352 ASCLEPIADACE^E. (MILK-WEED FAMILY). 



2. A. Sllllivsaaatii, Engelrn. Mss. Very smooth throughout, tall; leaves 

 ovate-oblong from a heart-shaped nearly sessile base ; hoods of the crown obovate, 

 entire, obtusely 2-earcd at the base on the outside, with an incurved and flat 

 claw-like horn ; pods ovate-lanceolate, with small and scattered warty spines 

 chiefly on the beak. — Near Columbus, Ohio, Sullivant. W. Illinois, Engelmann. 

 July. — Resembles No. 1 in appearance, in the petals, &o. ; the hoods larger, 

 and exceeding the anthers by one half. 



* # Pods not warty-roughened or prickly. 



•*- Leaves all or chiefly opposite, or the middle ones sometimes in flours. 



•*-*■ Stems simple or nearly so (above usually with 2 lines of minute pubescence). 



3. A. phyfolaccoides, Pursh. (Poke-Milkweed.) Stem (3° -5° 

 high) smooth ; leaves broadly ovate, or the upper oval-lanceolate and pointed at both 

 ends, short-petioled, smooth or slightly downy underneath (5' -8' long) ; pedicels 

 loose and nodding, numerous, long and slender (l'-3' long), equalling the pedun- 

 cle, many times longer than the ovate-oblong divisions of the (greenish ) corolla ; hoods 

 of the crown (white) truncate, the margins 2-toothed at the summit, the horn 

 with a long projecting awl-shaped point ; pods minutely downy. — Moist copses ; 

 common. June. 



4. A. pui'jpurasceeas, L. (Purple Milkweed.) Stem rather slen- 

 der (2° -3° high) ; leaves elliptical or ovate-oblong, the lower mucronatc, the upper 

 taper-pointed, minutely velvety-downy underneath, smooth above, contracted at the 

 base into a short petiole ; pedicels shorter than the mostly terminal peduncle, about 

 twice the length of the dark purple lanceolate-ovate divisions of the corolla ; hoods of 

 the crown oblong, abruptly nan-owed above ; the horn broadly scythe-shaped, with 

 a narrow and abruptly inflexed horizontal point; pods smooth. (A. amcena, L., 

 Michx.) — Border of woods, &c, N. England to Michigan and Kentucky : com- 

 mon westward. July. — Flowers as large as in No. I: peduncle and pedicels 

 downy along one side. 



5. A. VSE'icgiitM, L. (Variegated Milkweed.) Nearly smooth 

 (1° -2° high); leaves ovate, oval, or obovate, somewhat wavy, mucronate, con- 

 tracted into short petioles ; pedicels (numerous and crowded) and peduncle short, downy ; 

 divisions of the corolla ovate (white); hoods of the crown orbicular, entire, the 

 horn semilunar with a horizontal point; pods slightly downy. (A. nivea, L., 

 in part. A. hybrida, Michx.) — Dry woods, S. New York to Wisconsin and 

 southward. July. — Remarkable for its very compact umbels of nearly whito 

 flowers, often purple in the centre. Leaves 4-5 pairs, the middle ones some- 

 times whorlcd; veins often purple. Peduncles 1-3, usually ^' long. 



6. A. ©valifolsa, Decaisne in DC. Prodi*. Low (6-15' high), soft- 

 downy, especially the lower side of the ovate or lance-oblong acute slightly peii- 

 oled leaves; umbels loosely 10-lS-fl oioered, either sessile or peduneled; pedice's 

 slender (J'-f' long) ; hoods of the crown oblong, obtuse, yellowish, with a small 

 horn, about the length of the oval greenish white divisions of the corolla (which 

 are tinged with purple outside). (A. lanuginosa, Nutt. ? A. Vaseyi, Carey). — ■ 

 Prairies and Oak-openings, N. Illinois, Vasey, Wisconsin, Lapham, and north- 

 westward. June. — Leaves l-^'-S' long, -|'-1+' wide, smoothish above, the upper 

 sometimes scattered. Flowers about as large as in the next. 



