#1513-1519 - Orchids of the Wheatbelt
#1513 - Pterostylis sargentii - Frog Greenhood
One of the many orchids we saw while we were out at the Dryandra Woodlands and another area of surviving woodland in the WA Wheatbelt.
Greenhoods are common in the wheatbelt of WA, and this species often grows on and around rocky breakaways and under Wandoo trees in deep leaf litter. In this case they were growing in litter underneath Mallet (Eucalyptus astringens) which was a bit surprising since shed Mallet bark suppresses nearly all plant growth. Each plant has up to six flowers and grows to almost 20cm tall. They flower from July to early September.
#1514 - Pterostylis sanguinea - Red-banded Greenhood
Another Greenhood, endemic to southern Australia, and common and widespread in Western Australia, South Australia, Victoria and, rarely, in Tasmania. The plants either have a rosette of leaves when not flowering or stem leaves on a spike in the years they flower. Like here, they have up to about twelve flowers which are dark reddish-brown, sometimes green or green and brown.
The translucent windows in the hood are part of the trap they use for pollinating fungus gnats in the genus Mycomya. The gnats are attracted by chemicals secreted by the labellum and enter the flower looking for a non-existent female, whereupon the labellum moves forward, trapping the insect between the column wings, the labellum and other flower parts. The gnat blunders around trying to escape, picking up pollinia or transferring pollinia they acquired at another flower.
Yilliminning Rock, near Narrogin, Western Australia
#1515 - Caladenia falcata - Fringed Mantis Orchid
A species in the Green Spider Orchid subgenus of Caladenia, and relatively common here in the SW. It grows in woodland, shrubland or near granite outcrops, and in this case all three at once, since it was growing under scrubby she-oak trees near Yilliminning Rock.
#1516 - Caladenia integra -Smooth-lipped Spider Orchid
Much more rare than the Mantis Orchid I just posted, even though though this one was growing a foot away, and was growing in comparative abundance under the she-oaks on top of Yilliminning Rock. Under she-oaks, on granite, is its usual habitat, which may explain why it’s a threatened species and most populations are isolated.
#1517 - Caladenia hirta subsp. rosea - Pink Candy Orchid
Another common and widespread orchid in woodlands and on soil over granite, endemic to SW Australia. First described by John Lindley in 1840, in ‘A Sketch of the Vegetation of the Swan River Colony’.
Yet another species we saw at Yilliminning Rock.
#1518 - Caladenia chapmanii - Chapman’s Spider Orchid
Red, Yellow and Cream forms, all on and around Yilliminning Rock.
Like other Caladenias a terrestrial, perennial, deciduous, herb, often growing in large groups, from underground tubers with a single erect, hairy leaf. First described in 2001, but first recognised as a new species in 1940. Found in scattered populations in woodland in the SW, but not considered threatened.
#1519 - Diuris porrifolia - Small-flowered Donkey Orchid
One of the few orchids in flower at Yilliminning Rock that wasn’t a Caladenia, although there were a number that weren’t in flower, and a few Greenhoods I’ve covered before.
Duiris porrifolia used to be called the Western Wheatbelt Donkey Orchid, but recently the species got split into two, with D. brachyscapa keeping the common name, and D. porrifolia getting a new common name. This seems odd to me, but no doubt they had their reasons