Diuris chrysantha

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Diuris chrysantha, known as the granite donkey orchid, is a tuberous, perennial orchid native to eastern Australia. It usually has one or two leaves and a flowering stalk that bears two to seven deep golden to orange flowers with brown markings. It grows on the ranges and tablelands north from Tamworth to the Darling Downs.

Description
This orchid has one or two linear leaves, about 120–360 mm long and 4–8 mm wide. The flowers are about 18–20 mm wide and sit on a stem 150–320 mm tall. The dorsal sepal is erect and egg-shaped, about 7–9 mm long and 6–7 mm wide. The lateral sepals are linear to spatulate, 12–18 mm long and 2–4 mm wide, and they hang downward. The petals are almost circular, 6–8 mm long, on a brown stalk 4–7 mm long, held above the rest of the flower. The lip (labellum) is 7–9 mm long with three lobes: the center lobe is heart-shaped to wedge-shaped, 5–7 mm long and 4–6 mm wide, and the side lobes are egg-shaped, 2.5–4 mm long and 2.5–3 mm wide. There are two callus ridges on the labellum, each 2–3 mm long, spreading apart near the mid-line. Flowering occurs from August to November.

Taxonomy and naming
Diuris chrysantha was first formally described in 1987 byDavid L. Jones and Mark A. Clements from a specimen collected near Stanthorpe, Queensland. The name chrysantha comes from Greek words chrysos meaning “gold” and anthos meaning “flower.”

Distribution and habitat
Granite donkey orchid grows in grassy forest on the ranges and tablelands north from Tamworth to the Darling Downs in eastern Australia.

Synonyms
Historically, this species has been referred to as Diuris sp. (Jollys Falls J. Loveday), Diuris sp. aff. chrysantha (North Coast), and has been associated with Diuris aurea in older usage.