RUBIACEAE (MADDER FAMILY) 399 
spatulate, bristle-pointed, the margins and midribs also bristly 
with short, stiff hairs. Flowers similar to the preceding species in 
structure, white, minute but very numerous, in open cymose clusters 
at the ends of the many branches and in the upper axils. The twin 
fruits are smooth. 
Means of control 
Hand-pull the vines when in first bloom. If the patches are not 
too numerous, it will pay to grub out the roots and save further 
trouble. 
SMOOTH BUTTONWEED 
Spermacoce glabra, Michx. 
Native. Perennial. Propagates by seeds. 
Time of bloom: June to September. 
Seed-time: August to October. 
Range: Ohio to Illinois, southward to Florida, 
Arkansas, and Texas. 
Habitat: Wet meadows, banks of streams, 
and ditches. 
Stem ten to twenty inches tall, rather 
stout, smooth, four-sided, sometimes simple 
and erect or often diffusely branched, the 
branches spreading, the lower ones decum- 
bent. Leaves one to three inches long, 
opposite, their bases connected by bristly, 
membranous stipules, entire, elliptic, pointed 
at each end, with smooth surface but rough 
edges. Flowers in dense terminal and axil- _ Fic. 278.—Smooth 
lary whorled clusters, the corollas funnel- Buttonweed  (Sperma- 
- coce glabra). X %. 
form, four-lobed, white, less than a quarter- 
inch long; stamens four, inserted on the tube; style two-cleft ; 
calyx also four-lobed, its acute teeth persistently crowning the 
fruit, which is two-celled; when ripe the carpels separate, one 
carrying with it the partition, leaving the other bare on the inner 
face. Seeds small, hard, black, oblong to wedge-shaped, rounded 
on the back, with flat inner face; too often an impurity of southern 
grass and clover seed. (Fig. 278.) 
