998), A. megawatiae Yuzammi & A. Hay (Yuzammi & Hay 2003), A. suhirmanniana Yuzammi & Hay (Yuzammi & Hay 1998), Rhaphidophora sabit P. C. Boyce (Boyce 2000), and Schismatoglottis eymae A. Hay (Hay & Yuzammi 2000)
During a recent visit to Bali Botanic Gardens the third author had the opportunity to examine a remarkable collection of living aroids from Sulawesi amassed since 2000 by staff of the gardens. A considerable percentage of these collections without doubt represent taxonomic novelties. Although the majority were sterile at the time of the visit, two collections were flowering and this enabled formal descriptions to be compiled and types prepared. These two species are described below.
Including the two novelties proposed here the aroid flora of Sulawesi now comprises 40 species in 16 genera (none endemic) with one (Colocasia) non indigenous. Fifteen (35%) of the 40 species are endemic to Sulawesi, two species [Alocasia macrorrhizos (L.) G.Don and Amorphophallus paeoniifolius (Dennst.) Nicolson] occur as adventives and one (Colocasia esculenta (L.) Schott) is frequently encountered semi-naturalized as an escape from cultivation as a carbohydrate crop. These data are compiled from collections at BO, K, L, and living plants at Bali and at the Kebun Raya, Bogor. Taxonomy is from the last author’s on-going ‘Araceae of Sunda & Wallacea’ checklist (Boyce & Croat, unplub. data), Nomenclature is as per IPNI (www.ipno.org) and in part from ‘Kew World Checklist of Selected Plant Familes’—http://www.kew.org/wcsp/. See Appendix 1.