| 释义 |
tap-root, n.|ˈtæpruːt|
[f. tap n.1 + root.]
A straight root, of circular section, thick at the top, and tapering to a point, growing directly downwards from the stem and forming the centre from which subsidiary rootlets spring.
1601Holland Pliny xvi. xxxi. 477 The Fir and Larch have one tap root and no more; for upon that one maine maister-root they rest and are founded. 1733Tull Horse-Hoeing Husb. i. 1 The Tap-Root commonly runs down Single and Perpendicular, reaching sometimes many Fathoms below. 1815J. Smith Panorama Sc. & Art II. 597 Such plants have no tap-roots, but strike their fibres horizontally in the richest part of the soil. 1851Glenny Handbk. Fl.-Gard. 160 It has a tap-root like a carrot, but small.
fig.1825Coleridge Aids Refl. (1836) 349 Its fibres are to be traced to the tap-root of humanity. 1887Lowell Democr. 36 This sentiment, which is the very tap-root of civilization and progress.
attrib.1890Eng. Illustr. Mag. Christm. No. 158 That's a tap-root idea, Fraser.
Hence ˈtap-root v. intr., of a plant, to send down a tap-root (whence ˈtap-rooting ppl. a.); ˈtap-rooted a., having a tap-root.
1725Bradley's Fam. Dict. s.v. Ilex, These, like our English Oak, are tap-rooted, and therefore delight in deep Soil. 1769L. Edward in Hist. Linc. (1834) I. 20 The oak roots stand upon the sand, and tap-root into the clay. 1805R. W. Dickson Pract. Agric. I. 12 In loosening the ground for carrots, or other tap-rooted plants. 1897Willis Flower. Pl. I. 185 Tap-rooting plants..would not be able to cling to their supports in time to prevent falling off. |