Description: Saprophytic herbs, almost entirely subterranean, with only the flowers, fruit and involucral bracts emerging above the soil surface, sympodial; roots absent; [tuberoids sometimes present].
Leaves scale-like, cauline and forming an involucre below the inflorescence.
Inflorescence a dense terminal capitulum; flowers not resupinate. Sepals and lateral petals forming a short, curved, hood-like tube. Dorsal sepal basally fused to, and shorter than, lateral sepals. Lateral sepals basally fused. Lateral petals fused basally to column, slightly shorter than dorsal sepal. Labellum hinged to column foot, not lobed, densely [or sparsely] papillose. Column lacking free filament and style; column wings fused to column, expansive in upper half as narrow-triangular (ear-like) lobes. Column foot vestigial. Anther erect, parallel to the axis of the column, persistent. Pollinia 2, granular. Stigma entire. Rostellum not prominent, ventral.
Fruit a reddish berry. Seeds crustose, not winged.
Distribution and occurrence: World: 5 species, endemic to Australia: Qld, N.S.W., W.A.
Text by PH Weston, updated by Matt A.M. Renner (31 July 2020). Key reproduced from Clements and Jones (2020) Lankesteriana 20: 221-227.
| ||Key to the species|| |
|1||Sheathing bracts 7–8 mm long, sepals 3–4 mm long with an apical point 0.5–1.5 mm long||Rhizanthella slateri|
|Sheathing bracts 16–18 mm long, sepals 6.5–10.0 mm long with an apical point 3–5 mm long||2|
|2||Apex of lateral sepals caudate, densely papillate, labellum narrowly elliptical, dark red without pale central band, margins with numerous short siliceous trichomes||Rhizanthella omissa|
|Apex of lateral sepals filiform, smooth, labellum cordate, dark purple-black with pale central channel, margins with few short siliceous trichomes|
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