By Noel Rosten Reviewed by Wendy Grimm Australian Plant Society
Orchids are herbaceous plants. More than thirty species have been found in the Park. At least seven species use trees or rocks as hosts (epiphytes). They use their host only as support, not for food. The remainder are orchids that grow in the ground (terrestrials). Spring is the main flowering time but every month will find one or two in bloom.
Large Tongue orchids
Two species are found in the Park, Tartan Tongue Orchid Cryptostylis erecta and Large Tongue Orchid Cryptostylis subulata. These are ground orchids. The erect lanceolate leaves grow from underground stems. From the base
of the leaves the flowers arise on erect stalks.
Cryptostylis erecta has a pale hooded flower with many red veins. It blooms in November–December.
Cryptostylis subulata has a 20-30 mm tongue-like flower, yellow-green with red towards the tip. In October–November the scent of this flower fools male wasps into mating with it (pseudocopulation), thereby fertilising the next orchid they visit.
Dotted Sun Orchid
The ground orchids Thelymitra are found in sunny spots in the spring. They are called sun orchids as the flowers open fully only in bright sunlight. Blooms are pale blue to purple, up to nine to each stem rising from a single basal leaf. Each flower has many dark spots towards
the centre, and the name has been taken from the South African Blue-flowered Corn Lily Ixia.
Two species, Waxlip Orchid Glossodia major and Small Waxlip Orchid Glossodia minor, occur in the Park.
Glossodia major is larger in all parts. The flower is purple with a white spot in the centre. The single bloom arises from a stem with a single hairy leaf.
Glossodia minor is similar, but without the white spot. It is smaller, and the flower is pinkymauve. Both species flower in spring.
The large swollen stems of Dendrobium speciosum have dark-green broad leathery leaves 100-300 mm long at the top. These have beautiful long sprays with many yellow to white blooms in August and September. Once
common in the Park, Dendrobium speciosum is now rare owing to the activities of collectors. Those that remain are found in inaccessible
places on cliffs, usually facing east.
The Tongue Orchid is very common, growing on rocks in shady places in the valley. Its leaves are thick, tongue shaped, and able to store moisture; in dry weather they shrivel until the next rain. The small white flowers are in sprays of up to twenty, and occur in late September and October.
The orchid Cymbidium suave with its straplike leaf clumps grows from hollows high in trees. Its roots feed off the rotten wood, and travel a long way. Hanging sprays of fragrant green flowers develop in October and
November. While these plants usually grow on eucalypts they have also been found on Allocasuarina.
Copeland, L.M. & Backhouse, G.N. 2022, Guide to Native Orchids of NSW and ACT, CSIRO Publishing, Clayton South.