. The elements of botany for beginners and for schools. Botany. 68 LEAVES. [section Opposite (Tig. 182), wlien there is a pair to each node, the two leaves in this case being always on opposite sides of the stem ; Whorled or Verticillate (Fig. 1S3) when there are more tlian two leaves on a node, in which case they divide the circle equally between them, forming a Verticel or whorl. When there are three in the whorl, the leaves are one third of the circumference apart; wlieu four, one quarter, and so on. So tlie plan of opposite leaves, which is very common, is merely that of whorle
. The elements of botany for beginners and for schools. Botany. 68 LEAVES. [section Opposite (Tig. 182), wlien there is a pair to each node, the two leaves in this case being always on opposite sides of the stem ; Whorled or Verticillate (Fig. 1S3) when there are more tlian two leaves on a node, in which case they divide the circle equally between them, forming a Verticel or whorl. When there are three in the whorl, the leaves are one third of the circumference apart; wlieu four, one quarter, and so on. So tlie plan of opposite leaves, which is very common, is merely that of whorled leaves, with the fewest leaves to the whorl, namely, two. 183. In both modes and in all their modifica- tions, the arrangement is such as to distribute the leaves systematically and in a way to give them a good exposure to the light. 184. Ko two or more leaves ever grow from the same point. Tlie so- called Fe^nicled or Clustered leaves are the leaves of a braucli the nodes of which are very close, just as they are in the bud, so keeping the leaves in a cluster. This is evident in the Larch (Fig. 184), in which examination shows each cluster to be made up of nume- rous leaves crowded on a spur or short axis. In spring there are only such clusters; but in summer some of them lengthen into ordinary shoots with scat- tered alternate leaves. So, likewise, each cluster of two or three needle- shaped leaves in Titeh Pines (as in Fig. 185), or of five leaves iu White Pine, answers to a similar extremely short branch, springing from the axil of a thin and slender scale, which represents a leaf of the main shoot. For Pines produce two kinds of leaves, — 1. primary, the proper leaves of the shoots, not as foliage, but in the shape of delicate scales in spring, which soon fall away; and 2. secondary, the. fascicled leaves, from buds iu the axils oi the former, and these form the actual Please note that these images are extracted from scanned page images that may have been di
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