PRIMULACE^E 209 



TRIENTALIS L. 

 Trientalis europcea L. Chickweed Wintergreen. 



Stem erect, simple, 3-6 inches high, with a whorl of 5 or 6 leaves 

 at the top, which are obovate or lanceolate, usually pointed, 1-2 

 inches long, and with 2 or 3 small alternate leaves lower in the stem. 

 From the centre of the leaves 1-4 slender pedicels arise, each 

 terminated by a single flower, white or very pale pink with a 

 yellowish ring. Corolla rotate. Calyx-segments narrow. Stamens 

 with slender filaments. 



Peat bogs and damp woods ; very local. May to July. 



Distribution. -Very rare in Switzerland (Bernina, Poschiavo, 

 Wildhaus, Zumdorf, etc.), Savoie (Albertville), Ardennes, Corsica, 

 Southern Tyrol, Carniola, Central and Northern Europe ; especially 

 common in Norway and the Scotch Highlands ; Northern Asia and 

 Arctic America. British. 



SAMOLUS L. 

 Samolus Valerandi L. Brookweed. 



This plant, which grows almost at sea-level in England, is not 

 infrequently seen in damp places in the lower Alps and Pyrenees, 

 but it is rare in Switzerland. Leaves obovate, entire, dark green, 

 glabrous like the whole plant, usually alternate. Stems 6-12 inches 

 high. Flowers small, milk-white, in terminal racemes or corymbs. 

 Stamens 5. Seed-vessels a 5-valved capsule. 



Marshes, by ditches, and in the mountains on wet rocks, it 

 having been observed on damp rocks by the writer in both Alps 

 and Pyrenees at a considerable elevation. June to August. 



Distribution. Alps, Jura, Vosges, Pyrenees ; most of Europe, 

 and indeed in most temperate regions of the world. British. 



ASCLEPIADACE^ 



Flowers regular. Calyx 5-toothed. Corolla 5-lobed. Stamens 

 usually 5 united round the stigma into a column. Ovary 2-celled, 

 the carpels connate above. Seed-vessel of two follicles, with 

 numerous seeds clothed with silky hairs. Leaves opposite, entire. 



A large family, chiefly of tropical and sub- tropical trees and 

 shrubs with milky juice. There are very few European species. 



VINCETOXICUM Moench. 



Corolla rotate, 5-lobed, with 5 internal scales. Stigma apiculate. 

 About 80 species in the tropical or sub-tropical regions of both 

 Old and New World. 



Vincetoxicum officinale Moench. (Cynanchum Vincetoxicum R.Br.). 

 (Plate X.) 



A rather shrubby or straggling plant from I to nearly 3 feet high, 



