Thelymitra sparsa is a tuberous, perennial herb with a single erect, fleshy, channelled, linear to lance-shaped leaf 60–250 mm (2–10 in) long and 2–5 mm (0.08–0.2 in) wide.

The lobe on the top of the anther is dark blue and brown with a yellow tip and a few short finger-like glands on the back.

[2][3] Thelymitra sparsa was first formally described in 1999 by David Jones from a specimen collected on the plains near Snug and the description was published in Australian Orchid Research.

[4] The specific epithet (sparsa) is a Latin word meaning “strewn", "sprinkled", "flecked" or "spotted",[5] referring to the sparse hairs on the anther's lateral lobes.

[3] The wispy sun orchid is restricted to a few montane sites on the Snug Plains and Wellington Range near Hobart where it grows in low scrub with grasses and sedges.