Diuris aequalis

Diuris aequalis is a tuberous, perennial herb, grown to a height of 20–45 cm (8–20 in). There are two linear leaves arising from the base of the plant, each leaf 10–20 cm (4–8 in) long, 3–4 mm (0.1–0.2 in) wide and rolled so that the sides of the leaf face each other. There are about two and five golden-yellow to orange flowers arranged on a raceme, usually without spots, each about 25 mm (1 in) wide. The dorsal sepal is broadly egg-shaped to almost circular, 7–10 mm (0.3–0.4 in) long, 8–15 mm (0.3–0.6 in) wide above the flower. The lateral sepals are linear to lance-shaped, 8–13 mm (0.3–0.5 in) long, 2–3 mm (0.08–0.1 in) wide, sickle-shaped and green. The petals are erect, ear-like above the flower, 6–10 mm (0.2–0.4 in) long and 4–6 mm (0.2–0.2 in) wide. The labellum is 5–9 mm (0.2–0.4 in) long, 2.5–5 mm (0.1–0.2 in) wide and has three lobes, the medial lobe ridged in its centre and has two broad calli about 3.5 mm (0.1 in) long. Flowering occurs between October and December, following which the leaves die back to be replaced prior to the next flowering.^[3][4]

Diuris aequalis was first formally described in 1876 by Robert D. FitzGerald in his book Australian Orchids from an unpublished description by Ferdinand von Mueller.^[5][6] The specific epithet (aequalis) is a Latin word meaning "like", "same" or "uniform".^[7]