. The anatomy of woody plants. Botany -- Anatomy. THE STEM 187 advantageous. In Fig. 140^ is shown the stem of a woody Poten- tilla (Potenlilla palustris). There are five broad segments of the stem, and alternating with these are five narrower ones. The more exiguous segments are related to the leaf traces and are charac- terized, as are the similar regions of the woody axes of Casuarina and Alnus repre- sented in earlier illustrations in this work, by the con- spicuous absence of the vessels pres- ent in the remain- ing and broader sectors. Although in the outer region the sectors under discu
. The anatomy of woody plants. Botany -- Anatomy. THE STEM 187 advantageous. In Fig. 140^ is shown the stem of a woody Poten- tilla (Potenlilla palustris). There are five broad segments of the stem, and alternating with these are five narrower ones. The more exiguous segments are related to the leaf traces and are charac- terized, as are the similar regions of the woody axes of Casuarina and Alnus repre- sented in earlier illustrations in this work, by the con- spicuous absence of the vessels pres- ent in the remain- ing and broader sectors. Although in the outer region the sectors under discussion show a complete absence of vascular struc- tures, in the region near the pith a few elements of this nature are present. These belong to the leaf trace proper, which lies on the inner sur- face of the narrower segments of the stem. Not only is the leaf trace segment narrower and distinguished by the absence of vascular structures, except in the actual trace itself, but it is depressed below the surface of the adjoining broader sectors. In b these features are indicated on a larger scale, so that the .conditions described become the more obvious. It will be noted under the more favor- able conditions of greater enlargement that the cluster of vessels lying on the inside of the narrow segment and near the pith is flanked on either hand by a region free from vessels. In c is shown the organization of the perennial region of the stem in another. A FIG. 140.—Diagrammatic representation of stems of species of Potcntilla. Explanation in the 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 Jeffrey, Edward C. (Edward Charles), b. 1866. Chicago, Ill. , The University of Chicago Press
Size: 1464px × 1708px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookpublisherchicagoilltheuniversityo, booksubjectbotanyanatomy
