. A Manual of botany : being an introduction to the study of the structure, physiology, and classification of plants . Botany. VERNATION OR PR^FOLIATION. Ill in Ferns (fig. 222 g), and called cirmiate (circino, I turn round); or folded laterally, conduplicate, as in Oak (fig. 222 b); or it has several folds like a fan, plicate or plaited, as in Vine and Sycamore (figs. 221 /,, 222 c), and in leaves witli radiating' vernation, where the ribs mark the foldings ; or it is rolled upon itself, convolute or supervolute, as in Banana and Apricot (fig. 222 d) ; or its edges are rolled inwards, involut
. A Manual of botany : being an introduction to the study of the structure, physiology, and classification of plants . Botany. VERNATION OR PR^FOLIATION. Ill in Ferns (fig. 222 g), and called cirmiate (circino, I turn round); or folded laterally, conduplicate, as in Oak (fig. 222 b); or it has several folds like a fan, plicate or plaited, as in Vine and Sycamore (figs. 221 /,, 222 c), and in leaves witli radiating' vernation, where the ribs mark the foldings ; or it is rolled upon itself, convolute or supervolute, as in Banana and Apricot (fig. 222 d) ; or its edges are rolled inwards, involute, as in Violet (fig. 222 e) ; or outwards, revolute, as in Eose- maiy (fig. 222 /). The difi'erent divisions of a cut leaf may be folded or rolled up separately, as in Ferns, while the entire leaf may have either the same or a different kind of vernation. Other kinds of vernation receive their names from the arrange- ment of the leaves in the bud, taken as a whole. Leaves in the bud. Pig. 222. are opposite, alternate, or verticillate; and thus different kinds of vernation are produced. Sometimes they are nearly in a circle at the same level, remaining flat, or only slightly convex externally, and placed so as to touch each other by their edges, thus giving rise to valvule vernation (fig. 222, h). At other times they are at different levels, and are applied over each other, so as to be imbricated, as in Lilac, and in the outer scales of Sycamore (figs. 220, 221) ; and occasionally the margin of one leaf overlaps that of another, while it, in its turn, is overlapped by a third, so as to be twisted, spiral, or con- tortive (fig. 222 i). When leaves are applied to each other, face to face, without being folded or rolled together,.they are appressed. When the leaves are more completely folded they either touch at their Fig. 222. Diagrams to show the different Icinds of vematiou. o-gr, The folding of indi- vidual leaves ; a and g being vertical sections, bode and/being horizontal, a
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1875
