Danthonia is a genus of perennial grasses belonging to the family Poaceae (order Poales), commonly known as oatgrasses, heathgrass, or wallaby grass. The genus was named in honor of E. Danthoine, a French botanist. Members of the genus are characteristically tufted, cool-season perennial grasses with narrow, often involute leaves and spikelets bearing awned lemmas typical of the subtribe Danthoniinae.
The genus in its current circumscription comprises roughly 20–30 species native to Eurasia, North Africa, and the Americas, with a range spanning Europe, Turkey, the Caucasus, North and South America. A broad array of species formerly treated under Danthonia—particularly the Australian and Southern Hemisphere contingent—have been transferred to related genera such as Rytidosperma, Chionochloa, Joycea, Notodanthonia, Merxmuellera, and others, substantially narrowing the genus. Notable members still retained in Danthonia include D. californica (California oatgrass) of western North America and Chile, D. intermedia (timber oatgrass) of western North America and the Russian Far East, D. sericea (silky oatgrass) of the eastern United States, D. alpina of central and southern Europe, and D. araucana of Chile. The genus has a basic chromosome number of x = 6 or 9, with both diploid species and polyploid series (2n = 18, 36, 48) reported.
Etymology
The genus Danthonia was named in honor of E. Danthoine, a French botanist. The name was formally applied by the Swiss botanist Augustin Pyramus de Candolle in the early nineteenth century.
Distribution
Danthonia is distributed across Eurasia, North Africa, and the Americas. In Europe, species such as D. alpina and D. decumbens occur from the British Isles and Scandinavia south to the Mediterranean and east to the Caucasus. In the Americas, the genus is represented from western and eastern North America southward through the Andes and southern South America, including Chile and Argentina. Australian species formerly included in Danthonia have since been reclassified into the genus Rytidosperma.
Taxonomy Notes
As currently circumscribed, Danthonia belongs to the family Poaceae, order Poales (class Liliopsida, phylum Tracheophyta). The genus has undergone substantial taxonomic revision; a large number of species formerly placed here are now assigned to Amphibromus, Astrebla, Chionochloa, Joycea, Karroochloa, Merxmuellera, Monachather, Notodanthonia, Plinthanthesis, Rytidosperma, and Schismus. The cytology of the genus shows a basic chromosome number of x = 6 or 9, with diploid and polyploid series (2n = 18, 36, 48).
