Thelymitra malvina

Detailed description

Glabrous, terrestrial orchid. Tubers ovoid 10–30 × 5–12 mm, fleshy, pinkish-grey. Leaf linear to linear-lanceolate, 100–350 × 5–20 mm, light to dark green with a purple base, erect, canaliculate, fleshy, abaxial surface ribbed, sheathing at base, apex acute. Inflorescence 0.25–0.75–(0.9) m tall, 1.5–5.0 mm diameter, stout, fleshy, straight, green to purple-green. Sterile bracts (2)–3, linear to linear-lanceolate, 20–100 × 4–11 mm, closely sheathing, acute to acuminate, green or purple-green, upper bract usually free with base usually only half encircling the scape. Fertile bracts 8–30 × 3–6 mm, green or purple-green, ovate-acuminate to obovate-acuminate, sheathing the pedicels. Pedicels 5–15 mm long, slender. Ovary cylindrical to narrow-obovoid, 5–12 × 2–4 mm. Flowers 3–25, 18–32 mm diameter, slate blue to mauve inside, sepals greenish outside, opening readily in warm weather. Perianth segments 8–16 × 3–7 mm, concave, acute, shortly apiculate; dorsal sepal elliptic to lanceolate; lateral sepals elliptic to lanceolate, asymmetric; petals ovate to lanceolate; labellum elliptic to linear-lanceolate, often narrower than other segments. Column erect, 6–7.5 × 2.5–3.7 mm, mauve; post-anther lobe cucullate, 2–4 × 1.5–2.5 mm, tubular, inflated, compressed dorsally, curved gently, dark reddish brown, apex shallowly bilobed, lobes toothed, orifice small, yellow; post-anther lobe extension 0.6–0.2 mm; auxiliary lobes absent; lateral lobes converging 1–1.5 mm long, digitiform, obliquely erect, each with a more or less terminal, dense, broom of mauve or pink cilia 1–1.5 mm long. Anther inserted near middle of column, ovoid, 2.5–3.5 × 1.2–2.2 mm, the connective prolonged into a 0.5–1.0 mm long beak. Stigma at base of column, 1.8–2.6 × 1.5–2.5 mm, ovate-quadrate. Capsules 12–20 × 4–6 mm, obovoid, erect, ribbed.