Erigeron acer, L.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1976, Flora Europaea. Volume 4. Plantaginaceae to Compositae (and Rubiaceae), Cambridge University Press : 118

3. E. acer L. , Sp. Pl. 863 (1753).

Annual, biennial or rarely perennial. Stem 10-60(-100) cm, usually with dense, grey crispate hairs. Basal leaves 2-10 x 0-3-1 cm, narrowly elliptical to obovate, petiolate, entire or rarely slightly serrate. Flowering stems usually erect and solitary, branched above, forming a corymbose or elongate panicle of up to 70 capitula, rarely with one capitulum; cauline leaves numerous, becoming lanceolate and sessile above; upper parts of stem and capitula with short, inconspicuous glandular hairs. Involucral bracts 5-7 mm, linear, with brown centre and scarious margin. Florets trimorphic; ligules scarcely exceeding the tubular florets, lilac. Dry, stony or sandy places. Almost throughout Europe. All except Az BI Cr Fa Is Sa Sb Si?Tu.

Very variable; at least five subspecies can be recognized. 1 Leaves and involucral bracts usually with dense, crispate hairs

(a) subsp. acer 1 Leaves glabrous or subglabrous; involucral bracts glabrous to moderately hairy

2 Involucral bracts with sparse to moderately dense long hairs

(b) subsp. angulosus 2 Involucral bracts glabrous or almost so

3 Involucral bracts uniformly purplish (e) subsp. politus 3 Involucral bracts green, with lilac apex

4 Upper cauline leaves distinctly smaller than the basal; capitula up to 30; ligules scarcely exceeding the involucral bracts (c) subsp. droebachiensis 4 Upper cauline leaves not markedly smaller than the basal; capitula usually 30-70; ligules distinctly longer than the involucral bracts (d) subsp. macrophyllus