2. Lotus tenuis—Slender-leaved Bird’s-foot Trefoil—is, perhaps, only a variety of the former; it is, however, smaller in all its parts, and, though a denizen of stiff soils, occurs chiefly in a wild state on the margins of fields and on hedge-banks. It might be employed under the same circumstances as the L. corniculatus, especially in thin clay-beds on upland brashes; but it hardly possesses such good qualities.
3. Lotus major—Larger Bird’s-foot Trefoil—is much larger in all its parts than the other species. It occurs in moist situations, about bushes in wet land, in ditches, watercourses, and damp places generally. We have experimented upon the growth of this plant in artificial meadows, and from the size which it attains quite early in summer, and the quantity of wholesome keep it is capable of affording, we are disposed to think well of it as an occasional shifting crop, or it might be well combined with rye-grass in deep stiff soils.
IV. Medicago—Medick, &c.
This genus is principally distinguished from Trifolium by its twisted seed-pods, which in the Medicago maculata (Spotted-leaved Medick) form quite a spiral coil, ornamented with a double fringe of stiff spines. This plant is now becoming general as an agrarian weed, having been greatly spread, owing to its intermixture with foreign seeds of different kinds.
The agricultural species are:—
Medicago lupulina—Yellow Sickle Medick.—“Hop trefoil” of the farmer, but not of the botanist, who gives this name to the Trifolium procumbens (which [see]). From this latter the medick is easily distinguished by its heads of naked, blackened, incurved seed-vessels. As an agricultural plant it is of great value, especially in mixtures called “seeds.” It is a good adjunct to rye-grasses and common clovers, especially on light soils; but on good strong land which will bear a full crop of broad-leaved clover it would be mostly smothered out, and, if not, as we think it is properly held to be less nutritious than clover, its use is not recommended where first-rate clover crops can be grown.
We have seen this trefoil grown with sainfoin to great advantage, as it yields a tolerable crop for the first two years, and then declines, just as the sainfoin has got possession of the soil.
2. Medicago sativa—Lucerne—is a perfectly perennial plant, which, though not so much grown in England as it deserves, yet scarcely needs description; however, its purple flowers and smooth twisted seed-pods serve to distinguish it from the rest of the genus. We have grown this plant upwards of a foot high by the 1st of May, and taken no less than three cuttings of a good succulent herbage in one season. These qualities point out lucerne as an excellent green-food plant, for which purpose we should always, where practicable, recommend that at least a patch should be grown near the stable, as there is reason to believe that its alterative effects upon the horses are of a most salutary kind. It should be cultivated in drills of from 15 to 18 inches apart; and, if properly weeded and not let get too old before cutting, it will last for many years with an occasional dressing of manure.
We once had a patch one half of which was purposely neglected by way of comparison with the other half, which was well cared for; that portion left to itself yielded but poor crops, and almost disappeared at the end of four years, whilst the other portion scarcely began to decline after ten years. This remark applies with full force to all the green-food crops of this order. Weeding early, mowing when cut, and an occasional top-dressing, would increase the durability of all the perennial species.