| 释义 |
exogen Bot.|ˈɛksəʊdʒɪn|
[in Fr. exogène (De Candolle 1813), mod.L. exōgena, -us (imitating L. indigena, -us) adj., growing on the outside, used in fem. as n., f. Gr. ἔξω (see exo-) + γενής born, produced.]
A plant whose stem grows by deposit on its outside; opposed to endogen.
The class of Exogens is identical with that of the Dicotyledons, one of the two main divisions of phanerogamous plants. (But see: quot. 1889, and cf. Balfour in Encycl. Brit. IV. 99).
[1830Lindley Nat. Syst. Bot. 1 Exogenæ have a distinct deposition of pith, wood, and bark.] 1838Penny Cycl. X. 128/1 Exogens have an embryo so robust as to be able to spring at once into existence. 1873Dawson Earth & Man. vi. 121 Those higher plants which start in life with two seed⁓leaves, and have stems with distinct bark, wood, and pith—the Exogens. 1889Chambers' Cycl., Exogenous Plants, or Exogens, a term applied to dicotyledons by Lindley to express an erroneous view of the mode of stem-thickening from that of monocotyledons, and now wholly disused by botanists. |