31/10/2021 ….. Spring Sunday of sun orchids

Esperance, Helms Arboretum, Western Australian Orchids

Getting towards the end of the orchid season in the Esperance district, so we decide to go check out the reliable Helms Arboretum (Mud Map SE 35). Prior to this though we have our usual cooked breakfast at the Esperance Bird and Animal Park.

Moving onto the arboretum we first stop along side Plot 23(E) and find some blue sun orchids. Now the tricky bit is naming them as 4 different species flower in the Esperance district. I’m leaning toward the Shy sun orchid (Thelymitra graminea), which grows in woodlands and forests between Perth and Esperance during the months of October and November. They grow up to 350mm in height and have up to 8 flowers in their inflorescences. The colour ranges from dark blue to purple or mauve.

We now move down to the arboretum proper where we hope to find some Leopard orchids in flower. Driving along Boundary X we first come across bee orchids before Deb spies a Leopard orchid (Thelymitra benthamiana) which grows in seasonally moist flats between Northampton and Israelite Bay during the spring months of September through November. Further plants were found flowering along Boundary Z.

The bee orchids also took our attention and we grabbed some photos. From their markings they appear to be the Elegant donkey orchid (Diuris concinna) which grows in moist sites amongst low shrubs between Cape Arid and Fitzgerald River National Park. So a local orchid, which flowers from September to early December.

Moving along we drive down between Plots 85 & 86 as some mignonette orchids were visible from Brockman Road. The Common mignonette orchids (Microtis media subsp. media) grow in scrublands, woodlands and forests between Shark Bay and Eyre. Flowering occurs from September to January with plants growing up to 600mm in height.

We now explore further and locate more of the same, however the sun orchids are larger, with longer inflorescences and more varied in their colour. So I believe they are the Scented sun orchids (Thelymitra macrophylla) which grow in forests and open wandoo woodlands between Perth and Albany, however Florabase shows the Esperance Shire as being a location for this orchid. They flower from August to October and can reach a height of 1000mm with more than 15 flowers per orchid.

It has been a beautiful sunny spring Sunday, so getting out and exploring for orchids was a wonderful way to fill up the morning. However, as Deb starts her shift at 2pm it is time to head home and grab some lunch. Five species found today, with the sun orchids stealing the show, with 2 species from the Blue sun orchid complex and the Leopard orchid, the sole member from the Sienna sun orchid complex. Only 1 month left of spring so we may get to explore for orchids this season, only time will tell.

The orchid below I have not named as the flowers are small, refer blowfly for size comparison, and the stems are reddish coloured and quite thick. Leaves have all been eaten off so no help from them. If anyone can assist with the ID that would be appreciated.