Coronidium rupicola

Coronidium rupicola, commonly known as the yellow button,^[1] is a flowering plant in the family Asteraceae. It is a small, upright, perennial shrub with yellow flowers borne on a single stem and is endemic to Queensland, Australia.

Yellow button
Conservation status
Least Concern (NCA)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Asterales
Family:	Asteraceae
Genus:	Coronidium
Species:	C. rupicola
Binomial name
Coronidium rupicola (DC.) Paul G. Wilson[2][3]
Synonyms[3]
Homotypic Helichrysum rupicola DC. Heterotypic Gnaphalium endeavourense Sch.Bip. Gnaphalium rupicola Sch.Bip. Helichrysum collinum DC. Helichrysum rupicola var. danesii Domin

Description

Coronidium rupicola is a small, shrubby, erect perennial with a single stem and terminal yellow button flower-heads about 2 cm (0.79 in) in diameter. Unlike other species of Coronidium it doesn't have conspicuous, large bracts, instead a ring of smaller, narrow light-coloured bracts. The florets are thickly crowded with a greenish centre. The flowers in bud are thickly covered with long, whitish hairs, new growth stems silvery and woolly. The leaves are narrow, lanceolate, 5 cm (2.0 in) long, pale green, densely woolly underneath, upper surface smooth, margins rolled under and wavy. Flowering occurs throughout the year and the fruit is a cypsela.^[4]

Taxonomy

This species was first described in 1838 by Augustin Pyramus de Candolle as Helichrysum rupicola.^[5] In 2008 Paul Graham Wilson published a paper titled "Coronidium, a new Australian genus in the Gnaphalieae (Asteraceae)", in which he erected the new genus Coronidium and transferred this species to it. It was published in the journal Nuytsia.^[6][2]

Etymology

Wilson coined the genus name Coronidium from the Greek words korone (crown) and the diminutive -idion, a reference to a feature seen on the fruit after bristles have broken away from it.^[6]: 301 The specific epithet rupicola is derived from the Latin words rūpēs meaning "cliff", and -cola meaning "to inhabit", and is a reference to the habitat where this species is found.^[7]

Distribution and habitat

Yellow button is endemic to Queensland and grows on rocky coastlines, road verges, woodland and exposed ridges.^{[4][6]: 306}