LEGUMINOSAE (PULSE FAMILY) 233 
“soil renovators,” partly by reason of their large and deeply 
penetrating roots, which break up the soil, mellow, aérate, and 
drain it, and then, by their death and rapid decay, furnish it with 
humus; also they bear on their roots many tubercles in which live 
those beneficent, nitrogen-gathering bacteria that make the earth 
better for their having lived in it. For this reason, Sweet-clover is 
often used to prepare the ground for the growing of Alfalfa. The 
hay is nutritious, but cattle do not like its 
strong odor and will not eat it until they have 
been “educated to the taste,” which is usually 
done by turning them into the Sweet-clover 
field early in spring, when no other green 
forage is available. (Fig. 165.) 
Stems three to ten feet tall, round, slender, 
somewhat woody, many-branched, smooth 
except the young growing twigs, which are 
finely hairy. Leaves pinnately three-foliolate, 
the leaflets oblong to elliptic, obtuse or some- 
times even notched at .the tip, very finely 
toothed, the foot-stalk of the middle one 
bent slightly upward ; petioles usually shorter 
than the blades. Flowers in long, slender, 
one-sided, axillary racemes, white and very 
fragrant; corolla about a quarter-inch long, 
with narrow petals, the standard longer than 
the wings or the keel. Pods ovoid, wrinkled, 
net-veined, one- or two-seeded. When in the 
soil the seeds are said to retain their vitality ie. 165. — White 
for fifty years or more; they are sometimes Sweet-clover (Melilo- 
used by unscrupulous dealers for the adulter- tus alba). ih 
ation of Alfalfa seed, which is somewhat similar in appearance 
but much more expensive. 
Means of control 
Close cutting as soon as the first flowers open; the plants will 
immediately sprout thick stools of flowering stalks, requiring a 
second and perhaps a third cutting, but if no seed is allowed to 
mature and drop into the soil there will be no further trouble, for 
