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6th. Frond. (Fig. 23.) The term, Frond, belongs entirely to Cryptogamous plants. This term however is applied to the leaf rather than the stem; in this sketch of the fern the leafy part is the frond; this bears the flower and fruit. Linnæus considered the leaves of palm trees as fronds; we shall hereafter observe upon the different internal structure of their stems from those of the oak and other
plants which are termed cauline, because their stem is a caulis. Plants with fronds and stipes are sometimes called by the general name of stiped-plants; they are monocotyledonous. The stem of the fern (Fig. 23, a), is called a stipe. By observations of geologists it is ascertained that stiped plants were created before cauline ones; since petrifactions of the former are found in the lower formations of the earth, while no remains of cauline plants are ever found in them. Here is the sketch of a fern; its stem a, is called a frond.
7th. Stipe (Fig. 24), is the stem or leafless part of a frond, or the stalk of a fungus or mushroom. c The term is also applied to the slender thread, which in many of the compound flowers, elevates a the hairy crown, with which the seeds are furnished, and connects it with the seed. Thus, in the b seeds of the Dandelion, which is here represented, the column (Fig. 24, a), standing on the seed (b), and elevating the down (c), is the stipe.
Here is a mushroom with the cap (Fig. 25, d), elevated on its stipe (e).
Having considered the different kinds s of stems, according to the division which most botanical writers have made, we will now notice some general circumstances relating to them, without reference to any one of these classes of stalks in particular.
The coherence or hardness of stems has given rise to the following distinctions:
Frond-Which part of the fern is its frond ?-Which the stipe ?-Difference between stiped and cauline plants-Which first formed?-Different applications of the term stipe-Stipe of a dandelion seed--Of a fungus.
Herbaceous, having a tender substance, which usually dies every year; in some cases when the root lives more than one year, the stem is annual; as in the tulip; Woody, as in the oak; Solid, like the box; Pithy, as the elder; Hollow, as in the onion; Corky, as in the cork; or Pulpy, as in the cactus or prickly pear.
The stem with respect to its direction, or mode of growth, is
Perpendicular, or erect, forming a right angle with the ground, as the Pink;
Oblique, when it is neither perpendicular nor horizontal;
Reclining, curved towards the ground as the Blackberry;
Radical, clinging to some other body for support, by means of fibres which do not imbibe nourishment; as the common Creeper;
Climbing, either with spiral tendrils for its support, as the Vine, or by adhesive fibres;
Twining, winding in a spiral manner around other plants, as the Hop; Trailing, a creeping stem destitute of flowers, thrown out from the root and giving rise to another plant where it takes root, as the Strawberry.
Stems as to shape, are,
Terete or cylindrical, long and round; as in the rose and lilac, and in most of the woody and herbaceous plants;
Compressed, more or less flattened on the sides;
Anceps, two edged;
Triangular, three edged;
Quadrangular, square, or four sided;
Pentagonous, five sided. If the number of angles is either variable, or more than five, the stem is said to be angulosus, or angled.
The surface of the stem may be,
Glabrous, smooth, destitute of hairs or glands;
Polished, the surface equal and smooth:
Pubescent, covered with hair, or glands resembling hairs;
Villose, shaggy, covered with long soft hairs;
Pilose, hairs long and distinct;
Tomentose, hairs short and closely matted together, like cotton or down;
Hispid, bristly, hairs stiff;
Scaly, covered with membranous scales;
Imbricated, stem concealed by leaves, which sit close like shingles on the roof
of a house;
Mealy, (glaucus,) of a sea-green mealiness, which easily rubs off;
Striated, marked with parallel longitudinal lines.
The stem is either simple, or divided into branches. branches are parts of the plant which proceed immediately from the trunk; the divisions of the branches are called branchlets; a diminutive appellation, which means a little branch. These parts resemble, in their formation, the trunk or stem, which furnishes them; the branch may be considered as a tree, implanted upon another tree of the same species.
Branches sometimes grow without any apparent order in
Stems with respect to hardness-Direction-Shape- Surface-divisions Disposition of branches.
their arrangement; sometimes they are opposite; sometimes alternate; and sometimes, as in the pine, they form a series of rings around the trunk. Some branches are erect as in the poplar, others pendant as in the willow, and some, as in the oak, form nearly a right angle with the trunk.
These various circumstances constitute distinctive characters in plants, a knowledge of which is very necessary to the painter. Of all our forest trees, perhaps none, in the disposition of its branches, presents a more beautiful and graceful aspect than the elm.
The branches of trees, as they grow older, usually form a more open angle with the trunk than at first. We often see branches form a very acute angle, but as the tree advances in age, the angles enlarge more and more, until the branch becomes pendant.
Some stems are remarkable for bearing bulbs in the axils of their leaves.. These bulbs like the bulbous root, contain within them the germ of a new plant. The LILIUM BULBIFERUM, or bulbbearing lily is of this description, (Fig. 26.)
A remarkable phenomenon is described by travellers, as being exhibited by the stems of the Banyan tree of India, Ficus Indicus; their stems throw out fibres, which descend and take root in the earth. In process of time these stems become large trees, and thus from one primitive root, is formed a little forest. This tree is called by various names; as the Indian-God-tree, the arched-Fig-tree, &c,
The Hindoos plant it near their temples, and in many cases the tree itself serves them for a temple. Milton speaks of this tree as the one from which Adam and Eve obtained leaves to form themselves garments; he says it was not the fig-tree renowned for fruit, but
"Such as at this day to Indians known
Branching so broad and long, that in the ground
High over-arched, and echoing walks between."
Knowledge necessary to the painter-Branches alter in their disposition as they grow older-Bulb, bearing stems-Rooting stems.
You have here a description of this wonderful tree, which is said to have given shelter to an army of seventy thousand men. Fig. 27.
All the varieties of stems which we have now considered may be included under two divisions; 1st. such as grow externally, having their wood arranged in concentric layers, the oldest being in the centre of the trunk and the newest forming the outer layer. This kind of stem may be seen in the oak and other forest trees in our climate, and also in most of our common herbaceous plants; these spring from seeds with two cotyledons, and are called dicotyledons.
2d. Stems which grow internally, as palms and grasses, their wood instead of circling around the first formed substance, is pushed outwards by the developement of new fibres in the centre of the stem; this kind of stem belongs to plants whose seeds have but one cotyledon, and which are therefore called monocotyledons.*
Most leaves and flowers proceed from scaly coverings called buds. The scales envelope each other closely; the exterior
*These two kinds of stem have by some French botanists been called exogenous and endogenous; these words are derived from the Greek; the first signifying to grow externally, the second to grow internally.
ones being dry and hard, the interior, moist and covered with down; they are also furnished with a kind of resin or balsam, which prevents the embryo from being injured by too, much moisture: buds have been known to lie for years in water without injury to the infant plant or branch within.
The sap is the great fountain of vegetable life, by its agency new buds are yearly formed to replace the leaves and flowers destroyed by the severity of winter. Branches also originate from buds. Linnæus supposed that buds spring from the pith, this being found necessary to their formation and growth.
The bud is usually a cone-like protuberance formed by the swelling of the germ; and as for this purpose the agency of an additional quantity of sap is needed, we see the bud appearing at the axils of leaves or the extremities of branches and stems where there is an accumulation of this fluid.
If you plant a slip of Geranium, you will observe that it either sprouts from the axil of a leaf, or from knots in the stem which answer the same purpose as the leaf, by slightly interrupting the circulation of the juices, and thus affording an accumulation of sap necessary for the production of a new shoot.
Some botanists distinguish the bud as follows: that point in the plant which gives rise to the bud is called the eye; when this begins to swell and become apparent, it is called the button; and when it begins to unfold, the bud.*
Herbs and shrubs have buds, but these usually grow and unfold themselves in the same season, and are destitute of scales; while the buds of trees are not perfected in less than two seasons, and in some cases they require years for their full developement. You have, no doubt, observed in the spring, the rapid growth of the leaves and branches of trees; and perhaps, have also noticed, that as summer advances, the progress of vegetation seems almost to cease, and that new leaves and branches do not come forth as before; but you may not have known, that instead of resting in her operations, nature is now busy in providing for the next year; that she is turning the vital energies of the plants to the formation of buds. Those little embryo plants so nicely wrapped up in downy scales as to be able to bear the coldness of winter, in the ensuing spring will come forth from their snug retreats, and taking the places
* These terms in French are l'œil the eye, bouton the button, and bourgeons the bud.
Buds supposed to originate from the pith-Sap needed for its formationThe eye, button and bud-Herbs and shrubs destitute of scaly buds-Period in which the formation of buds commences.