Nervilia ballii G.Will., Pl. Syst. Evol. 134: 66 (1980).

Erect terrestrial herb 11–30 cm tall, glabrous except for lip and subterranean parts. Tuber 15–17 × 15 × 10–15 mm in diameter, subspherical or ovoid, (2)3–5-noded.Leaf solitary, appearing after flowering, erect, 5–6 × 3–4 cm, ovate, acute, glabrous, heavily pleated, dark olive-green above with silvery lines along the veins, dark purple beneath; petiole c. 6 cm long, sulcate with 1–2 sheathing cataphylls when young. Scape erect, 1(2)-flowered, with 3–4 sheathing cataphylls, the uppermost sometimes bract-like and up to 4 cm long. Flower reddish tinged on the outside; bracts 1–2, 14–23 × 0.6–1.6 mm, filamentous to lanceolate. Sepals and petals subequal, lanceolate, acute, greenish with red veins and a general reddish tinge to the outside; lateral sepals slightly oblique, 19.5–25 × 3–4.5 mm; petals slightly shorter than sepals.Lip cream or pale yellow with a prominent red or purple venation, 18–25 × 14–18 mm, ovate to oblong-ovate, obscurely 3-lobed, bearing 2 parallel fleshy pubescent ridges from base of lip to base of mid-lobe; side lobes rounded or oblong, obtuse, erect, enclosing the column; mid-lobe ovate, reflexed. Column curved, 9–13.5 mm long, clavate, glabrous; anther front rim with two protruding teeth; anther purple; pollinia yellow, c. 2.5 mm long; ovary 4.5–5.5 mm long.

Woodland, grassland, grassland-scrub, Syzygium thicket and pine or Gmelina plantations 600–1500 m.

S. Tanzania to S. Trop. Africa

Click on each image to see a larger version.

Botanical Drawing / Herbarium
Photograph copyright Swiss Orchid Foundation at the Herbarium Jany Renz Image used with kind permission.