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Clements, Frederic Edward

(Encyclopedia)Clements, Frederic Edward, 1874–1945, American plant ecologist and pioneer in the study of succession (see ecology), b. Lincoln, Nebr., grad. Univ. of Nebraska, 1894. From 1917 to 1941 he was in cha...

pruning

(Encyclopedia)pruning, the horticultural practice of cutting away an unwanted, unnecessary, or undesirable plant part, used most often on trees, shrubs, hedges, and woody vines. Man uses pruning to remove diseased ...

tropism

(Encyclopedia)tropism trōpˈĭzəm [key], involuntary response of an organism, or part of an organism, involving orientation toward (positive tropism) or away from (negative tropism) one or more external stimuli. ...

froghopper

(Encyclopedia)froghopper or spittlebug, small, hopping insect of the order Homoptera. The adult, under 1⁄2 in. (1.2 cm) long in most species, is triangular in shape and usually gray or dull green to brown. Most f...

rose of Jericho

(Encyclopedia)rose of Jericho, common name for two plants belonging to different families in the plant kingdom. One, an annual desert plant (Anastatica hierochuntica) of the family Cruciferae (or Brassicaceae; must...

growing season

(Encyclopedia)growing season, period during which plant growth takes place. In temperate climates the growing season is limited by seasonal changes in temperature and is defined as the period between the last killi...

Temirtau

(Encyclopedia)Temirtau or Temir-Tau both: tyĭmēr-touˈ [key], city (1989 pop. 212,382), NE Kazakhstan, on the Nura River. It is an industrial center, with a large steel plant. Temirtau is also the site of the Sam...

Barking and Dagenham

(Encyclopedia)Barking and Dagenham bärˌkĭng ən dăgˈnəm, bôˌ– [key], outer borough of Gre...

Engelmann, George

(Encyclopedia)Engelmann, George ĕngˈəlmən [key], 1809–84, American physician and botanist, b. Frankfurt-am-Main, Germany, educated at the universities of Heidelberg and Würzburg (M.D., 1831). Emigrating to A...

sap

(Encyclopedia)sap, fluid in plants consisting of water and dissolved substances. Cell sap refers to this fluid present in the large vacuole, or cell cavity, that occupies most of the central portion of mature plant...