The Leguminosae of the world includes some twelve to fifteen thousand species and is surpassed in numbers by only one other plant family, the Compositae, with about twenty to twenty-five thousand species. The grasses of the world, so important agriculturally, embrace probably 10,000 species, and great expanses of grassland in every continent constitute one of the world's major vegetation types. Legumes and composites, however, usually occur as scattered secondary components of the native vegetation. Although no exhaustive check list has recently been compiled, it is estimated that there are nearly 2,000 species of leguminous plants native to the United States. Many foreign species are naturalized here, and about 50 legumes, mostly introduced, are grown in this country as commercial crop plants. Many exotic and some native legumes are cultivated as ornamentals.

The large number of leguminous plants to be found in the United States necessitated some selection for consideration in this publication. Strictly ornamental plants are excluded. The species treated are: (1) Those that have actually been used to control erosion or are unusually promising for their erosion-control value; (2) those with known records of use by wildlife; and (3) those of significance to the soil and wildlife, conservationist for some other particularly pertinent reason. However, both native and introduced legumes in all parts of the United States have been considered in compiling the list. About 400 species are treated in this publication, 128 of which are illustrated. Any legume not listed may be considered to have no erosion-control or wildlife values which have come to the author's attention.

The list presents information about legumes and their usefulness in soil and wildlife conservation. It is not a nursery handbook, nor is it a botanical manual. For identification the reader must refer to manuals covering the region in which lie is working; consequently, no keys are included and only synoptic facts of botanical description, growth, and range are given. Time of flowering and fruiting likewise vary greatly, and notes on these characteristics can be useful only when obtained locally. Among native herbaceous species, information regarding site requirements is not always at hand, but it has been given if known. Since herbaceous legumes are generally grown from seed rather than from nursery stock propagation notes are given only in special instances, as when propagation is by root crown or when some unusual treatment is required.

For each plant species listed, utilization by wildlife is divided into stomach records, given first, and observations. Stomach records refer to contents found in crop, gizzard, stomach, cheek pouch, or droppings, but not to food in caches. Unless otherwise noted, the stomach records have been obtained from files of the Section of Food Habits Research, Fish and Wildlife Service. Observations are largely from the literature, and sources are cited in each instance. If an animal is known by both stomach record and observation to eat a legume, that animal is listed only under stomach records; its name is not duplicated under the observations. Observations are sometimes derided as being less exact than stomach records, but they may be reliable, especially if the plant that is eaten and the animal observed are carefully identified. Observations are particularly useful in the case of herbage or fleshy fruits that may be unidentifiable in stomach contents.

What Barrows has written of the robin is surely true of many other animals. He states:

It is a remarkable fact that no extended investigation of the Robin's food, based upon stomach contents, has indicated more than a very small proportion of earthworms, less than 2 percent being the maximum record so far as we can find. On the other hand, it is a matter of common, almost universal, observation that the robin during spring and early summer, and again for a considerable time in autumn, feeds very largely upon earthworms. The writer has seen a Robin extract from the ground and eat or carry away for its young ten or a dozen worms in as many minutes, and observations made continuously for many seasons here in Michigan have convinced us that the first brood of young under ordinary conditions is reared very largely upon this diet. This is not due to the entire absence of other food, but merely to the fact that the earthworms are abundant, easily obtainable, and in no way objectionable as food for the young or old. This disparity between the results of observation in the field and stomach examination in the laboratory suggests the probability that there is yet much to be learned in regard to the food of the Robin.

The number of records existing for each animal listed is not given. From this paper one cannot tell whether 1 bird ate 1 seed of a particular plant or 1,000 birds ate 500 seeds each. This may at first seem to be a very serious difficulty with the present report. As stated above, however, the frequency of occurrence of food items in a bird's stomach may only reflect availability of the food. McAtee early pointed out. that numerical systems alone are not sufficient, but must be combined with volumetric (percentage-by-bulk) methods to indicate the true value of stomach contents as evidence of the food preferences of a given animal. Later McAfee, thinking of the multitude of foods available and the limited number of stomach analyses, stated:

It often occurred to me as I conned the tabulations that, all things considered, a single record of a given species might be as much as could be expected.

This statement does not apply where intensive studies have been made, as with doves and various quail, but until our knowledge of food habits, now largely recorded at random, is based on careful life history studies, we must content ourselves with fragmentary records.

There are many reasons why the wildlife manager should not interpret too literally the known facts about animal foods. Collections or observations may be limited to a locality where a particular plant species is sufficiently abundant to form a large proportion of an animal's food, Yet, if sufficient records were available from the entire range of the animal, that particular plant food might then be shown to be of slight relative significance so far as that animal species is concerned. Therefore it would seem important to attempt to interpret food records with respect to the entire range of an animal and to relate its range to the natural range or abundance of the food plant concerned. Furthermore, the quantity of food eaten may be no indication of the actual nutritional value, of the food. The time of year a bird or mammal is collected likewise influences the significance of stomach records. Continued study and experiment will eventually provide a true picture of this relationship. In the meantime, it is believed that the records set forth here, even without qualifying statements, may serve as general indicators of the value of legumes to animals. To the wildlife manager interested in all wildlife, other things being equal, the plant with the longest roster of animals known to use it is likely to be considered the most important.

Jason Ladock

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