Thelymitra latifolia
R.J.Bates Flat-leaf Sun-orchidFlowering stem erect, straight, 10–30 cm tall, 2–4 mm wide, glaucous, green with pink or purplish tints. Leaf linear-lanceolate, 5–10 cm long, 5–15 mm wide, obliquely erect, leathery, blade flat, ribbed abaxially, not sheathing the scape or sheathing only at extreme base, dark green with a purplish base. Inflorescence 2–8-flowered, open. Sterile bracts usually 2 linear lanceolate 2–5 cm long, closely sheathing except at the acuminate free apex, green with purplish tints sometimes glaucous. Perianth segments ovate to obovate, concave, 6–10 mm long, pale to mid-blue sometimes mauve or pink. Column 5–6 mm long, pale pink; mid-lobe hooding the anther, 3–4 mm long, tubular, curved gradually, yellow and brown or predominantly yellow including the apex, which is not or slightly notched rather than gaping, lightly ribbed longitudinally with somewhat crenulate margins; auxiliary lobes often present as two short thick spurs on lower apical margins; lateral lobes converging 1.2–1.5 mm long, porrect at base, curving gently upwards and forwards with a sub-terminal, elongated, mop-like, untidy tuft of white trichomes, which are held well in front of the post-anther lobe, often drying a dirty colour. Anther inserted above centre of column, ovoid 1.6–1.8 mm long, the connective extended into an apical beak. Flowers mid Oct.- early Nov.
Also South Australia. Until very recently known only from South Australia. Relatively widespread Victoria (based on iNaturalist observations identified by Robert Mitchell) where known from the Little Desert, Minimay area, Grampians, Bendigo, Brisbane Ranges and extending east to Yering Gorge. Backhouse (2019) notes that the species was confirmed in Victoria in 2017 from near Inglewood, Casterton and Dergholm. However, the species is represented at the National Herbarium of Victoria by a single 1998 collection from the Grampians. Grows in woodland on sandy to heavier gravelly soils (Backhouse 2019).
Thelymitra latifolia resembles T. peniculata and other members of the T. pauciflora complex, but is distinguished by a relatively broad, flat leaf with its sinus at or almost at ground level. The perianth segments are pale to mid blue or mauve, 6–10 mm long and open briefly and only in warm humid weather. The column resembles that of T. peniculata, but the post-anther lobe is not dilated and not or barely cleft.
Bates, R.J. (2010). The Thelymitra pauciflora R.Br. complex (Orchidaceae) in South Australia with the description of seven new taxa. Journal of the Adelaide Botanic Gardens 24: 17–32.
Backhouse, G. (2019). Bush Beauties: the wild orchids of Victoria, Australia. Gary Backhouse, Melbourne, Australia.