The Lesser Sunda Islands (LSI) comprise many small islands of two countries, Indonesia (the majority of the islands), and Timor Leste (comprising the eastern portion and a discrete north western enclave of Timor Island). In Indonesia, administratively, the LSI belong to three provinces: Bali, Nusa Tenggara Barat (comprising Lombok and Sumbawa Islands), and Nusa Tenggara Timur (comprising Sumba and Flores
Islands, and most of the western half of Timor Island). The LSI are among the least well investigated parts of Malesia for many families, including the Araceae, although in the past five years fieldwork in the LSI focusing on Araceae has been undertaken by the first and second authors. One aim of this fieldwork has been to establish a living research collection in the Bali Botanical Garden, an essential prerequisite for working on the aroid flora. From this so far three novelties from Sumbawa and Lombok have been identified (one species of Alocasia and two of Homalomena), all as yet undescribed, together with at least 10 new species records for Bali.
Alocasia comprises about 100 species of mainly understory herbs from humid evergreen tropical and subtropical forest in Asia and Australia (Boyce 2007, 2008; Hay 1998, 1999, 2000; Hay & Wise 1991; Kurniawan & Boyce 2011; Medecilo et al. 2007; Nauheimer et al. 2012). The latest monograph for Alocasia of West Malesia and Sulawesi is Hay (1998), since when several additional species have been described from Borneo (Hay 2000; Boyce 2007, 2008; Kurniawan & Boyce 2011). A recent phylogeny of Alocasia by Nauheimer et al. (2012) suggested several dispersal events leading to speciation in Malesia, and revealed that Alocasia and Leucocasia (formerly Colocasia) gigantea (Blume) Schott formed a lineage separate from the rest of the Colocasieae sensu Mayo et al. (1997).
Hay (1998) records only one Alocasia species for the Lesser Sunda Islands, the widespread cultivated/feral and certainly non-indigenous A. macrorrhizos (L.) G.Don. Over the course of fieldwork on Bali and Lombok, plants of what are without doubt A. alba (Fig. 1) have been encountered in habitats well-away from possible human introduction, such that we are now confident that Alocasia alba is naturally occurring on these islands, representing a new distributional record for a species until now considered primarily a Javan species (Hay & Yuzammi 2000).