Part 18

The Sundews, of which we have three native species, must be sought out, for they seldom obtrude themselves on the attention of those whose eyes have not been trained to see them. They must be looked for in peat bogs, and in hollows on sandy heaths, where they grow in crowds. The leaves of D. rotundifolia arise from a slender rootstock, and lie on the ground in the form of a rosette, from the centre of which the tall slender flower-stalks appear in July and August. Each leaf bears near the upper margins several rows of long crimson glands, terminating in rounded heads, and reminding one of a sea-anemone’s tentacles; indeed, they serve a similar purpose. These glands secrete a clear sticky fluid, which serves to detain small insects that crawl over the leaf. Their efforts to free themselves irritate the glands, which all bend over to the insect; at the same time the margins of the leaf-blade begin to become incurved, and the insect is effectually secured in the hollow, ultimately being digested and the soft parts assimilated by the plant. Readers desiring to learn more of these curious habits of the plant are advised to grow it in a saucer of peat, and to read Mr. Darwin’s celebrated work on “Insectivorous Plants.”

The leaf in this species, as its name signifies, has a round blade, and this is attached to a long hairy leaf-stalk. In the Narrow-leaved Sundew (D. intermedia) the blade is spoon-shaped, and merges insensibly into the smooth leaf-stalk. In the third species, or Long-leaved Sundew (D. anglica) the entire leaf is similar to that of intermedia, but twice the length. In neither of the long-leaved species are the leaves laid flat as in rotundifolia; those of intermedia are erect, whilst those of anglica are borne half-erect. D. anglica is rare in the South of England; the others are well distributed. The name is derived from the Greek, Drosera, dewy, in allusion to the bedewed appearance of the leaves.

=Barberry= (Berberis vulgaris).

The Common Barberry is a spiny shrub, growing in hedge and copse, and brightening the spot from April to June with its strings of yellow flowers, and later in the year with its oblong red berries. Its shoots attain a height of from six to eight feet, and are clothed in a whitish bark, the wood being yellow. The flowers include eight or nine sepals and six petals: the outer sepals are very small and liable to be overlooked. The petals are in two series, and at the base of each petal are two honey-secreting glands, which induce the visits of honey-loving insects. There are six stamens, which ordinarily lie along the centre of the petals, their bases highly irritable. In an open flower like this any insect can get at the honey, but it is not easy to do so without touching the base of one of the stamens; on this being done the stamen springs forward, and the anthers strike the insect, dusting it with pollen, and in some cases driving it away. This mechanism may be tested by touching the base of a stamen with the point of a pin.

The Barberry is very liable to the attacks of a minute fungus, a stage in the development of wheat-rust (Uredo graminis). The name Berberis is the Arabic title of the plant.

Berberis vulgaris.

--BERBERIDEÆ.--]

Viola tricolor.

--VIOLACEÆ.--]

=Wild Pansy= (Viola tricolor).

We have already given the general characters of the Violet family on page 4, where the reader was referred to this page for a notice of the British species other than V. odorata. The present species, V. tricolor, differs from all the others in the fact that the two upper petals are very erect instead of leaning forward, and in the stipules being developed into large leaf-like organs. In addition, this species produces none of the cleistogamous flowers. The leaves, too, assume forms very different from those of the typical species. The flowers vary from white, through yellow to purple, or there may be a mixture of two or more of these tints. They grow in pastures and the waste corners of various fields, flowering from May to September, and are generally distributed. The other species are:--

I. Marsh Violet (V. palustris). Growing among Sphagnum in bogs. Flowers lilac or white, scentless, and with short blunt spur. April to July.

II. Hairy Violet (V. hirta). Similar to V. odorata, but more compact, more hairy, the leaves narrower and more deeply toothed; spur long, hooked. Odour slight or wholly wanting. A local species occurring in dry soils. April to June.

III. Dog Violet (V. canina). Rootstock produced into a distinct stem, bearing flowers. Sepals narrow, pointed. Leaves not enlarging after flowering, as do those of V. odorata, palustris, and hirta; on long foot-stalks. Plant more or less smooth. Flowers from April to August, on banks everywhere.

IV. Wood Violet (V. sylvatica). Plant smooth. Central rootstock short, with a rosette of leaves, from which branches are given off all round. From these branches only are flowers produced. Spur short and broad. Leaves broad. Copses and woods. March to July. Often closely resembling V. canina, of which it may be only a variety.

V. Sand Violet (V. arenaria). A very rare, compact, hairy plant. Leaves much rounder than the preceding. Petals broad, pale blue. Spur short. Recorded from Upper Teasdale and Westmoreland only; flowering in May and June.

=Round-leaved Mint= (Mentha rotundifolia).

Everybody knows a Mint when he comes upon it, by reason of its pungent odour, well represented by Spear-mint (Mentha viridis), the cultivated herb of kitchen gardens. Spear-mint is held to be only a naturalized, not a native species, unless it be in one corner of our country--West Yorks. We have, however, seven species that may be set down as natives, but they are a rather troublesome group for the botanical student; there are so many varieties, hybrids, and sub-species, which tend to connect the species and make it difficult to determine the identity of some specimens. With the exception of the Corn-mint (M. arvensis), they are all inhabitants of wet and marshy wastes, flowering in August and September. They are Labiate plants, and therefore the reader will know what type of flower to expect (see pages 21 and 23 ante). These flowers are individually small, but rendered more conspicuous by being borne in dense whorls, the whorls being often so many and so close together as to form long spikes of bloom. They are all perennial herbs, with square stems and rootstocks, the latter creeping on or just below the surface of the ground, and giving off runners freely. Mentha rotundifolia has broadly ovate, wrinkled, stalkless leaves, the edges indented with rounded teeth, and woolly on the underside. Flower-spikes dense, though with slight intervals between the whorls. The colour of the flowers varies from pink to white. The other species are:--

I. Horse-Mint (M. sylvestris). Leaves stalkless, more tapering to a point than in M. rotundifolia, smooth above, sharply toothed, whitish beneath. Stem covered with white woolly hairs. Flowers lilac, spike continuous. Rare.

II. Peppermint (M. piperata). Leaves stalked, margins with large teeth, smooth above, a few hairs along the nervures underneath. Flowers purplish in spikes.

III. Water-Mint (M. aquatica). A very common form in marshes and by riversides, covered with soft hairs. Stout spikes, lilac or purple. Leaves stalked.

IV. Marsh-mint (M. sativa). In this and the two following species the whorls are produced from the axils of the leaves instead of as a terminal spike. The leaves are stalked, with sharp teeth. Flowers purplish. The throat of calyx smooth, calyx-teeth lance-shaped, ending in a fine point.

V. Corn-mint (M. arvensis). Leaves with blunt teeth. Calyx very hairy, teeth shorter than in last, triangular. Corolla hairy, purplish. Cornfields and waste places.

Mentha rotundifolia.

--LABIATÆ.--]

Symphytum officinale.

--BORAGINEÆ.--]

VI. Pennyroyal (M. pulegium). Calyx two-lipped, downy or hairy, with hairy throat. Leaves small, with short stalks, slightly toothed, recurved. Stem much-branched. Odour powerful.