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vascular bundle

(Encyclopedia)vascular bundle, in botany, a strand of conducting tissue extending lengthwise through the stems and roots of higher plants, including the ferns, fern allies, gymnosperms, and angiosperms. The vascula...

Hales, Stephen

(Encyclopedia)Hales, Stephen, 1677–1761, English physiologist and clergyman. From 1709 he was perpetual curate of Teddington. His experimental studies in animal and plant physiology contributed greatly to the pro...

auxin

(Encyclopedia)auxin ôkˈsĭn [key], plant hormone that regulates the amount, type, and direction of plant growth. Auxins include both naturally occurring substances and related synthetic compounds that have simila...

algebra

(Encyclopedia)algebra, branch of mathematics concerned with operations on sets of numbers or other elements that are often represented by symbols. Algebra is a generalization of arithmetic and gains much of its pow...

tapioca

(Encyclopedia)tapioca tăpēōˈkə [key], widely used starchy food, obtained from the fleshy root of the bitter cassava. Tapioca is sold in flake or flour form and as the pellet pearl tapioca. Tapioca flour is wid...

Gauck, Joachim

(Encyclopedia)Gauck, Joachim, 1940–, German political and human-rights activist, president of Germany (2012–17), b. Rostock. An anticommunist from his youth, Gauck was ordained a Lutheran minister and was pasto...

celery

(Encyclopedia)celery, biennial plant (Apium graveolens) of the family Umbelliferae (parsley family), of wide distribution in the wild state throughout the north temperate Old World and much cultivated also in Ameri...

rhizome

(Encyclopedia)rhizome rīˈzōm [key] or rootstock, fleshy, creeping underground stem by means of which certain plants propagate themselves. Buds that form at the joints produce new shoots. Thus if a rhizome is cut...

nitrogen cycle

(Encyclopedia)CE5 Nitrogen cycle nitrogen cycle, the continuous flow of nitrogen through the biosphere by the processes of nitrogen fixation, ammonification (decay), nitrification, and denitrification. Nitrogen...

parsley

(Encyclopedia)parsley, Mediterranean aromatic herb (Petroselinum crispum or Apium petroselinum) of the carrot family, cultivated since the days of the Romans for its foliage, used in cookery as a seasoning and garn...