This section is from the book "Sub-Alpine Plants Or Flowers Of The Swiss Woods And Meadows", by H. Stuart Thompson. Also available from Amazon: Sub-Alpine Plants: Or, Flowers of the Swiss Woods and Meadows.
Leaves alternate, much divided or rarely simple Flower-heads small, in a terminal corymb with white or pink rays and a yellow disk. Involucres ovoid or hemispherical, the bracts imbricated, slightly scarious at the edges. Receptacle small, not convex. Achenes without any pappus.
A considerable European and West Asiatic genus.
Stem erect, 3-8 inches high, leafy, and, like the leaves, covered with a grey felt of silky hairs, bearing at the summit a cluster of capitula in a corymbose cyme. Leaves obovate-lanceolate or wedge-shaped, simply pinnatifid, with linear teeth. Ray-flowers 6-8, as long as the involucre, or longer. Capitula large; involucral bracts with a black margin; ray white; disk greenish yellow.
On rocks and debris of the calcareous Alps; 5000-7000 feet.
Common (in the Eastern Alps) and sometimes descending the valleys.
Eastern and Central Alps. In Switzerland only on Monte Generoso.
Stems 1-2 feet high, erect, glabrous, branched only at the top. Leaves broadly linear, regularly serrate. Flower-heads few, in a loose terminal corymb. Involucres hemispherical, rather cottony, larger than in the Milfoil. Ray-florets from 10-15, short, broad, white; disk-florets numerous, interspersed with linear scales.
Damp, hilly pastures, becoming a mountain plant in Southern Europe, where, e.g. on the Col des Montets on the Franco-Swiss frontier it ascends to 5000 feet. August, September.
Most of Europe, except the Mediterranean region, Russian Asia. Britain.
Leaves rather villous, especially on the back, or sometimes glabrous. Lobes linear-lanceolate, Flowers white or often pink, especially in the mountains. Very variable and with one or two named varieties. The writer has seen this well-known plant above 8000 feet in the French Alps.
Roadsides and grassy places. June to August.
Europe and Russian Asia to the Arctic Circle, North America. British.
A. setacea W. et K. is an Alpine variety with smaller, dirty white flowers and setaceous leaf-segments. (Dry hills).
A stout plant 1-2 1/2 feet high, with pubescent stems and leaves. Stem-leaves sessile, auricled at the base, oblong-lanceolate, bi-pinnate, with very numerous segments, which are linear, mucronate. Capitula glabrous and often nodding. Closely allied to the Milfoil and to A. dentifera DC, which grows in the Western Alps of France and Italy.
Pastures and woods in the mountains; scarce. July to September.
Western Alps, Switzerland, Italy, Carniola.