Columbia Encyclopedia

(Encyclopedia) cover crop, green temporary crop grown to prevent or reduce erosion and to improve the soil by building up its organic content. Green-manure crops, which are specifically grown for their organic conte...

(Encyclopedia) ferrous sulfate or iron (II) sulfate, chemical compound, FeSO4. It is known as the monohydrate, FeSO4·H2O; the tetrahydrate, FeSO4·4H2O; the pentahydrate, FeSO4·5H2O; and the heptahydrate, FeSO4·7...

(Encyclopedia) Herrera, Carmen, 1915–, Cuban-American abstract painter, b. Havana. After studying architecture at the Univ. of Havana (1938–39), she trained at the Art Students League, New York (1942–43), then...

(Encyclopedia) beryl bĕrˈĭl [key], mineral, a silicate of beryllium and aluminum, Be3Al2Si6O18, extremely hard, occurring in hexagonal crystals that may be of enormous size and are usually white, yellow, green, b...

(Encyclopedia) Yorke, Henry Vincent: see Green, Henry. ...

(Encyclopedia) Péguy, Charles shärl pāgēˈ [key], 1873–1914, French poet and writer. Of a poor, working family, he won scholarships and made a brilliant record as a student. He left the École normale supérie...

(Encyclopedia) parakeet or parrakeet, common name for a widespread group of small parrots, native to the Indo-Malayan region and popular as cage birds. Parakeets have long, pointed tails, unlike the chunky lovebirds...

(Encyclopedia) liverwort, any plant of the class Marchantiopsida. Mosses and liverworts together comprise the division Bryophyta, primitive green land plants (see moss; plant); some of the earliest land plants resem...

(Encyclopedia) Cushing, Frank Hamilton, 1857–1900, American ethnologist, b. North East, Pa. He published his first scientific paper at the age of 17, and at 18 joined the American ethnology bureau at the Smithsoni...

(Encyclopedia) trogon trōˈgŏn [key], family of tropical jungle birds related to the roadrunners and including the quetzal. Trogons are sedentary arboreal birds, 10 to 14 in. (25.4–35.6 cm) long, with short roun...