. The American botanist and florist: including lessons in the structure, life, and growth of plants; together with a simple analytical flora, descriptive of the native and cultivated plants growing in the Atlantic division of the American union. Botany; Botany. 92 STRUCTUBAL BOTANY. alate^ also. Such leaves are said to be clecurrent {decurro, run down). Ex., Mullein. 275. The amplexicaul petiole is dilated at the base into a margin which surrounds or clasps the stem, as in the Umbelli- fers. Frequently we find the stem-clasping margins largely- developed, constituting a sheath—with free edges
. The American botanist and florist: including lessons in the structure, life, and growth of plants; together with a simple analytical flora, descriptive of the native and cultivated plants growing in the Atlantic division of the American union. Botany; Botany. 92 STRUCTUBAL BOTANY. alate^ also. Such leaves are said to be clecurrent {decurro, run down). Ex., Mullein. 275. The amplexicaul petiole is dilated at the base into a margin which surrounds or clasps the stem, as in the Umbelli- fers. Frequently we find the stem-clasping margins largely- developed, constituting a sheath—with free edges in the Grasses, or closed into a tube in the Sedges. 276. The petiole is simple in the simple leaf, but compound or branched in the compound leaf, Avith as many branches {2Mtio- lules) as there are divisions of the lamina. A leaf is simple when its blade consists of a single piece, however cut, cleft, or divided; and co)77poi(nd when it consists of several distinct blades, sup- ported by as many branches of a compound petiole. 277. Stipules are certain leaf-like expansions, always in pairs, situated one on each side of the petiole near the base. They do not occur in every plant, but are pretty uniformly present in each species of the same natural order. In substance and color they usually resemble the leaf; sometimes they are colored like the stem, often they are membranous and colorless. In the Palmetto its substance is a coarse net-work resembling Rose leaf, , «uh ? ttipiile':. 302, Violet (V. compound stipuleb. leaf (;), and free 278, Stipules are often cidnate, or adherent to the petiole, as in the Rose ; more generally they are free, as itr the Pea and Pansy. In these cases and others they act the part of leaves; again they are very small and inconspicuous. 279. An Ochrea is a membranous sheath enclosing the stem from the node upward, as in the Knot-grass family (Polygo- naceie). It is formed of the tAvo stipules cohering by their two margi
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1870
