The stems of Polystachya transvaalensis are covered in old leaf sheaths that are tubular and usually black. The pseudobulbs of this species are thin, cylindrically elongated, only about 5 mm wide, but varying in length from 8 cm to 22 cm.

Two to five leaves sheathing at the base grow on a stem. The leaves become 15 cm long and 2 cm wide. They have blunt, rounded tips (Pooley, 1998; www.orchidspecies.com).