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.
A tall purple-flowered woodland plant. Stems much-branched, glabrous like the whole plant. Capitula small, numerous, few-flowered. Involucral bracts in one row, few. Pappus-hairs simple. Leaves cordate-amplexicaul, bluish green beneath.
Mountain woods, especially in the Conifer zone. July, August.
Eastern, Central, and Western Alps; Pyrenees, Corsica, Vosges, Cevennes. Central and Southern Europe.
The drawing shows merely one small branch, the complete plant being usually 4-5 feet high.
Flowers yellow or blue. Capitula usually small, few-flowered, corymbose. Involucral bracts in several rows. Pappus of many soft feathery hairs. Fruit beaked.
Capitula large, blue, on long stalks. Involucral bracts cordate. Stem very thick, 10-18 inches high, glabrous, branched. Leaves pinnatifid, with narrow segments; upper ones lanceolate.
Sunny rocks and hillsides up to 4500 feet, especially on limestone; local. May to July.
Central and Southern Europe.
The four English species, with yellow flowers, are sometimes seen in the lower hills of Switzerland, viz. Lactuca muralis Fresn., leaves lyrate-pinnatifid; common in woods and under walls. L. virosa L., leaves bristly beneath; waste places. L. Scariola L., leaves less prickly, capitula smaller; stony places. L. saligna L., leaves scarcely ever bristly, linear, entire, arrow-shaped; capitula sessile, crowded; flowers pale yellow. Occasional in Western Switzerland.
Involucral bracts in several rows, few. Flowers blue. Fruit beaked, with a crest of bristles. Pappus-hairs soft, slender, silvery. Tall, robust herbs.
Stem 2-4 feet high, purplish, glandular-hairy at the top, branched and leafy. Inflorescence a dense corymb. Leaves glabrous, except on. the dorsal nerve, lyrate-pinnatifid, the last segment broadly triangular and very large, amplexicaul and acutely auricled. Involucral bracts in several rows, few. Flowers blue or light purplish blue. Fruit beaked with a crest of bristles. Pappus-hairs soft, slender, silvery.
Alps, Pyrenees, Jura, etc. Central and Northern Europe as far north as Scandinavia and the Scotch Highlands.
Stem 2-5 feet high, erect, green, glabrous, branched near the top into a loose umbellate cyme. Leaves glabrous, like the whole plant, lyrate-pinnatifid, with very deep segments, amplexicaul, with broad, rounded auricles. Flowers blue, larger than in alpinum. Achenes greyish, elliptic, compressed, with 5 ribs on each face. Capitula few, shortly stalked.
Similar situations, but much less common than the last.
Western Switzerland, Vosges, Black Forest, Western Alps (of Savoy and Dauphine), Cevennes, Pyrenees. Spain.