There is a widespread belief that nearly all plants yield nectar and are of more or less value to bee culture. Accordingly from time to time bumblebee-flowers, butterfly-flowers, moth-flowers, pollen-flowers, and wind-pollinated flowers are reported as excellent sources of nectar. It is not unusual to find bird-flowers, like the wild columbine, the torch-lily, the cardinal flower, and the trumpet honeysuckle in a list of honey plants. A great company of flowers, known as pollen-flowers, are wholly nectarless, and offer their insect visitors no other reward than an ample store of pollen. Several very common plants, as the yellow buttercup and the white daisy, yield floral food in such scanty amount that a bee is seldom seen on the bloom. The potato, the tomato, and the common garden pea, of which there are thousands of acres under cultivation every year, are practically valueless to the beekeeper. A more accurate knowledge of the flora of the United States is necessary.

Thousands of species are so rare as to be of no practical value to the beekeeper. Heather, or ling, which covers vast moors in western Europe, is found in America only locally in the coastal region of New England; while two other species of heaths have become established only in patches on Nantucket Island, Massachusetts. Many subtropical trees and shrubs have migrated into the southern portion of the United States from the warmer regions southward; for example, on the Rio Grande Plain of Texas there are nearly 80 small trees and shrubs, not one of which appears in the Atlantic forests of east Texas. There are scores of flowers which are not found outside of California, as many lupines, and species of Gilia and Sidcilcea. Alpine flowers are restricted to mountainous elevations, and many beautiful orchids live only in cranberry bogs. There is a very general impression that a large flower-garden is an excellent bee pasture; but many of the gaudy exotics of cultivation have either ceased to secrete nectar, or produce it in long tubular nectaries beyond the reach of honeybees.

There is a great company of bumblebee-flowers many of which are useless to the honeybee, as the larkspur, monkshood, snapdragon, turtlehead, bush honeysuckle, scarlet sage, the wood betony, and many handsome orchids. Red clover is also a bumblebee-flower, and under normal conditions honeybees do not resort to redelover fields, but in exceptionally dry seasons the floral tubes become so short that large yields of nectar are obtained. At Borodino, N. Y., this has happened twice in thirty years. In the fertile limestone soil of western Ohio and eastern Indiana nectar is secreted so abundantly by red clover and the bumblebee horsemints that a portion of it is accessible to honeybees. Not infrequently, in their haste to obtain the nectar, bumblebees bite holes in the spurs of flowers. The tubular nectaries of the fly-honeysuckle, the garden columbine, the skullcap, and the jewelweed are