GENUS i. 



MILKWEED FAMILY. 



29 



13. Asclepias exaltata (L.) Muhl. Poke or 

 Tall Milkweed. Fig. 3395. 



A. Syriaca var. exaltata L. Sp. PI. Ed. 2, 313. 1762. 



Asclepias exaltata Muhl. Cat. 28. 1813. 



A. phytolaccoides Pursh, Fl. Am. Sept. 180. 1814. 



Nearly glabrous throughout, with two opposite 

 lines of pubescence on the usually simple stem, 3-6 

 high. Leaves opposite, thin or membranous, oval, 

 ovate or oblong, acuminate at both ends, 4'-9' long, 

 ii'-4' wide, the lower sometimes obovate, obtuse, 

 shorter; petioles i'-i' long; peduncles i'-3' long; 

 umbels usually several ; pedicels slender, drooping 

 or spreading, i'-2' long, puberulent ; corolla green- 

 purple, the segments ovate or oblong, obtusish, 

 3"-4" long; column short; hoods white or pink, 

 slightly shorter than the anthers, much shorter than 

 the subulate horn, at the summit truncate and entire 

 or erose, with i or 2 slender teeth on each of the 

 inner margins ; follicles erect on the deflexed pedi- 

 cels, downy, long-acuminate, 4'-6' long. 



hi thickets and woods, Maine to Minnesota, Georgia, 

 Missouri and Arkansas. Ascends to 5500 ft. in North 

 Carolina. June-Aug. 



14. Asclepias variegata L. White Milk-weed. Fig. 3396. 



Asclepias variegata L. Sp. PI. 217. 1753. 



Stem glabrous below, pubescent above when 

 young, simple, i-3 high. Leaves opposite, thick, 

 oval, ovate, oblong or the lower somewhat obo- 

 vate, obtuse and cuspidate or acutish at the apex, 

 narrowed or rounded at the base, dark green 

 above, pale beneath, 3'-6' long, i'-3' wide, the 

 middle ones sometimes verticillate in 4's ; petioles 

 3"-i2" long ; umbels 1-4, terminal, or rarely I or 

 2 in the upper axils, densely many-flowered; pe- 

 duncles i '-2' long; pedicels i'-ii' long, erect or 

 ascending, usually densely puberulent; corolla- 

 segments ovate or oval, about 3" long, white, or 

 purple near the base; column very short and 

 thick, purplish ; hoods globose-obovoid, obtuse, 

 spreading, longer than the anthers, about equal- 

 ling the semi-lunate horizontally pointed horn; 

 follicles downy, erect on the deflexed fruiting 

 pedicels, 4'-$' long. 



In dry woods or thickets, Connecticut (?), south- 

 ern New York to Illinois, Arkansas, Florida and 

 Texas. June-July. 



15. Asclepias quadrifolia Jacq. Four- 

 leaved Milkweed. Fig. 3397. 



A. quadrifolia Jacq. Obs. Part 2. 8. pi. 33. 1767. 



Stem slender, simple, i-2 high, usually leaf- 

 less below. Leaves thin, sparingly pubescent on 

 the veins beneath, ovate to lanceolate, 2'-6' long, 

 \'-2\' wide, acute or acuminate, narrowed or 

 rounded at the base, or the lowest pair much 

 smaller, obovate and obtuse, the upper and lower 

 opposite, the middle ones usually verticillate in 

 4's ; umbels 1-4, terminal, or rarely in the upper 

 axils; peduncles slender, \'-2\' long; pedicels 

 about i' long; corolla pink or nearly white, its 

 lobes lanceolate-oblong, 2"-$" long ; column short ; 

 hoods white, obtuse at the apex, broadly 2-toothed 

 above the base, twice as long as the anthers and 

 the short incurved horn ; follicles erect on the 

 erect fruiting pedicels, 3'-$' long, glabrous. 



Woods and thickets, Maine and Ontario to Minne- 

 sota, Alabama and Arkansas. May-July. 



