Studies on Homalomeneae (Araceae) of Sumatera I: Homalomena hypsiantha, a distinctive new species of the Chamaecladon Supergroup

As stated in previous papers (e.g., Kurniawan et al., 2011; Wong & Boyce, 2011) considerable taxonomic and nomenclatural problems beset Chamaecladon Homalomena. Nonetheless, there remains a pressing need to establish a framework of taxa for which no taxonomic doubt exists. It seems certain that Alderwerelt felt much the same way when faced with considerable living collections for which there were no obviously assignable names. To this end the publication of formal names for taxa that are without question distinct from all others is a vital step. The species described here is one such.
Recognition of Homalomena hypsiantha takes the number of Homalomena described for Sumatera to 27; all are endemic. Twenty-one belong to the Chamaecladon Supergroup (sensu Boyce & Wong, 2008), with 11 of these described by Alderwerelt (1922). As previously noted (Boyce et al., 2009: 8–9) there is a tendency to dismiss Alderwerelt’s aroid work. It must be admitted that a significant problem with interpretation of Alderwerelt’s aroid taxa is that much of the preserved material is depauperate. It seems highly probable that he (rightly, in our opinion) regarded the cultivated living plants as the vital data resource and presumably was unwilling to sacrifice much of this material when preparing herbarium vouchers. Alderwerelts’s species’ descrip-