Definition
Pterostylis recurva is a species of terrestrial orchid in the family Orchidaceae, commonly referred to as the curved greenhood.
Overview
Pterostylis recurva is endemic to southeastern Australia, occurring primarily in the states of New South Wales and Victoria. It inhabits open forest, heathland, and shrubland on well‑drained soils, often in areas with a seasonal moisture regime. Flowering typically occurs in the austral spring, from September to November, after which the plant produces a dry capsule containing numerous minute seeds. Like other members of the genus, it relies on specific mycorrhizal fungi for germination and early development.
Etymology / Origin
The generic name Pterostylis derives from the Greek words pterón (“wing”) and stylos (“column”), referring to the wing‑like lateral extensions of the column in many species of the genus. The specific epithet recurva is Latin for “bent back” or “curved”, describing the pronounced backward curvature of the dorsal sepal that forms the characteristic hood of the flower.
Characteristics
- Growth form: A perennial, deciduous herb arising from an underground tuber.
- Leaves: A basal rosette of 3–6 ovate to lanceolate leaves, each 30–80 mm long and 10–30 mm wide, with a smooth to slightly wavy margin.
- Flower: Typically a single flower per stem, 25–35 mm long. The dorsal sepal and petals are fused to create a galea (hood) that arches forward and then curves backward, giving the species its name. The galea is green with translucent white stripes. The lateral sepals are down‑turned, fused at the base, and bear slender, elongated tips. The labellum is small, dark brown, and concealed within the flower, only becoming visible when triggered by a visiting insect.
- Pollination: The flower is adapted for pollination by small gnats or fungus gnats. When an insect enters the galea, the labellum acts as a trapdoor, briefly holding the insect and ensuring contact with the pollinia before releasing it.
- Fruit: A narrow, cylindrical capsule that matures after flowering and releases dust‑like seeds adapted for wind dispersal.
Related Topics
- Pterostylis (genus) – a diverse group of Australian greenhood orchids.
- Orchidaceae – the orchid family, one of the largest families of flowering plants.
- Australian native orchids – a broader category encompassing the many endemic orchid species found across Australia.
- Mycorrhizal symbiosis – the mutualistic relationship between orchid seeds/tubers and soil fungi essential for orchid development.