JOINTED CULMS.

79

We have yet to attend to the meaning of geniculatus. There is a species of grass which is very common in moist meadows; in places overflowed in winter; and in shallow ponds, and ditches; which is named the floating foxtail-grass (Alopecurus geniculatus). If you examine the knots, you will find that, instead of being equally prominent all round, one side projects, so that the knot is bent into an angle.

Now, genu means the knee, and from it geniculatus is derived, which therefore means not only jointed, but also, that the joints are bent like a person's knee. The culm of the floating foxtail-grass is therefore correctly defined, not articulatus, nor nodosus, but geniculatus; which at once expresses that it is a knotted culm, and that at each knot it is bent into an angle.

The only farther observation I have to make, respecting the culm, is, that the knots are often coloured differently from the rest of the stem; and that the space between knot and knot is called the internode (internodium).

The next species of stem we shall attend to is

THE STIPES, OR STIPE,

which is derived from the Greek σTUTOS (stupos), a stake. It is proper to Palms, Ferns, and Fungi, and

is applied also to the little pillar which supports the down of some seeds. Thus in the seed of the dandelion, the column (a) standing on the seed (b), and elevating the star of down (c), is the stipe.

α

b

In Fungi it is easily understood.

There is the

cap of a mushroom (d), and the stem on which it stands is named the stipe.

Before noticing the stipe in Palms and Ferns, it may be proper to explain the meaning of the term frond. The word FRONS originally meant a branch covered with leaves, or a leafy bough; but its application in Botany is more limited. Examine a Fern, and you will observe that the green parts, which would commonly be considered as distinct leaves, are expansions of the stem or stipe; that there is no line of separation between them; and that the stem, leaf, and generally the fructification, are as one body. Like a garment without a seam, they are all in one piece. In the frond, according to Sir James E. Smith, "the stem, leaf, and fructification are united; or, in other words, the flowers and fruit are produced from the leaf itself, as in the Fern tribe." Now, I would with all

*

* Introduction, p. 102.

STIPE OF FERNS AND PALMS.

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due deference suggest the possibility of this passage leading the young botanist to pronounce the butcher's broom, and some other plants which bear their flowers and fruit on the leaves, to be fronds; and besides, some of the ferns bear their fructifications in spikes distinct from the leaf, as in the genera of Osmunda, and Ophioglossum. In the English Botany, this excellent author says, "the Linnæan term frons cannot without violence be used in the genus of Ophioglossum, as there is no necessary connection between the leaf and fructification, one species, if not more, having them on distinct stalks." I believe, however, that Linnæus never contemplated this circumstance as essential to the constitution of a frond. He confined the term to palms and ferns, and he illustrates his definition in the Philosophia Botanica, by a figure of a palm leaf, though no one knew better than he, that in the palms the leaf does not bear the fructification. In the definition alluded to, he says that the frond frequently bears the fructification, not that it necessarily does so.

*

The Stipe, then, is the base or footstalk of the frond; and though it may in many ferns be considered as a true stem, yet in the palms it is only secondary, and the lofty stem which bears the frondose top of these majestic vegetables to the clouds, is nothing more than a congeries of the bases of former fronds, and of those which are con* Vide Philosophia Botanica, p. 42,

stantly pushing out from the summit; so that, notwithstanding their great height, and their appellation of Palm-trees, they are very different in structure, and mode of growth, from trees, properly so called. An idea of their manner of growth may be acquired from an examination of the white or orange lily, whose stems, "though of only annual duration, are formed nearly on the same principle as that of a Palm, and are really congeries of leaves rising one above another, and united by their bases into an apparent stem.” *

The stipe, in most ferns, is covered with chaffy scales, and in many palms it is thorny.

SCAPUS; THE SCAPE, OR FLOWER-STEM.

Scapus means the upright stem of an herb, or the shaft of a pillar, and in Botany is used for that sort of stem which rises directly from the root, and elevates the flowers, but not the leaves. You would not, therefore, call the footstalk of a rose a scape, because the stem of the rose-tree is covered with

and the latter do not rise

leaves, as well as flowers; directly from the root. But you would apply the term immediately to the stalk of the cowslip, because it does rise directly from the root, and bears the flower, but not a single leaf. The hyacinth, the lily of the valley, the snowdrop, the daffodil, the daisy, the primrose, and many other common

* Smith's Introduction to Botany, p. 46.

SCAPE, OR FLOWER-STEM.

83

plants, present examples of the scape; and when, as in the cowslip, it divides into branchlets which support a number of flowers, these branchlets or divisions are named pedicels, or pedicles (pedicelli.)

The scape is scaly in coltsfoot; spiral in cyclamen; semicylindric in lily of the valley; twoedged (anceps) in snowdrop; and triquetrous in Allium triquetrum, triangular-stalked garlic. Sometimes it has a very majestic appearance, tapering, as in the white Strelitzia (Strelitzia alba) to a height of thirty feet without a leaf; and the great American Aloe (Agave Americana), which sends up a flowerstem sometimes even forty feet high, and loaded with many thousands of flowers.

A previous knowledge of the culm will prevent our confounding it with the scape, which in some cases might otherwise be done; for some culms, that, for example, of the marsh club-rush (Scirpus palustris), agree perfectly with the scape in rising directly from the root; and in bearing the fruit and flowers, but not the leaves. I may mention also, that in some species, as the crocus, the meadow-saffron, &c. the part on which the flower stands is not a real scape. It is the tube of the flower which is continued down under ground, in which situation the seed is perfected.

We have now considered the stalk, the culm, the stipe, the frond, and the scape. The petiole or leaf-stalk, and the peduncle or flower-stalk,