340 BORAGINACEAE (BORAGE FAMILY) 
brownish gray, wrinkled, pitted, and hard as 
stone, whence one of the common names; they 
are a common impurity of poorly cleaned wheat 
and rye, and also of timothy and alsike clover. 
" (Fig. 236.) 
Means of control 
Sow clean seed. Where the appearance is 
new and the areas small enough to permit of 
hand-pulling, that operation pays because it 
saves the soil from befoulment. Spray infested 
grain fields with Iron sulfate or Copper sulfate 
when the first blossoms appear. Burn over 
stubbles for the purpose of destroying seeds 
on the surface. Drop winter wheat and rye 
Si 236. — from the rotation until a cultivated crop has 
eat-thief (Li- 
thospermum ar- been grown on the land for the purpose of 
vense). X 2. stirring dormant seeds into growth. 
COMMON GROMWELL 
Lithospérmum officinale, L. 
Other English names: Pearl Plant, Graymile, Littlewale. 
Introduced. Perennial. Propagates by seeds. 
Time of bloom: May to August. 
Seed-time: July to September. 
Range: Quebec to Minnesota, southward to New Jersey. 
Habitat: Fields, pastures, roadsides, and waste places. 
Cattle refuse to eat these rough-hairy plants, though people are 
said to have used the leaves as a substitute for tea in Revolution- 
ary times. Root deep-boring, pinkish white, spindle-shaped. 
Stems one to three feet high, erect, much branched, and leafy to 
the summit. Leaves broadly lance-shaped, pointed at both ends, 
rough-hairy above, downy underneath, entire, and _ sessile. 
Flowers cream-colored or greenish white, very small, on very short 
pedicels in the upper axils; corolla funnel-form, five-lobed, with 
five hairy crests in the throat; calyx rough-hairy, with narrow, 
