MILKWEED FAMILY. ASCLEPIADACEAE.
Fig 140.[Common Milkweed. Asclepias Syriaca] L.
![[Common Milkweed. Asclepias Syriaca]](#1525880611323293367_fig-140.jpg.id-8106295148022168682.wrap-0.html.html){kind=link}
Common Milkweed. Asclepias Syriaca L. Pods 8–12 cm. long, covered with soft spiny processes; seeds dull light brown, much flattened, narrowly obovate, 6.5–8 mm. long, the small end truncate, surrounded by a broad wrinkled wing-margin or hem. The concave side bears a slender vertical ridge (raphe) for two-thirds of its length; the convex side bearing fine, short ridges. Before escaping from the pods, the small end of the seed contains a cluster of spreading silky hairs (coma) 2–3 cm. long. Native of this country. Often troublesome and conspicuous in light soil, occasionally becoming small, pale, with slender branches and dying.
Fig 141. [Black Swallow-wort. Cynanchum nigrum] (L.) Pers. Vincetoxicum nigrum Moench.
![[Black Swallow-wort. Cynanchum nigrum]](#1525880611323293367_fig-141.jpg.id-4497281048039064698.wrap-0.html.html){kind=link}
Black Swallow-wort. Cynanchum nigrum (L.) Pers. Vincetoxicum nigrum Moench. Smooth pods of the vine about 5 cm. long; seeds brown when dry, much flattened, concave, obovate, 6–8 mm. long, nearly surrounded by a wing margin or hem, the small end truncate. The concave side bears a slender vertical ridge (raphe) for over half its length, both sides bearing fine short ridges. Before escaping from the pods, the small end of the seed contains a cluster of spreading silky hairs. Introduced from Europe; not yet common, but it is persistent where once started.