MILKWEED FAMILY 499 
shaped, tapering at each end, thin, 2 to 6 in. long, 4 to 24 in. wide, on 
short leaf-stalks. Flowers in 1 to 4 terminal umbels (rarely some small 
umbels in upper axils), pink or white. Woods and thickets. May-July. 
12. A.syriaca, L. (Fig. 1, pl. 124.) Common Minkweep. Stem 
stout, branching little, if any, slightly downy above, 3 to 5 ft. high. 
Leaves opposite, oblong or oval, blunt at each end, densely downy beneath, 
4 to 9 in. long. Flowers dull green-purple to whitish, in numerous um- 
bels. Fields, rich grounds. June-Aug. 
13. A. verticillata, L. (Fig. 7, pl. 123.) Wwortep Mirkweep. Stem 
slender, sometimes branched, leafy, 1 to 23 ft. high. Leaves linear in 
whorls of 3 to 7 or more. Flowers in terminal umbels, greenish-white. 
Dry hills, New York and southward. July-Sept. 
2, ACERATES, Ell. 
Herbs similar to Asclepias, but the hoods compassing the crown are 
without the horn which is characteristic of Asclepias. 
A. viridiflora, Eaton. (Fig. 8, pl. 123.) GReEN MILKWEED. Stem 
whitish, downy, at least when young, without branches, reclining or nearly 
erect, 1 to 3 ft. high. Leaves opposite, or, less frequently alternate, egg- 
shaped, on short leaf-stalks, thick, 1 to 3 in. long, 4 as wide, slightly 
rough, base rounded, upper blunt. Flowers in axillary umbels, green. 
Pod long and slender. Dry sandy soil. June-Sept. 
3. CYNANCHUM, L. (Vincetoxicum, Moench) 
A trailing vine, with opposite or whorled leaves and umbels of small 
flowers which resemble those of Asclepias. Calyx and corolla wheel- 
formed; crown cup-like, not divided into 5 distinct parts as in Asclepias, 
but has 5 lobes. 
C. nigrum, Pers. Brack SwaLLow-wort. Twining vine, 2 to 5 ft. 
long, with lance egg-shaped leaves, rounded at base, tapering at apex. 
Flowers dark purple. Pod slender, resembles that of Asclepias. Escaped 
from gardens. June-Sept. 
Order V.—TUBIFLORALES. Order of Tubular Flowers 
Flowers almost always regular, the corolla of a single envelope 
more or less parted into 5 lobes at the border. Stamens 5 inserted 
with the corolla and alternating with its lobes. Seed pods (car- 
pels) 2 to 5, always above and free from the calyx. Style nearly 
always simple. 
Ovary deeply 4-lobed. 
Corolla regular (except in Genus Echium), pods (car- 
pels) separating as nutlets. Herbs, not trailing or 
wine, WINES 2. . . ~ .\. =: ~BS.ORAGINACEAE 
Ovary not 4-lobed. 
