Overview
Harrington’s Spider Orchid (Caladenia harringtoniae), also frequently called the Pink Spider Orchid, is a delicate and threatened terrestrial orchid endemic to the high-rainfall forests of southwestern Australia. Flowering in late spring as winter floodwaters recede, this species is immediately recognized by its soft pink to creamy-rose floral segments and gracefully drooping filamentous tips.
Biology and Physical Characteristics
Caladenia harringtoniae produces an erect, hairy linear leaf that emerges during early winter rains. Between October and December, it sends up a tall, slender stem bearing one to three sweetly scented, pale-pink flowers. The sepals and petals are widely spreading and terminate in slender, non-clubbed glandular filaments. The labellum is small, three-lobed, with short blunt teeth along its margins and two rows of glossy, dark reddish calli running down its midline.
Behavior and Ecology
Inhabiting moisture-retaining soils along drainage systems, Caladenia harringtoniae relies on native thynnid wasps for pollination via pseudocopulation. Unlike drier-habitat spider orchids that bloom early in spring, this species delays flowering until late spring and early summer when surrounding seasonal swamp beds dry sufficiently for pollinating insects to navigate the dense understory.
Conservation and Human Impact
Federally listed as Vulnerable under the Australian EPBC Act, Harrington’s Spider Orchid has suffered historical population losses due to agricultural clearing, salinization of freshwater drainage flats, and feral pig rutting. Current recovery actions overseen by Western Australia’s Department of Biodiversity, Conservation and Attractions (DBCA) involve fencing known swamp colonies, controlling invasive blackberry thickets, and strictly managing prescribed fire intervals.
Interesting Factoid
Named in honor of Kerry Harrington, who first brought the taxon to botanical prominence in the 1980s, this orchid is one of the few Caladenia species whose blooming window routinely extends into December.
Last updated: October 2026