This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Asclepias tuberosa L. Sp. Pl. 217. 1753.
Hirsute-pubescent; stems stout, simple, or branched near the summit, ascending or erect, very leafy, 1°-2° high, the milky sap scanty. Leaves alternate, lanceolate or oblong, acute or sometimes obtuse at the apex, narrowed, rounded or cordate at the base, sessile or short-petioled, 2'- 6' long, 2"-12" wide; umbels cymose, terminal, many-flowered; peduncles shorter than the leaves; pedicels 1/2'-1 long; corolla-segments about 3" long, greenish orange; corona-column about \" long; hoods erect, oblong, bright orange, or yellow, 2-3 times as long as the stamens, longer than the filiform horns; fruiting pedicels decurved; follicles nearly erect, finely pubescent, 4'-5' long.
In dry fields, Maine and Ontario to Minnesota, Florida, Texas, Chihuahua and Arizona. Consists of numerous races, differing in shape and size of the leaves and color of the flowers. June-Sept. Wind-or orange-root. Canada-, flux-, tuber- or white-root. Orange swallow-wort. Yellow milkweed. Indian-posy.
Asclepias decumbens L. Sp. Pl. 216. 1753.
Hirsute-pubescent; stems decumbent, 2°-3° long, the ends ascending or erect. Leaves sessile or short-petioled, oblong or elliptic, obtuse at the apex, narrowed and often inequilateral at the base, 1'-3' long, 1/2'- 21/2' wide, the upper opposite, the lower commonly alternate, the uppermost very small; umbels several or numerous, many-flowered, racemose along the branches, one usually in each of the upper axils; peduncles stout, short; pedicels slender, pubescent, about i' long; corolla-segments oblong, acutish, dark orange, about 3" long; column about i" high, the hoods erect, oblong, orange, longer than the subulate horn; follicles slender.
In dry fields, Illinois and Ohio to North Carolina and Florida. Creeping milkweed. June-Aug.
Asclepias lanceolata Walt. Fl. Car. 105. 1788. A. paupercula Michx. Fl. Bor. Am. 1: 118. 1803.
Glabrous; stem slender, usually simple, naked above, 2°-4° high. Leaves opposite, distant, linear or narrowly lanceolate, elongated, acuminate, narrowed at the base, short-petioled, 4'-10' long, 2"-7" wide, roughish on the margins, the primary nerves widely spreading; umbels few-flowered, solitary or 2-4 at the summit; peduncles about equalling the slender puberulent pedicels; corolla-segments oblong, 4"-5" long, deep red; column thick, about 1" high; hoods obovate or oblong, obtuse, orange, 2-toothed near the base, nearly twice the length of the anthers and longer than the subulate incurved horn; fruiting pedicels decurved; follicles erect, minutely puberulent, fusiform, about 4' long.
In swamps, southern New Jersey to Florida and Texas, mostly near the coast. June-Aug.