| 释义 |
dicotyledon Bot.|ˌdaɪkɒtɪˈliːdən|
[f. mod. Bot.L. dīcotylēdones (plural), f. Gr. δι- twice + κοτυληδών cup-shaped hollow or cavity: see cotyledon.
(The term Dicotyledones was employed by Ray, but its practical introduction into botanical classification dates from Jussieu 1779.)]
A flowering plant having two cotyledons or seed-lobes: the Dicotyledons (in Bot.Lat. Dicotyledones) constitute one of the great classes of flowering plants, characterized by an exogenous mode of growth (hence also called exogens), and usually by having the parts of the flower in fives or fours, and the veins of the leaves reticulated.
[1703Ray Methodus Plant. (ed. 2) 1 Floriferas dividemus in Dicotyledones, quarum semina sata binis foliis anomalis, Seminalibus dictis, quæ Cotyledonum usum præstant, è terra exeunt.] 1727Bailey vol. II, Dicotyledon (with Botantists), a Term used of Plants, which spring with two Seed Leaves opposite to each other, as the generality of Plants have. 1830Lindley Nat. Syst. Bot. Introd. 15 Two great divisions..Monocotyledons and Dicotyledons. 1839Penny Cycl. XIII. 157 In his ‘Genera Plantarum’ Jussieu divided the vegetable kingdom into classes, subclasses, orders, and genera..hence his classes Acotyledons, Monocotyledons, and Dicotyledons. 1875Bennett & Dyer Sachs' Bot. ii. v. 564 In the great majority of Dicotyledons the parts of the flower are arranged in whorls..the whorls are usually pentamerous, less often tetramerous. |