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STRUCrCRE OF PLANTS. 



Perennials are those that live and bloom year after year, except under extraordinary 

 vicissitudes, many of them blooming the first summer if sown early in the spring. Such 

 plants can be propagated by a division of the roots and cuttings as well as by seeds. Some 

 of these cannot be surpassed for utility and beauty, and are best for permanent beds where 

 circumstances will not permit the steady attention demanded by other classes of flowers. 



sometune 

 in the St 



%VB, 



STEMS. 



EXT to the root is the stem, or that part of the plant which springs 

 »^^\ from the root, and serves to support the leaves, buds and flowers. 

 i^'S^^ It usually seeks the light, appearing above the ground, and is sub- 

 ■ ' divided as follows: Simple., wYitw found without branches (8), as 

 in the Parnassia; componiuU when branched, as in the Chickweed 

 icj); forked, when partetl into two equal or nearly equal branches, as 

 in the Bouvardia (lo); erect, when growing wp\\ght, ascenditig-^vchen rising 

 obliquely upward — when several stems grow from the same root, the central 

 one is often erect and the others ascending, as in the Violet (ii); prostrate, 

 ox procumbent, when it lies flat along the ground, as in the Petunia; creeping, 

 or rcpei/t, when it runs along the ground and sends out roots from its joints — 

 a plant has an upright stem, and sends out creeping shoots from its base, as 

 wherry (12); twini/tff, or voluble, as in the Hop, when they rise by spirally 

 coiling themselves around supports; climbing, or scandcnt, when they rise by clinging 

 step by step to other objects, as in the Ivy. 



Stems are classified according to certain peculiarities of size and duration, as follows: 

 Herbaceous, when thcv die down to the ground every year, as in Mint or other herbs, 

 whence the cpitlii.t ; fruticosc,\\\\c\\ living from year to year, and of considerable size, 

 like Lilac or other shrubs; suffruticosc, when fruticose or shrubby below, and herbaceous 

 above, as the Horseshoe Geranium; suffrutescent, when the stem has an appearance of 

 being moderately shrubby, and is only a little woody, as the Pelargonium ; arborescent, 

 when approaching to a tree-like appearance, as the Oleander; and arboreous, when it is 

 the trunk of a tree properly so called, as the Magnolia. 



The stem is composed — beginning from the center — of the pith, the sof't, spongy 

 substance in the center of many plants, consisting of cellular tissue; the wood, or material 

 immediately surrounding the pith; the //i5er, or inner bark, which is fibrous; Xhc cortex, 

 or outer bark, which consists of cellular tissue only; and the epidermis, or skin — a thin, 

 membraneous covering, with pores, that envelops all the rest. The stem, longitudinally 

 considered, comprises the nodes, or knots; and internodes, or parts between the knots. 



It has been already stated that the stem is usually above ground; there are, however, 

 several forms of underground stems, 'as the rhizoma, or rootstalk, a creeping stem grow- 

 ing wholly or partly beneath the soil; the corm, which is a very short, fleshy rhizoma; 

 the bulb, a shorter stem, usualh' underground, with excessively crowded and overlapping 

 coats; an«] the bulblcl, which is a small excresence that grows on the older and larger bulb. 



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