CHAPTER XVII.
ON THE NATURE AND PROPERTIES OF THE CLOVER FAMILY OF PLANTS.
Clovers are admitted by all to be such important adjuncts to the fodder plants of the farm as to render a scientific and practical treatise upon them and their allies a matter not only of interest, but of general agricultural utility; for, if we except the grasses, perhaps no natural order of plants is of greater value to the farmer than that to which the clovers belong; for, though they differ in every point of their structure, yet in their farm products they offer an interesting analogy. Thus, whilst in the Graminaceous plants we have cereal or corn-seed products, and meadow and pasture herbs, in the Leguminous plants we have a seed-producing group termed pulse, and a herb-growing green-food or fodder series. On either hand, in both groups, there are differently-cultivated forms; for, while the grass-cereals are wholly the result of arable culture, the fodder grasses are for the most part grown under conditions distinguished by the farmer as pasture. So of leguminous plants, pulse, such as peas and beans, belongs exclusively to the arable part of the farm; but the fodder kinds, as clover, either mix with the grass of the meadow, or are grown by themselves or with grasses in shifting green crops: indeed, it is by reason of clovers eking out grass, or being used as pasturage, that they have come to be designated “artificial grasses.”
The tribe of plants under review forms an exceedingly natural group, which has been named Papilionaceæ, from the fancied resemblance in the arrangement of its flowers to the form and varied colouring of butterflies: by others it is designated Leguminosæ from the two-valved seed-pod, which by the botanist is termed a legume,—most perfect examples of which are seen in the fruits of our more ordinary pea and bean.
Though the flowers of the group are infinitely varied in size and in colour, yet they afford most permanent characters in their irregular petals, which, after all, have the same parts in the variously coloured and showy sweet-pea as in the most minute clover; so that, once examine the pea or bean, and the significance of the name of the order depending upon the flowers, will be easily understood. Again, varied as is the seed-pod, yet a little examination will show that its type is simple, there being no structural difference between the straight legume of the pea and the spirally-twisted one of the lucerne and medicks, or the many-seeded smooth pod of the common broom and the single-seeded wrinkled pod of the sainfoin.
The seeds, again, may vary in colour; some, like those of the scarlet-runner, are curious as affording an infinite variety of self-colours for their different sorts, from pure white to absolute black; or these may be so pencilled as to make a testa or seed-covering as variously mottled as are the eggs of some of our birds. Yet, whether rounded as in the pea, flat as in the bean, lenticular as in the lentil, or kidney-shaped as in the clovers, they are all readily referred to one group by the flat, oval eye (hilum of the botanist), and the fact of their ready capability of separating into two valves (cotyledons), so observable in our split peas and beans.
But of all the varieties in their parts presented by the pea-flowered tribe of plants,—if we except the fact that some are larger trees, as the locust tree, ebony, laburnum, &c., whilst some are among our smallest plants, as clovers and medicks,—the principal differences will be found in the foliage. The grass vetchling, for example, is so named from its leaves being not unlike those of grasses, while the yellow vetchling, in its mature state, has the whole leaf converted into a tendril and the appendages at the bases of the leaves (stipules) are so enlarged as to be often mistaken for leaves: in another of the vetchlings, the everlasting sweet-pea, we find that, as so much of the leaf is converted into tendrils to enable this handsome plant to climb over the hedges and thickets, the stem is made four-winged with leaf-matter, to ensure the due performance of the leaf function. Now parts called stipules are present in this whole tribe, and, like all other parts of these plants, they vary in form, size, and markings, and hence afford important aid in the discrimination of species. Again, the old furze-bush will have its leaves converted into spines, though the seedling started with a trifoliate leaf. Points like these, however, though most interesting to the student of vegetable physiology, are beyond the scope of the present work.
Like every other point connected with this interesting natural order of plants, their uses and properties are greatly varied, and perhaps variable. The Sennas are renowned for their medicinal properties, being in some kinds aromatic and purgative. A powerful aroma is given off from the Melilots, similar to that of the well-known sweet vernal grass (Anthoxanthum odoratum), on which account it has been recommended to mix a little of their seeds with clovers, or to cultivate separate patches of either the white or the yellow Melilot to place here and there, sandwich-wise, in the clover hay-rick.
In speaking of this matter of flavour in food for cattle, we may here mention that the seed of one of this order, which is now being extensively employed for its flavouring principle, is the Fœnugræc (Trigonella fœnum-græcum), which was formerly used in large quantities by horse and cattle doctors as an ingredient in drenches or drinks for horses, cows, and pigs. Latterly, however, it has been still more largely employed as a flavouring matter in the different kinds of “Cattle Feeds.”[5]
[5] We have cultivated these seeds in England, and found them to ripen very well, and if the flavouring of food be correct in principle, the seeds might readily be ground with feeding stuffs, while the dried plant could be mixed with hay and straw in chaff.
Now, whether medicinal properties reside as a rule in all of the order, it would perhaps be difficult to determine; but, as we sometimes find that certain clover crops are accused of causing “scouring,” there is perhaps reason to conclude this, but that its amount varies according to season, soil, and cultivation.