. Elements of botany. Plants. ROOTS. 29 strength of the supplies of ready-made sap which it obtains from the host. 43. Forms of Roots. — The primary root is that which proceeds like a downward prolongation directly from the lower end of the caulicle. In many cases the mature root-system of the plant contains one main portion much larger than any of its branches. This is called a taproot, Fig. 16. Such a root, if much thickened and fleshy, would assume the form shown in the carrot, pars- nip, beet, turnip, salsify, or radish. Some plants produce multiple lynmarij roots, a cluster proceeding fro
. Elements of botany. Plants. ROOTS. 29 strength of the supplies of ready-made sap which it obtains from the host. 43. Forms of Roots. — The primary root is that which proceeds like a downward prolongation directly from the lower end of the caulicle. In many cases the mature root-system of the plant contains one main portion much larger than any of its branches. This is called a taproot, Fig. 16. Such a root, if much thickened and fleshy, would assume the form shown in the carrot, pars- nip, beet, turnip, salsify, or radish. Some plants produce multiple lynmarij roots, a cluster proceeding from the lower end of the caulicle at the Fig. 15. — Dodder (a European speeiti tic ou the Willow. Parasi- Roots of grasses, etc., are thread-like,and known as fibrous roots, Fig. 17. If such roots become thick- ened like those of the dahlia. Fig. 18, they are known as fascicled roots. These often closely re- semble tubers, but they may be distinguished from them The plant is seen encircling a willow twig, into Mliich it sentls roots from the warty inner surface of its coils. b, scale-like leaves ; Bl, tlower-cluster. At the left is shown the manner in which the parasite Cus encircles the host-plant W. The parasitic roots or haustoria H penetrate into the parenchyma of the bark and into the fibro-vascular bundles, attaching them- selves to the various kinds of tissue, r, c, s, which they find in these. At the right are seedling dodder plants, the longest one growing at the tip from nourish- ment which it procures fi"om the dying end next the root. by their mode of. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bergen, Joseph Y. (Joseph Young), 1851-1917; Bergen, Joseph Y. (Joseph Young), 1851-1917. Bergen's Botany: key and flora, Pacific coast ed. Boston : Ginn
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectplants, bookyear1896
