Experimental Taxonomic Studies on Colobanthus Bartl

Abstract

The Genus Colobanthus. Colobanthus is classified as a member of the family Caryophyllaceae and is placed in the subfamily Alsinoideae because of its free sepals. The generic name, coined by Bartling, is Greek for a docked or curtailed flower and refers to the absence of petals (Wall and Allan, circa 1925). Colobanthus is a small southern hemisphere genus of approximately 29 species and is best represented in New Zealand and South America (Plate 1). The New Zealand species have been the subject of a recent taxonomic revision (Moore, 196l), but as there is no contemporary treatment of the South American species their number is less certain. About a quarter of the species occur in the Subantarctic Zone as defined by Skottsberg (1962). Four species are confined to islands within this zone while three others also occur on neighbouring landmasses. One of these wider-ranging species, C. crassifolius, extends from the Andes of Chile to 68° S. on the Antarctic Peninsula where with two species of Deschampsia (Gramineae) it forms the recent vascular flora of that continent (Skottsberg, 1954). Species occurring outside the Subantarctic Zone are mainly restricted to mountainous regions.