CHAPTER XIX.
ON THE VARIETIES OF RED CLOVERS.
The Trifolium pratense of botanical authors is remarkable for the great number of varieties it assumes, even in its wild growth; but these are exceeded in the number of cultivated forms: thus in any rich meadow we may make out several sorts which may be expected to be more or less permanent, whilst the market samples of seed will offer us several varieties for the different countries of America, England, France, Holland, Germany, &c.
The following are some of the more prominent of our native wild varieties:—
1. Trifolium pratense—Common Red Clover.—Head of pink; flowers, somewhat compact; leaves more or less broad; plant smooth[7] in proportion to its size, the smaller wild specimens being usually very hairy; stem more or less purple.
2. Trifolium pratense, var. pallidum—Pale-flowered Clover.—Head of very light pink; flowers large, full, and more rotund than 1, and almost double in size and in the number of its flowers; whole plant more or less hairy; stem green.
3. Trifolium pratense, var. album—White Clover.—Flowers white; herbage a very light green; in other respects much the same as the last.
4. Trifolium pratense perenne—Perennial Red Clover.—Flowers less compact than the common clover, whole plant having stems inclining to dark purple; leaves narrower.
[122]5. Trifolium pratense perenne, sub-var. pallidum—Pale Perennial Clover.—A larger plant than the parent form, and less hairy.
6. Trifolium pratense perenne, sub-var. album—White Perennial Clover.—Not common, but still, like 3, an albino form, and is, perhaps, more delicate in constitution than the coloured sorts.
[7] In this, as well as the generality of forms, the smoother and larger growth indicates cultivation, manuring will sometimes make the difference.
Now, it appears to us that the descendants of the two types, Trifolium pratense and T. medium (see [Plate]) form the basis of the red or broad-leaved clover on the one hand, and the perennial or cow-grass clover on the other; whilst the market varieties have, perhaps, been modified by climate, soil, and probably hybridization with other sorts. It may, indeed, be that, after all, the plants described in [chapter XVII.] as two distinct species are only varieties, for though the common form of T. pratense grows everywhere on mixed soils, the more sandy positions, as the sandstones connected with the coal in South Wales, offer a greater abundance of the T. medium; and, from experiments conducted with seed of this latter obtained from near Swansea, Glamorgan, and sown on forest marble clay of the Cotteswolds, we certainly obtained plants differing very much from the typical form of T. medium, and assuming the usual broad-leaved clover variations.
Here, then, is opened up a curious subject for inquiry, which the history of the seed trade as it relates to clover-seed may tend in some measure to elucidate. Some few years ago T. pratense and T. medium were advertised as on sale by most seedsmen; in fact, the latter was the name by which what is now called cow-grass clover was known. Now, however, it is doubtful if any seedsman would pretend to send out the T. medium; but the label T. pratense perenne has been substituted for it.