. Botany for high schools and colleges. Botany. 444 BOTANT. bundles are more numerous. In such a stem it is evident that there can be no considerable increase in thickness after it is once formed, and we consequently find that palms take a longtime for the formation of a broad bud or growing point {punctum vegetationis), and afterward push up a cylin- drical stem in which little change subsequently takes place. In the Dragon trees {Draccena, sp.) and some other Monoco- tyledons, there is a thick layer of paren- chymatous cortex be- tween the column of fibro-Tascular bundles and the epidermis (
. Botany for high schools and colleges. Botany. 444 BOTANT. bundles are more numerous. In such a stem it is evident that there can be no considerable increase in thickness after it is once formed, and we consequently find that palms take a longtime for the formation of a broad bud or growing point {punctum vegetationis), and afterward push up a cylin- drical stem in which little change subsequently takes place. In the Dragon trees {Draccena, sp.) and some other Monoco- tyledons, there is a thick layer of paren- chymatous cortex be- tween the column of fibro-Tascular bundles and the epidermis (Fig. 322, r), and in the deeper layers of this a persistent meri- stem tissue is found (Fig. 322, x). In this meristem there are formed fibro-vascular bundles,which lie par- allel to those already formed, and in this way the stem slowly increases in thickness. 545.—In those Di- cotyledons whose Fig. 323.—Crosp-section of ptem of Dracama, €, , epidermis; k. cork; r, cortex; b, ii fibre vascular StemS increase in bundle bending out to a leaf ; m, parei cliynia of tlie .i • i .i i fundamental system; g, g, flbro-vasciilar bundles; thlCKneSS there always flj, meristem zone of the fundamental system in j^,,;ic! onnn a Iottq^. which new bundles and tissues are forming.—After ueveiopb SOOn d layer ^^'^^^- of meristem tissue, which connects the cambium layer of one fibro-Tascular bundle with that of the other (Fig. 323). This is made easier from the fact that in most (but not all) Dicotyle- dons the bundles lie at nearly the same depth beneath the epidermis on all sides of the stem, thus forming a cylinder, or in cross-section, a ring, as in Fig. 323. Both the fascicu-. 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 Bessey, Charles E. (Charles Edwin), 1845-1915. New York : H. Holt
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1885
