Thelymitra aristata Lindl.

Plant Growth Form

Thelymitra aristata Lindl. is a tuberous perennial herb.

Leaf Morphology

It produces a single thick, fleshy, channelled leaf that ranges from linear to lance-shaped, measuring 250–400 mm (10–20 in) long and 25–40 mm (1–2 in) wide.

Flower Arrangement

Between six and forty pale blue, deep blue, or purple flowers, each 30–40 mm (1–2 in) wide with darker veins, are crowded on a flowering stem that grows 300–1,000 mm (10–40 in) tall. There are three to five large bracts along the flowering stem.

Sepal And Petal Size

Its sepals and petals are 15–20 mm (0.6–0.8 in) long and 6–7 mm (0.2–0.3 in) wide.

Central Column Morphology

The central column of the flower is cream-coloured, white, or pale blue, 6–7 mm (0.2–0.3 in) long and 5–5.5 mm (0.20–0.22 in) wide. The lobe on top of the anther is purplish brown with a finely toothed yellow tip, and the side lobes have dense, mop-like tufts of white hairs.

Flower Physiology

The flowers are scented, insect-pollinated, and only open on sunny days.

Flowering Period

Flowering occurs between September and January.

Common Name And Habitat

This species, commonly called the great sun orchid, grows in a wide range of habitats, from swamp margins to open forest.

Geographic Distribution

It is distributed in coastal and near-coastal areas of New South Wales south of Fitzroy Falls, the southern half of Victoria, south-eastern South Australia, and Tasmania including King Island and Flinders Island.