STRUCTURE OF PLANTS. 
J 
H 
Pgi Gllllitlls aie those that live and bloom year after year, except under extraordinary 
' icissitudes, many ol them blooming the first summer if sown early in the spring. Such 
plants can be propagated by a division ot the roots and cuttings as well as by seeds. Some 
of these cannot he sui passed for utility and beauty, and are best for permanent beds where 
ciicumstances will not permit the steady attention demanded by other classes of flowers. 
I 
ST JEMS. 
'&&L 
35 
^ '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. 
^ It usually seeks the light, appearing above the ground, and is sub- 
{ divided as follows: Simple, when found without branches (8), as 
in the Parnassia; compound, when branched, as in the Chickweed 
(9 )> forked, when parted into two equal or nearly equal branches, as 
Bouvardia (10); erect, when growing upright, ascending, when 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 (11); prostrate, 
or procumbent, when it lies flat along the ground, as in the Petunia; creeping, 
01 repent, when it runs along the ground and sends out roots from its joints — 
sometimes a plant has an upright stem, and sends out creeping shoots from its base, as 
in the Strawberry (12); twining, or voluble, as in the Hop, when they rise by spirally 
coiling themselves around supports; climbing, or scandent, when they rise by clinging 
step by step to other objects, as in the Ivy. 
Stems aie classified according to certain peculiarities of size and duration, as follows: 
Herbaceous, when they die down to the ground every year, as in Mint or other herbs, 
whence the epithet; jfruticose, when living from year to year, and of considerable size, 
like Lilac or other shrubs; suffruticose, when fruticose or shrubby below, and herbaceous 
above, as the Horseshoe Geranium; suffrutescent, when the stem has an appearance of 
being modeiately shrubby, and is only a little woody, as the Pelargonium; arborescent, 
when appioaching to a tiec-like appearance, as the Oleander; and arboreous, when it is 
the trunk ot a tree properly so called, as the Magnolia. 
The stem is composed—beginning from the center—of the pith, the soft, spongy 
substance in the center of many plants, consisting of cellular tissue; the wood, or material 
immediately surrounding the pith; the liber, or inner bark, which is fibrous; the cortex, 
oi outei bark, which consists of cellular tissue only; and the epidermis, or skin — a thin, 
inembi aneous covering, with pores, that envelops all the rest. The stem, longitudinally 
consideied, 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, 
se\ ei al foims of underground stems, as the rhizoma, or rootstalk, a creeping stem grow¬ 
ing wholly or partly beneath the soil; the conn, which is a very short, fleshy rhizoma; 
the bulb, a shorter stem, usually underground, with excessively crowded and overlapping 
coats, and the bulblct, which is a small excresence that grows on the older and larger bulb. 
4°5 
*\V 
-777- 
L»- 
