Definition
Caleana terminalis is a species of flowering plant in the orchid family (Orchidaceae), belonging to the genus Caleana. It is commonly referred to as a duck orchid and is endemic to the south‑west region of Western Australia.
Overview
The species was formally described in 2006 by botanists Stephen Hopper and Andrew P. Brown. It occurs in a limited range within the Southwest Australian Floristic Region, typically growing in sandy or lateritic soils on low hills and near granite outcrops. Like other members of the genus, C. terminalis is a terrestrial orchid that produces a single, distinctive flower resembling the shape of a duck in flight.
Etymology / Origin
The generic name Caleana honors the English botanist George Caley (1770–1829). The specific epithet terminalis derives from the Latin word terminalis, meaning “situated at the end” or “terminal”. It refers to the position of the labellum (the specialized petal) which is situated at the distal end of the flower’s column, a characteristic that distinguishes this species from related taxa.
Characteristics
- Growth habit: Deciduous, tuberous perennial herb.
- Leaf: Usually a single, narrow, basal leaf that emerges after flowering; leaf length ranges from 30 to 80 mm.
- Flower: Typically one flower per stem, 20–30 mm long. The flower displays a brownish‑green to reddish‑brown dorsal sepal and lateral sepals that are reflexed. The labellum is hinged and resembles a duck’s head and beak, with a glossy black “eye” spot.
- Column: The column is short, with a distinctive terminal placement of the labellum.
- Pollination: The flower is pollinated primarily by male thynnine wasps, which are attracted by the flower’s visual mimicry and scent, a pollination strategy common to the genus.
- Flowering period: Late spring to early summer (September to November in the Southern Hemisphere).
- Habitat: Open woodland and shrubland on well‑drained soils; often associated with Banksia or Eucalyptus communities.
Related Topics
- Orchidaceae (orchid family)
- Caleana (duck orchids)
- Southwest Australian Floristic Region
- Thynnine wasp pollination
- Australian endemic plant conservation
Note: The information presented is based on peer‑reviewed botanical literature and herbarium records. Where specific details are limited, the description reflects the current consensus among orchid specialists.