Panisea uniflora Lindl. (Orchidaceae) was first reported from Perlis in Peninsular Malaysia in 2005 (Yong et al., 2005). Previously, this genus is recorded from Nepal to China and Indo-China as far south as Thailand.

A single specimen was found in a damp shady valley at the foothill of Bukit Wang Pisang, a limestone hill in Perlis. It is easily distinguished from other orchids by the long-necked bottle-shaped pseudobulbs, a character not found in other species in Peninsular Malaysia.

It is an epiphytic herb with a very short rhizome. The pseudobulbs are close together, arranged alternately in two rows, is bottle-shaped with the terminal portion elongated, 1.4–3.2 × 0.6–1.25 cm, widest at the middle, base constricted, the base covered with overlapping sheaths. It has two leaves at the top of the pseudobulb, very shortly petiolate or nearly sessile, twisted at the base, linear to narrowly lanceolate, 7.1–11.8 × 0.9–1.1 cm, l/w 7.9–10.7 cm, tip acute. Inflorescence of a solitary flower, arise from the base of the pseudobulb. Lip of the flower trilobed, base constricted, 18 × 7 mm, l/w 2.6; keels 2, inconspicuous, from the base reaching to the middle of the epichile; lateral lobes falcate, apex rounded; epichile linear in outline, 9 ×5 mm, margin undulate, apex rounded. Column 9 mm long, with broadly rounded wings.

Panisea uniflora is a predominantly Indo-Malayan species, recorded from India, Myanmar, Thailand, Laos, Cambodia, and Vietnam. It is therefore not surprising to encounter this species in Perlis, which floristically belongs to the Indo-Malayan division of the Malaysian flora.