exogen

American  

[eks-uh-juhn] / ˈɛks əˌdʒən /

noun

plural

exogens

1. Physiology. the fourth and final stage in the hair growth cycle, in which an individual hair is released from the follicle and shed before a new one grows. Compare anagen, catagen, and telogen.

2. Botany. a plant that grows by adding to the stem's outside layer, which consists of bark separated by a layer of wood from the inner layer of pith. Exogens are the same as dicotyledons. Contrasts with endogen.

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Other Word Forms

• exogenic adjective
• exogenous adjective
• exogenously adverb
• exogeny noun
• quasi-exogenous adjective

Example Sentences

Professor Huxley is credited with the assertion that the primrose is "a corollifloral dicotyledonous exogen, with a monopetalous corolla and a central placenta."

From English as She is Wrote Showing Curious Ways in which the English Language may be made to Convey Ideas or obscure them. by Anonymous

It is, according to Von Martius, the Cedrela Odorata, an exogen belonging to the same order as the mahogany tree.

From The Naturalist on the River Amazons by Bates, Henry Walter

The former sees a tree in all its glory, where the latter sees an exogen with a pair of cotyledons.

From The Unseen World and Other Essays by Fiske, John

Clumps of palms threw their fronds above the forest roof in some places, or a giant exogen raised a dome; but that was all.

From The Sea and the Jungle by Tomlinson, H. M. (Henry Major)

Smilax belongs to a transition class, partaking somewhat of the nature of endogen and of exogen.

From Scientific American Supplement, No. 623, December 10, 1887 by Various