The danger of overstocking is largely imaginary, yet in establishing a large apiary it is of course essential to look to the natural resources of the location, and especially to decide only upon a place where two or more of the leading honey-producing plants are present in great numbers. In the North, willows, alder, maples, dandelion, fruit blossoms, tulip tree (frequently called whitewood), locust, clovers (white, alsike, crimson, and mammoth red), with alfalfa and melilot, chestnut, linden or basswood, Indian corn, buckwheat, fireweed, willow-herb, knotweeds, mints, cleome, golden-rods, Spanish needle, and asters may be cited as the chief sources of pollen and honey; and of these the tulip tree, locust, white clover, alfalfa, melilot, linden, and buckwheat furnish most of the surplus honey. The fruit blossoms, with the exception of raspberry, come so early that a small proportion only of the colonies are sufficiently strong to store surplus, and of course this statement applies with still more force to plants which blossom before apple, pear, cherry, etc. Some of the clovers, mustard, rape, cultivated teasel, chestnut, barberry, sumac coral berry, pleurisy root, fireweed, borage, mints, willow-herb, Spanish needles, cleome, etc., though yielding well, are only found abundantly over certain areas, and do not therefore supply any considerable portion of the honey that appears on the market, though when any of them are plentiful in a certain locality the bee keeper located there will find in nearly all cases that the surplus honey is greatly increased thereby. [Illustration: Fig. 44.--Willow herb (_Epilobium angustifolium_). A, young flower: _s_, stigma turned back: _a_, anthers; _l_, lobe or pod. B, older flower: _s_, stigma turned forward; _a_, anthers: _l_, lobe. C, spike of flowers. D, section of pollen grain: _e_, extine; _i_, intine; _ti_, thick intine; _f_, fovilla. E, growing point of pollen grain: _e, e_, extine; _i, i_, intine; _f_, fovilla; _pt_, pollen tube. (From Cheshire.)] In the middle section of our country, from Maryland, Virginia, and North Carolina westward, most of the sources named above are present, although the maples (particularly hard maple) furnish less, and fruit bloom, the clovers, linden, and buckwheat are not as great yielders as in the North. Sourwood or sorrel tree, mountain laurels, sour gum or tupelo, huckleberry, cowpea, magnolia, and persimmon make up in part for these, the sourwood being especially important, while in some localities certain species of asters yield very abundantly. The tulip tree (known commonly as poplar) is a greater yielder than in the North, while in the western portion of the middle section the Rocky Mountain bee plant or cleome and more extensive areas of alfalfa and melilot are very important sources.