Dendrobium crocatum Hook.f. (Orchidaceae): A newly recorded species in Indonesia

A newly recorded species,Dendrobium crocatum Hook.f., in Indonesia is described and illustrated. This species was described in 1890 and it was restricted to Peninsular Malaysia and southern part of Thailand. Since described for the first time, there is never any records about this orchid discovery outside from these areas. But on March 2010, several living specimens of this species was recently found in Indonesia, precisely in the lowland forest of Siberut island – western part of Sumatra Island. But so far, there was no evidence for the existence of this species in Sumatra Island, although Sumatra is a large geographical spans which became separator between Peninsular Malaysia to the Siberut Island. Although Siberut’s specimen morphology is not too far with Malaysian specimen, but there is slightly difference on the floral color. The taxonomic treatment, morphological descriptions, photographs and notes of the species are given here. A key to distinguish it from the other closely related Sumatran Calcarifera’s Dendrobium is also provided.