Horticulture/Erigeron

Erigeron (syn. Stenactis) is a genus of about 200 species of flowering plants in the family Asteraceae. The genus has a cosmopolitan distribution with the highest species diversity in North America.

The most widely used common name, fleabane, is shared with related plants in several other genera; another common name is summer starwort. The common name is derived from the belief that the dried plants repelled fleas.

Many species are used as ornamental plants, with numerous named cultivars such as 'Wayne Roderick', 'Charity', 'Dunkelste Aller' and 'Foersters Liebling'.

Description
The species are annuals, biennials or perennials. They are well-branched plants with erect stems, characterized by their numerous white, lavender or pink ray flowers and yellow disc flowers. Some members of this group have no ray flowers. The pappus (= modified calyx, forming a crown) is shorter than in Aster, and consists of bristles. The ray florets are narrower than in Aster, but are clearly longer than the involucre (= whorled bracts).

Pests and diseases
Bucculatrix angustata, Coleophora squamosella (which feeds exclusively on E. acris), Schinia intermontana, Schinia obscurata (both of which also feed exclusively on Erigeron), Schinia sexata (which feeds exclusively on E. glabellus) and Schinia villosa.