Polystachya greatrexii Summerh.

A dwarf epiphytic or lithophytic plant to 4 cm. high.. Pseudobulbs contiguous, ovoid, slightly compressed, up to 12 mm. long, 8 mm. in diameter, covered below with a few sheaths, 2-leaved above.. Leaves divergent, linear, obtuse or shortly bilobed at the apex, to 3.5 cm. long, 3 mm. broad.. Inflorescence unbranched, arising from leafless pseudobulbs, 3–3.5 cm. high, above the middle densely up to 15-flowered; peduncle covered with a few scarious sheaths; rhachis pubescent; bracts lanceolate, acuminate, 1.5 mm. long.. Flowers non-resupinate, erect-spreading, white or pale rose, lip white with a central yellow stripe, densely pubescent outside; pedicellate ovary 3 mm. long, densely pubescent.. Dorsal sepal erect, oblong-lanceolate, acute, 4–5 mm. long, 2 mm. broad; lateral sepals obliquely lanceolate-ovate, subacute, 4.5 mm. long, 2.5 mm. broad; mentum obtuse, obscure, 1.5–2 mm. high.. Petals oblanceolate or oblong-oblanceolate, subacute, 4–5 mm. long, 2 mm. broad.. Lip strongly recurved, elliptic to oblong, 4 mm. long, 2.5 mm. wide, subacute to apiculate, base rotund; disc densely farinaceous-papillose.. Column short, fleshy, 1 mm. high.. Fig. 78, p. 376.