Citation: Turcz., Bull. Soc. Nat. Mosc. 24:66 (1851).

Derivation: Greek tri from treis, three; ptilotos, feathered; diskos, a disc; in reference to the 3 plumose pappus bristles of each achene.

Synonymy: Dimorpholepis A. Gray, Hook. Ic. 9: t. 856 (1852); Hooker's J. Bot. Kew Gard. Misc. 4:227 (Aug. 1852); Duttonia F. Muell., Linnaea 25:410 (1853).

Common name: None

Description:
Annual herb with non-glandular vestiture; leaves cauline, alternate, sessile, entire.

capitula sessile, terminal on short branches, solitary or 2 or 3 together, usually surrounded by a cluster of leaves, heterogamous, discoid; involucre hemispherical to subglobular, several-seriate, never radiating; outer bracts wholly scarious, pale-stramineous; inner bracts curved, stiff, subherbaceous, glandular-hairy, with erect scarious tips; receptacle conical, naked; florets exceeding the involucre and overhanging it, numerous, mostly bisexual and 4-merous except for a few of the outer ones which are female and 3-merous; corolla tubular, slightly dilated towards the limb, yellow; anthers tailed at the base; style branches linear, somewhat flattened, with a truncate papillose apex.

Achenes oblong-ellipsoid, sparsely pubescent; pappus of 2 or 3 broad flat plumose-ciliate bristles; pappus of female florets reduced, sometimes to a jagged cup.

Biology: Monotypic; endemic in Australia.

Taxonomic notes: Because of the feathery pappus, generally included in Helipterum, but distinct from most Australian species assigned to that genus in several features, including the heterogamous capitula, with florets exceeding and overhanging the involucre. More likely close to Leptorhynchos and some Helichrysum species, showing considerable similarity to L. waitzia, but distinct from all of these in the exceptionally broad ciliate pappus bristles and the sessile heads each surrounded and exceeded by a cluster of leaves.

Author: Not yet available