820 CONVOLVULACEAE (CONVOLVULUS FAMILY) 
Fig. 222. — Black Swal- 
low-wort (Cynanchum ni- 
grum). Xi. 
Native. 
This plant, like the preceding one, is 
often called Climbing Milkweed ; the milky 
juices are poisonous. It is an immigrant 
from Europe, first planted in gardens for 
its beauty; but the silken-winged seeds 
made an easy escape and now the weed is 
a frequent nuisance in ground not under 
cultivation. (Fig. 222.) 
Stems twining, slender, three to six feet 
long, slightly hairy, often brownish red 
where exposed to the light. Leaves op- 
posite, long-ovate, thin, dark green, smooth, 
entire, pointed at tip and rounded at base, 
with prominent, sometimes reddish, veins 
and short petioles. Flowers in axillary 
cymose clusters, small, saucer-shaped, the 
five spreading lobes somewhat twisted, 
hairy within, deep purple; peduncles 
shorter than the leaves. Follicles about 
two inches long, pointed at both ends, 
smooth. Seeds flat, brown, tipped with 
silken floss. 
Means of control the same as for the 
preceding species. It is more pernicious, 
and requires persistent treatment. 
WILD SWEET POTATO VINE 
Ipomea panduraia, G. F. W. Mey. 
Other English names: Man-of-the-Earth, Mecha-Meck. 
Perennial. 
Propagates by seeds. 
Time of bloom: May to September. 
Seed-time: Late June to October. 
Range: 
Eastern Canada and New England to Michigan and 
Kansas, southward to Florida and Texas. 
Habitat: Dry soil; thickets and waste places. 
The very large fleshy roots of this plant are edible and sweet, 
and are buried very deep in the ground below the reach of frost; 
