64 BULLETIN 428, U. S. DEPARTMENT OF AGRICULTURE. 
The species was recognized by botanists early in the history of 
modern botany, if not long before. Recent botanists differ somewhat 
with regard to its taxonomic relationship to Medicago sativa. Some 
give it the rank of a true species, while others regard it as a variety 
or subspecies of the latter. The natural relationship of the two, 
however, is quite clearly shown by the readiness with which they 
hybridize and the fertility of their hybrids. 
It is an extremely variable species, many forms of which are diffi- 
cult to classify satisfactorily on account of their varying combina- 
tions of characters and the difficulty of determining whether they 
are of pure or hybrid origin. A classification or grouping has been 
attempted in this paper largely upon the basis of habit of growth. 
Four groups have been established, ranging in habit from prostrate 
to almost erect. The first two are referred to as pasture groups, as 
they are not sufficiently erect to be harvested satisfactorily for hay 
by machinery. The last two are sufficiently erect to be harvested for 
hay and are referred to as hay groups. 
Botanists have named and described several varieties of the 
species, many of which have proved to be hybrids of Medicago 
falcata and Medicago sativa. | 
Medicago falcata has never been extensively cultivated in Europe 
or Asia, although it has been utilized as a wild forage plant since a 
very early date. Many attempts have been made to grow it under 
cultivation in Europe, but so far as can be found it is now being 
cultivated only in India and, possibly, to a very limited extent in 
southeastern Russia and Chinese Turkestan. | 
Numerous common names have been proposed for the species, but 
so far none is satisfactory. The name by which it is most gen- 
erally known in this country is yellow-flowered alfalfa. It is prob- 
able that this name will finally be adopted. 
The erect forms of Medicago falcata resemble very closely those 
of Medicago sativa in their mass effect, but on an average they pro- 
duce a heavier yield in comparison with their bulk, partly because 
of the more numerous stems and partly because of the texture of 
their herbage. Under similar conditions of soil and stand of plants 
the best strains of Medicago falcata frequently outyield the best 
varieties of Medicago sativa for the first cutting of the season. 
A very serious drawback to the general utilization of Medicago 
falcata as a cultivated forage crop is its inability to recover quickly 
after cutting. Under conditions such as exist in the West and 
Northwest, where it appears to offer its greatest possibilities, it can 
be depended upon to make only one crop in a season. It produces 
seed sparingly and does not hold it as retentively as does Medicago 
sativa. This is also a serious handicap to its use as a cultivated crop. 
