The elements of botany for The elements of botany for beginners and for schools elementsofbotany00grayuoft Year: [1887] 68 LEAVES. [section 7. Opposite (Fig. 182), wlien there is a pair to each uode, the two leaves in this case being always on opposite sides of the stem; Whorled or (Fig. 183) when there are more than two leaves on a node, in which case they divide the circle equally between them, forming a Verticel or whorl. When there are three leaves in the whorl, tlie leaves are one third of the circumference apart; wiien four, one quarter, and so on. So the plan of opposi
The elements of botany for The elements of botany for beginners and for schools elementsofbotany00grayuoft Year: [1887] 68 LEAVES. [section 7. Opposite (Fig. 182), wlien there is a pair to each uode, the two leaves in this case being always on opposite sides of the stem; Whorled or (Fig. 183) when there are more than two leaves on a node, in which case they divide the circle equally between them, forming a Verticel or whorl. When there are three leaves in the whorl, tlie leaves are one third of the circumference apart; wiien four, one quarter, and so on. So the plan of opposite leaves, which is very common, is merely that of wliorled leaves, with the fewest leaves to tlie whorl, namely, two. 183. In both modes and in all tlieir modifica- tions, the arrangement is such as to distribute the leaves systematically and in a way to give them a gocd exposure to the light. ISi. No two or more leaves ever grow from the same point. The so- called Fascicled or Clustered leaves are the leaves of a branch 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 Pitch Pines (as in Fig. 185), or of five leaves in 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. piiraary, 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, i\ie fascicled leaves, from buds in the axils of the former, and these form the actual foliasre.
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