Ortho tri chum (orthotrikum)

[NL. (Hedwig, 1801), so called in allusion to the hairs on the calyptra; ally erect stems covered with crowded leaves, and a generally immersed capsule with peristome of sixteen teeth and calyptra usually covered with straight hairs, from which latter peculiarity they are called bristle-mo es. There are nearly 40 North American species. orthotropal pal (ôr-thotro-pal), a. p-ous + [ p - ous + -al.] Orthotropous. orthotropic (ôr-tho-trop'ik), a. [ The primary shoot of the seedling [of ivy] is, like that of Tropæolum, at first orthotropic and radial. IMG:content-1884.png:[graphic] Vines , Physiology of Plants, p. 425. orthotropism (ôr-thot'rō-pizm), n. [ orthot rop- ous + -ism .] + -ism .] In bot . , vertical growth: term proposed by Sachs for the habit of those organs of plants which grow more or le nearly vertically, either upward or downward, as iris-leaves, the majority of physiologically radial organs, etc. Compare plagiotropism . Since the light is equally intense on all sides of the shoot, it exerts no directive influence. Orthotropism is then mainly due to negative geotropism. Encyc . Brit ., XIX. 61. orthotropous (ôr-thot'rō-pus), a. [ ὀρθός , straight, + τρέπειν , turn: see trope .] In bot ., growing vertically or straight: applied specifically to an ovule in which the chalaza is at the evident base, and the orifice at the opposite extremity, the whole ovule being straight and symmetrical. The ovules of the Polygon aceӕ , Urticaceæ, etc., are examples. Better atropal (which see). Also applied to an embryo in which the radicle is directed to the hilum or to the micropyle ing the ovule . close to the hilum, as in an an at Orthotropous Ovule. Flower of Juglans nigra, cut longitudinally and show ropousovule. In the latter sense the same as homotropous. [