Erect perennial herb to 1.5 m tall, hairy. Stems branched above. Leaves along stems, to 12 cm long, entire, base stem-clasping, hairy. Capitula about 4 cm across, in dense panicles; autumn. Ray florets deep purple. Disk florets yellow.
E North America
Widely cultivated as an ornamental and available as a range of cultivars including: 'Barr's Pink' with pink flowers; and 'Harrington's Pink', growing over 1 m tall with pink flowers.
Other shrubby species with capitula in groups are:
A. amellus L. subsp. amellus, Italian Aster, European Michaelmas Daisy, from Europe and WAsia, a herb to 70 cm tall with large showy capitula (to 5 cm across), usually with purple ray florets;
A. amellus subsp. ibericus (Steven) Avet. from Asia Minor and the Caucasus, which differs in having dark blue ray florets - 'Violet Queen' is similar to the species ['Veilchenkönigin'];
A. cordifolius L., Blue Wood Aster, from E North America, a herb to 1.5 m tall with smallish capitula (to 2 cm across), with pale blue ray florets - 'Silver Spray' has feathery leaves and pale violet-blue flowers;
A. divaricatus L. from E USA, a rhizomatous herb to 60 cm tall with smallish capitula (to 2.5 cm across) and white ray florets;
A. dumosus L. from SE USA, a herb to 1 m tall with small capitula (about 12 mm across) and lavender, blue or white ray florets;
A. ericoides L., Heath Aster, from C and E USA, a herb to 1m tall with small capitula (to 12 mm across) and white or sometimes blue or pink ray florets;
A. ×frikartii hort. (A. amellus L. × A. thomsonii C.B. Clarke) of garden origin, a herb to 70 cm tall with many large capitula (to 5 cm across) terminating the branches and pale violet-blue ray florets, 'Mönch' has pale blue flowers;
A. laevis L. from N America, a herb to 1 m tall with smallish capitula (to 2.5 cm across) and blue to violet ray florets;
A. lateriflorus (L.) Britton from N America, a herb to 1m tall with small capitula (to 1.5 cm across) and white ray florets, the ends often purple - 'Horizontalis' has wide-spreading branches;
A. savatieri Makino from Japan, a herb to 1 m tall with large capitula (to 4 cm across) and bluish purple or white ray florets [Gymnaster savatieri (Makino) Kitam.];
A. sedifolius L. from Europe, a herb to 1.2 m tall with medium-sized capitula (to 3 cm across) and blue to pink ray florets or sometimes without ray florets;
A. umbellatus Mill. from E North America, a rhizomatous shrub to 2 m tall with small capitula (to 18 mm across) and white ray florets.
Source: (2002). Asteraceae. In: . Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press. (as Aster novae-angliae)
