| 释义 |
bract|brækt|
Also bracte; and in L. form bractea, pl. bracteæ, also occas. bracteas.
[ad. L. bractea (formerly used unchanged) a thin plate or leaf of metal, gold-leaf; cf. Fr. bractée.]
1. Bot.
a. A small modified leaf, or scale, growing immediately below the calyx of a plant, or upon the peduncle of a flower.
1770Ellis in Phil. Trans. LX. 520 Under this flower-cup are four floral leaves, or bracteæ. 1794Martyn Rousseau's Bot. xiii. 149 A lateral leaf to each calyx, which Linnæus calls the..bracte. 1807J. E. Smith Phys. Bot. 22 The Lavenders..have coloured bracteas. 1835Lindley Introd. Bot. (1848) I. 309 There are..no exact limits between bracts and common leaves. 1884J. E. Taylor Sagac. & Mor. Plants 103 In the Yew..some bracts become aborted.
b. attrib., as in bract-sheath; also deriv. ˈbractless a. bract-like adjs.
1847Craig, Bractless, without bracts. 1847W. E. Steele Field Bot. 167 S[piranthes] autumnalis, root-leaves oblong, those of stem bract-like. 1870Hooker Stud. Flora 415 Carex præcox..bract-sheaths short. 1911F. O. Bower Plant-Life on Land iv. 64 The calyx sprang from bract-like leaves.
2. Zool. A similar appendage found in some of the Hydrozoa.
1878Bell Gegenbauer's Comp. Anat. 97 Nutritive, generative, and tentacular individuals are generally placed together in groups, in such a way that there is one bract to a group. |