| 释义 |
heterodromous, a.|hɛtəˈrɒdrəməs|
[f. mod.L. heterodrom-us, f. Gr. ἑτερο- hetero- + -δροµος running + -ous. In mod.F. hétérodrome.]
Running in different directions: opp. to homodromous. †a. Mech. Applied to levers of the first order, in which the power and the weight move in opposite directions (obs.). b. Bot. Turning in opposite directions on the main stem and on a branch, as the generating spiral of a phyllotaxis.
1710J. Harris Lex. Techn. (ed. 2) II. s.v., The Wheel, Windlass, Capstand, Crane, &c. are perpetual Heterodromous Leavers. [1727–51Chambers Cycl., Heterodromus Vectis, in mechanics, a lever wherein the fulcrum, or point of suspension, is between the weight and the power.] 1870Bentley Bot. (ed. 2) iii. §3. 140 The successive leaves form a spiral round the axis..In the majority of cases, the direction in both the stem and branches is the same, and it is then said to be homodromous; but instances..occur in which the direction is different, when it is called heterodromous. 1874R. Brown Man. Bot. 190.
So heteˈrodromy Bot., heterodromous condition.
1886Syd. Soc. Lex., Heterodromy, term applied..when the axial shoot of the stem coils from right to left, whilst that of the branch twists from left to right, or vice versâ. |