One of many species that is widely found in Malaysia and also neighboring countries, such as Sumatra, Java and Borneo in primary forest and humid places, between 600 - 2000m above sea level.
Briefly the plant pseudobulbs is placed 3cm or more apart on the creeping rhizome, 3-4 x 2.5cm, smooth an round when young, slightly flattened. Whereas the leaves are broadly lanceolate, about 20-25 x 6-12cm.
The flower inflorescences arised from it rhizome, penducle and pedicel together 20cm or more long, each bearing single flower, with 6 - 8cm broad, yellow, striped and flushed red
This species varies very much throughout its range, in particular in coloring and the petal length.
Picture courtesy of khairimd from http://oapm.proboards52.com/