Star Orchid
Thelymitra stellata
Notes
The Star Orchid is one of the most magnificent Sun Orchids of Australia and unfortunately also one of the rarest. It is known from only a few small, scattered populations in south-western WA where it is found mostly along the western edge of the Darling Scarp in the vicinity of Perth and between Chittering and Three Springs in the Mid West region and adjacent north-western Wheatbelt. On the Darling Scarp it grows in gravelly and lateritic soils amid low shrubs in Jarrah and Wandoo woodland, while the northern populations are found in low heath on lateritic hilltops. The peak flowering period ranges from mid October in the north to early November near Perth.
The Star Orchid is easily recognised by its overall brown flowers with extended yellow blotches and stripes. As with many Sun Orchids, the flowers will only open on warm and sunny days and otherwise remain closed. The single, broad leaf sits at the base of the flower stem and looks similar to that of other species of Sienna Sun Orchid, including the common and widespread Leopard Orchid (Thelymitra benthamiana).
Several similar-looking species of Sienna Sun Orchid exist across south-western Australia. Some of them were originally considered as varieties of the Star Orchid, but have since been established as separate species. One of these is the Crystal Brook Star Orchid (Thelymitra magnifica) which is also found along the western edge of the Darling Scarp near Perth and is characterised by a slightly earlier flowering period and somewhat larger and darker flowers. Other similar species include Jackson’s Sun Orchid (Thelymitra jacksonii) which occurs along WA’s south coast between Albany and Manjimup, and the York Sun Orchid (Thelymitra yorkensis) which is restricted to Wandoo woodland between York and Beverly in the western Wheatbelt. Like the Star Orchid, all of these species are extremely rare and restricted to a small geographic area.
Photos
References
- Thelymitra stellata in the Australian Plant Name Index
- Thelymitra stellata in the Atlas of Living Australia
- Thelymitra stellata in the Western Australian FloraBase