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.
One of the largest families, with over 3000 species represented in nearly every part of the world, except the Arctic regions. But we are unaware of a single species which is purely Alpine.
Herbs, in European species, with the inflorescence composed of many male and one female flower collected into a cluster, subtended by bracts and glands which are often yellow and crescent-shaped. Ovary 3-celled, with 3 bifid stigmas. Seed-capsule 3-lobed. Many have a milky juice.
About 650 species in the temperate and hot regions of both worlds, especially abundant in the Mediterranean district. None are truly Alpine.
Stems 8-12 inches high, erect, reddish at the base, rising from a stoloniferous root, and with numerous barren and flowering branches. Leaves linear, setaceous and almost imbricate, glabrous. Flowers yellow, often turning red in autumn, in a terminal umbel, with a whorl of linear leaves at its base. Bracts broadly ovate-triangular. Capsule 3 mm. long, trigonous, glabrous.
Gravelly and stony places from the plains to the Alps, sometimes seen as high as 9000 feet, and often very abundant in the lower Alps. May to September.
Almost all Europe. Introduced into Britain.
Sometimes Cuscuta, or Dodder, is parasitical upon this plant. In the Zinal valley in the hot summer of 1911 much of it was seen on this rather unusual "host".