Thelymitra colensoi, commonly called Colenso's sun orchid, is a species of orchid in the family Orchidaceae that is endemic to New Zealand. It has a single fleshy, channelled leaf and up to seven pale blue or mauve to pink flowers. It is similar to T. pauciflora but is smaller and less robust than that species.
Thelymitra colensoi is a tuberous, perennial herb with a single fleshy, channelled, linear to lance-shaped leaf NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. Up to seven pale pale blue or mauve to pink flowers NaNsigfig=1NaNsigfig=1 wide are borne on a flowering stem NaNsigfig=1NaNsigfig=1 tall. The sepals and petals are NaNsigfig=1NaNsigfig=1 long and NaNsigfig=1NaNsigfig=1 wide. The column is pale blue to mauve about 4sigfig=1NaNsigfig=1 long and 2sigfig=1NaNsigfig=1 wide. The lobe on the top of the anther is dark brown to reddish brown with a bright yellow tip. The side lobes bend sharply upwards and have sparse, brush-like white hairs. Flowering occurs from July to December but the flowers are usually self pollinating and only open in very hot, still weather.[1] [2]
Thelymitra colensoi was first formally described in 1864 by Joseph Dalton Hooker from a specimen collected by William Colenso and the description was published in Handbook of the New Zealand Flora.[3] The specific epithet (colensoi) honours the collector of the type specimen.
Colenso's sun orchid grows in shrubland, forest and in pine plantations. It frequently grows with the larger flowered, more robust T. pauciflora and sometimes grows in gardens to which pine bark has been added. It is found on the North, South, Stewart, and Three Kings Islands.