. Carnegie Institution of Washington publication. 94 THE ECOLOGICAL RELATIONS OF ROOTS. effective absorbing system, which ramifies widely and fills the soil from a depth of from 4 to 36 inches. The whole root system is characteristic of the half-gravel-slide root habit. Besseya plantaginea.—This plant frequently grows in clusters of 3 or more, the individuals of which are connected by short rhizomes about 5 mm. or less in diameter and 2 or 3 inches long. The base of the plant and these rhizomes are densely covered with fleshy roots about 2 mm. in diameter. As many as 30 to 40 of these roots oc
. Carnegie Institution of Washington publication. 94 THE ECOLOGICAL RELATIONS OF ROOTS. effective absorbing system, which ramifies widely and fills the soil from a depth of from 4 to 36 inches. The whole root system is characteristic of the half-gravel-slide root habit. Besseya plantaginea.—This plant frequently grows in clusters of 3 or more, the individuals of which are connected by short rhizomes about 5 mm. or less in diameter and 2 or 3 inches long. The base of the plant and these rhizomes are densely covered with fleshy roots about 2 mm. in diameter. As many as 30 to 40 of these roots occur on a single inch of the rhizome. Many of them pursue a vertically downward course and end at a maximum depth of from 25 to 30 inches (fig. 39). Others run out rather parallel with the surface of the soil and at a depth of 2 or more inches to a distance of over a foot, when they turn abruptly downward, reaching a depth of 16 or 18 inches. Still others. Fig. 39.—Besseya plantaginea, showing the widely spreading root system. fill in the angle between the horizontal and vertical roots, running off obliquely and then turning downward. Very few branches occur on the first 4 to 6 inches of the root. But beyond this point the roots (which are now a milli- meter or less in diameter) branch freely, sending off laterals to a distance of 5 or 6 inches, the last 12 to 18 inches being so well branched and rebranched as to form a fine absorbing network. Thus the soil within a radius of at least a foot from the plant and at a depth of from 20 to 30 inches (except the sur- face 2 inches) is rather completely filled with absorbing rootlets of this fleshy perennial. As its root system shows, Besseya is an excellent illustration of a. 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 Carnegie Institution of Washington. Wa
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