. The elements of botany for beginners and for schools. Plants. SECTION 5.] ROOTS. 33 Section V. HOOTS. 65. It is a property of stems to produce roots. Stems do not spring from roots in ordinary cases, as is generally thought, but roots from Btems. When perennial herbs arise from the ground, as they do at spring-time, they rise from subterranean steins. 66. The Primary Root is a downward growth from the root-end of the caulicle, that is, of the initial stem of the embryo (Fig. 5-7, 81). If it goes on to grow it makes a main or tap-root, as in Fig. 37, etc. Some plants keep this main root throu
. The elements of botany for beginners and for schools. Plants. SECTION 5.] ROOTS. 33 Section V. HOOTS. 65. It is a property of stems to produce roots. Stems do not spring from roots in ordinary cases, as is generally thought, but roots from Btems. When perennial herbs arise from the ground, as they do at spring-time, they rise from subterranean steins. 66. The Primary Root is a downward growth from the root-end of the caulicle, that is, of the initial stem of the embryo (Fig. 5-7, 81). If it goes on to grow it makes a main or tap-root, as in Fig. 37, etc. Some plants keep this main root throughout their whole life, and send off only small side branches ; as in the Carrot and Radish : and in various trees, like the Oak, it takes the lead of the side-branches for several years, unless accidentally injured, as a strong tap- root. But commonly the main root divides off very soon, aud is lost in the brandies. Multiple primary roots now ami then occur, as in the seedling of Pumpkin (Fig. "27), where a cluster is formed even at the first, from the root-end of the caulicle. G7. Secondary Roots are those which arise from other parts of the stem. Any part of the stem may produce them, but they most readily come from the As a general rule they naturally spring, or may be made to spring, from almost any young stem, when placed in favorable circumstances,—that is, when placed in the soil, or otherwise supplied with moisture and screened from the light. For the special tendency of the root is to avoid the light, seek moisture, and therefore to bury itself in the soil. Propagation by division, which is so common and so very important in cultivation, depends upon the proclivity of steins to strike root. Stems or branches which remain underground give out roots as freely as roots themselves give oil' branches. Siems which creep on the ground most commonly root at the joints; so will most branches when bent to the ground, as in propagation by layer- ing; and propagati
Size: 1375px × 1818px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectplants, bookyear1887
