Doellingeria umbellata

Tall Flat-topped White Aster, Parasol Whitetop Aster, aster à ombelle

Doellingeria umbellata (Mill.) Nees is native to much of the eastern deciduous forest area and adjacent boreal forest in eastern North American from Alberta to Newfoundland south to northern Georgia.  Plants range in size from small 0.5 m tall shoot with few heads to large 2 m tall plants with large inflorescences with 100-150 heads. Semple, Chmielewski and Leeder (1991) included dot distribution maps of the two races. The species is diploid 2n=18 throughout its range.

Two varieties are recognized (Semple and Chmielewski 2006 FNA) based on differences in hair density on the undersides of the stem leaves:

•     var. pubens (leaves with abaxial faces densely puberulent (more than 12 hairs/mm ²; northern Ontario, southern Manitoba (disjunct to Alberta) south to Nebraska, Iowa, Illinois)
•     var. umbellata (leaves with abaxial faces sparsely piloso-villous, fewer than 10 hairs/mm ² ; Newfoundland to Minnesota, south to northern Alabama and Georgia)