Genoplesium plumosum | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Angiosperms |
Clade: | Monocots |
Order: | Asparagales |
Family: | Orchidaceae |
Subfamily: | Orchidoideae |
Tribe: | Diurideae |
Subtribe: | Prasophyllinae |
Genus: | Genoplesium |
Species: | G. plumosum |
Binomial name | |
Genoplesium plumosum (Rupp) D.L.Jones & M.A.Clem. |
Genoplesium plumosum, commonly known as the Tallong midge-orchid or plumed midge-orchid, is a species of orchid endemic to New South Wales. It is a small orchid only known from a few sites near the towns of Tallong and Wingello on the Southern Tablelands and is only relatively easy to find for about a month, when it flowers. It has been classified as "Endangered" under the EPBC Act.
Genoplesium plumosum is a terrestrial, perennial, deciduous, sympodial herb, usually with a few inconspicuous, fine roots and a pair of more or less spherical tubers. The tubers are partly covered by a protective fibrous sheath which extends to the soil surface. There is a single cylindrical, leaf fused to the flowering stem. The leaf is 10–20 cm (4–8 in) long and the part which is free from the stem is 15–30 mm (0.6–1 in) long and ends below the flowers. The leaf of flowering plants is solid but the leaves on plants without flowers are hollow.
The inflorescence is a spike 10–30 mm (0.4–1 in) tall, with between one and eight, non-resupinate flowers. The flowers are more or less , moderately crowded, 8 mm × 5 mm (0.3 in × 0.2 in), greenish with purple stripes and have a purplish-red labellum. The sepal is narrowly egg-shaped, 6–7 mm (0.2–0.3 in) long, about 3 mm (0.1 in) wide, dished on the lower surface with smooth edges and a pointed tip. The sepals are linear to lance-shaped, 7.5–9 mm (0.3–0.4 in) long, about 1 mm (0.04 in) wide and diverge from each other. The petals are narrow egg-shaped, 5.5–6.5 mm (0.2–0.3 in) long, about 1.5 mm (0.06 in) wide with a long, pointed tip. The labellum is above the column and stiffly hinged to it, and is oblong, about 5 mm (0.2 in) long, 2 mm (0.08 in) wide with hairy edges and a pointed tip. The callus is narrow egg-shaped to lance-shaped and extends nearly to the tip of the labellum. Flowering usually occurs 4 to 6 weeks following summer or autumn rainfall. The fruit is a non-fleshy, dehiscent capsule containing hundreds of seeds.