. The ecological relations of roots . s of the tapwere very sparsely branched, the few rootlets being of the same character asthose nearer the surface. From the description and figure it will be seen thatwhile this species has a strong tap-root, it also has a highly developed absorb-ing and binding system characteristic of the general group of sandhill plants. Tradescantia virginiana.—This spiderwort is rather common in the sand-hills. The plants were examined on a partially captured blowout. They hada rather fleshy root system. As many as 18 of these fleshy roots, varying from1 to 2 nam. in d
. The ecological relations of roots . s of the tapwere very sparsely branched, the few rootlets being of the same character asthose nearer the surface. From the description and figure it will be seen thatwhile this species has a strong tap-root, it also has a highly developed absorb-ing and binding system characteristic of the general group of sandhill plants. Tradescantia virginiana.—This spiderwort is rather common in the sand-hills. The plants were examined on a partially captured blowout. They hada rather fleshy root system. As many as 18 of these fleshy roots, varying from1 to 2 nam. in diameter, were foimd arising from the base of a single stem (); some passed down almost vertically to a maximum depth of 19 inches;others started down more or less vertically, then with a gradual curve out-ward ended from 6 to 8 inches from the vertical; others passed more or lessobHquely downward from the stem. The greater part of these fleshy roots,however, formed a surface absorbing system which spread out in all directions. 74 THE ECOLOGICAL RELATIONS OF ROOTS. from the base of the stem, running more or less parallel with the soil smfaceat a depth of 2 to 5 inches and to a maximmn distance of 30 inches. All the roots, whether superficial or deeper, were practically free frombranches for a distance of 4 to 6 inches. From that point on they began tobranch, the branches increasing in number toward the tips. These branchesvaried from a few millimeters to 3 or 4 cm. in length, and at intervals on these
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Keywords: ., bookcentury1900, bookdecade1910, bookidecologicalre, bookyear1919
