whitetops tall flat-topped asters |
|
---|---|
Doellingeria umbellata | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Asterales |
Family: | Asteraceae |
Subfamily: | Asteroideae |
Supertribe: | Asterodae |
Tribe: | Astereae |
Genus: |
Doellingeria Nees |
Synonyms | |
|
Doellingeria is a genus of flowering plants in the aster family. It contains species formerly included in Aster but now considered to be a distinct genus. They are known commonly as tall flat-topped asters or whitetops.
There is still some disagreement as to which species should be included in Doellingeria. Some authorities include up to 10 or 11 species in Doellingeria, but phylogenetic analyses suggest that any Asian plants in the genus should be classified in Aster, making Doellengeria an endemic North American genus. A fourth is now treated as Oclemena reticulata.
Doellingeria as it is now defined is a genus of perennial herbs growing from rhizomes or woody bases. The unbranched stems grow erect and the tallest can reach 200 cm (79 in) in height. The alternately arranged leaves have smooth edges and are sometimes woolly or rough-haired. The flower heads are a few millimeters long and contain 2 to 10 white ray florets, sometimes more. The disc florets are light yellow and the lobes at the tips may spread or curl. The fruit is a cypsela with a pappus of three rings of white or tan bristles and an outer ring of scales.