LEAFLET XXXIV.
THE CLOVERS AND THEIR KIN.[46]
By ANNA BOTSFORD COMSTOCK.
The pedigree of honey does not concern the bee, A clover any time to him is aristocracy.
—Emily Dickinson.
There is a deep-seated prejudice that usefulness and beauty do not belong together;—a prejudice based obviously on human selfishness, for if a thing is useful to us we emphasize that quality so much that we forget to look for its beauty. Thus it is that the clover suffers great injustice; it has for centuries been a most valuable forage crop, and, therefore, we forget to note its beauty, or to regard it as an object worthy of æsthetic attention. This is a pitiful fact; but it cheats us more than it does the clover, for the clover blossoms not for us, but for the bees and butterflies as well as for itself. As I remember the scenes which have impressed me most, I find among them three in which clover was the special attraction. One was a well-cultivated thrifty orchard carpeted with the brilliant red of the crimson clover in bloom. One was a great field of alfalfa spread near the shore of the Great Salt Lake, which met our eyes as we came through the pass in the Wasatch Mountains after days of travel in dust-colored lands; the brilliant green of that alfalfa field in the evening sunlight refreshed our eyes as the draught of cold water refreshes the parched throat of the traveller in a desert. And another was a gently undulating field in our own State stretching away like a sea to the west, covered with the purple foam of the red clover in blossom; and the fragrance of that field settled like a benediction over the acres that margined it. But we do not need landscapes to teach us the beauty of clover. Just one clover blossom studied carefully and looked at with clear-seeing eyes, reveals each floweret beautiful in color, interesting in form, and perfect in its mechanism for securing pollination.
The clover is especially renowned for its partnerships with members of the animal kingdom. It readily forms a partnership with man, thriftily growing in his pastures and meadows, while he distributes its seed. For ages it has been a special partner of the bees, giving them honey for carrying its pollen. Below the ground it has formed a mysterious partnership with microbes, and the clover seems to be getting the best of the bargain.
For many years clover was regarded as a crop helpful to the soil, and one reason given was the great length of the roots. Thus the roots of red clover often reach the depth of several feet, even in heavy soil, which they thus aerate and drain, especially when they decay and leave channels. But this is only half the story; for a long time people had noted that on clover roots were little swollen places or nodules, which were supposed to have come from some disease or insect injury. The scientists became interested in the supposed disease, and they finally ascertained that these nodules are filled with bacteria, which are the underground partners of the clovers and other legumes. These bacteria are able to fix the free nitrogen of the air, and make it available for plant-food. As nitrogen is the most expensive of the fertilizers, any agency which can extract it from the free air for the use of plants is indeed a valuable aid to the farmer. Thus it is that in the modern agriculture, clover or some other legume is put on the land once in three or four years in the regular rotation of crops, and it brings back to the soil the nitrogen which other crops have exhausted. An interesting fact about the partnership between the root bacteria and the clover-like plants is that the plants do not flourish without this partnership, and investigators have devised a method by which these bacteria may be scattered in the soil on which some kinds of clover are to be planted, and thus aid in growing a crop. This method is to-day being used for the introduction of alfalfa here in New York State. But the use of clover as a fertilizer is not limited to its root factory for capturing nitrogen; its leaves break down quickly and readily yield the rich food material of which they are composed, so that the farmer who plows under his second-crop clover instead of harvesting it, adds greatly to the fertility of his farm.
The members of three distinct genera are popularly called clovers: The True Clovers (Trifolium), of which six or seven species are found in New York State, and more than sixty species are found in the United States. The Medics (Medicago), of which four species are found here. The Melilots (Melilotus), or sweet clovers, of which we have two species.
The True Clovers. (Trifolium.)
