. Plant studies; an elementary botany. Botany. 90 PLANT STUDIES by numerous thread-like processes spreading in every direc- tion than by flat, expanded processes. It should also be noted that as soil roots are suljterra- neaii they are used often for the storage of food, as in the case of many sul)teri-anean stems. Certain prominent root types may he noted as follows : (;4. Soil roots.—These roots push into the ground witli great energy, . / \ \( '^^'^ their alv s 0 r I3 i n g s u r - faces are en- tirely covered. Only the yoniig- est parts of a root system absorb actively, the older parts tra
. Plant studies; an elementary botany. Botany. 90 PLANT STUDIES by numerous thread-like processes spreading in every direc- tion than by flat, expanded processes. It should also be noted that as soil roots are suljterra- neaii they are used often for the storage of food, as in the case of many sul)teri-anean stems. Certain prominent root types may he noted as follows : (;4. Soil roots.—These roots push into the ground witli great energy, . / \ \( '^^'^ their alv s 0 r I3 i n g s u r - faces are en- tirely covered. Only the yoniig- est parts of a root system absorb actively, the older parts transporting the absorl)ed material to the stem, and liel})- iug to gri]) the soil. The soil root is the most common root t y p e , li e i n g used 1)y tlie great majority of seed plants and fern jjlants, and amojig the moss plants the very simple root-like pro- cesses are mostly soil-relat(Ml. To such roots the water of tlie soil ])resents itself cither a^ free wafer—that is, water that can be drained away—or as films of wafer adhering to each soil particle, often called ivater of ndJiesimi. To come in contact with this water, imt tmly does tlu' roof system usually branch profusely in every direction, but the youngest branches develop abundant absorbing hairs, or roat hairs (see Fig. 84), which crowd in among the soil particles and. —^3—s-^JJLa^ FiG. SI. Knot tips of corn, Hhowiiig root hairs, their position ill refcrf'iicu to the growing tip, and the effect of tlic surrounding mediiun upon tlieir development : 1, in soil ; 2, in air ; :i, in 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 Coulter, John Merle, 1851-1928. New York, D. Appleton and Company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1900
