Family ASCLEPIADACEAs L17 
4, ASCLEPIADACEZ. 
Milkweed Family. 
Erect or decumbent herbs; corona segments terminating in concave 
hoods. 
Corona with an incurved horn in the cavity of each hood. 
1. Asclepias. 
Corona without horns in the hoods. 
Cavity of the hood divided by a crest-like partition; corolla lobes 
spreading. 2. Asclepiodora. 
Cavity of the hood not divided by a crest-like partition; corolla 
lobes refiexed. 3. Acerates. 
Climbing vines; corona of flat bodies terminating in 2-cleft awns. 
4. Gonolobus. 
1. Asclepias. 740. 
Leaves not linear, lanceolate to nearly orbicular. 
Leaves mostly alternate; sap scarcely milky. 1. A. tuberosa. 
Leaves opposite. 
Flowers bright red or purple; leaves lanceolate, acuminate. 
2. A. incarnata. 
Flowers greenish, yellowish, white or merely tinged with purple. 
Leaves narrowed or acute at the apex. 
Glabrous or nearly so; follicles not covered with soft 
processes. 
Corolla segments 10 mm. long or more, hoods longer than 
the incurved horn. 3. A. sullivantii. 
Corolla segments less than 10 mm. long, hoods much 
shorter than the incurved horn. 5. A. amplexicaulis. 
Canescent or tomentose, at least on the lower surface of the 
leaves; follicles covered with soft processes. 
Corolla segments 4-8 mm. long, hoods less than 1 cm. 
long. 6. A. syriaca. 
Corolla segments 8-12 mm. long; hoods 1 cm. or more long. 
7. A. speciosa. 
Leaves not narrowed but truncate or emarginate at the apex. 
Minutely puberulent or glabrous when old. 4. A. latifolia. 
Densely tomentose-canescent all over. 8. A. arenaria. 
Leaves narrowly linear. 
Leaves verticillate; capsule glabrous 5-7 cm. long. 9. A. verticillata. 
Leaves scattered; capsule puberulent 3-5 cm. long. 10. A. pumila. 
1. Asclepias tuberosa L. Butterfly Weed, Pleurisy Root. 
On bluffs and prairies in the eastern part of the state. Crete; Da- 
kota county; Douglas county; Franklin; Lincoln; Wahoo; Wymore. 
2. Asclepias incarnata L. Swamp Milkweed. 
In meadows and swampy places over most of the state. Cherry 
eens: Haigler; Lancaster county; Long Pine; Mullen; Ponca creek; 
imeon. 2 
3. Asclepias sullivantii Engelm. Sullivant’s Milkweed. 
In low prairies and meadows in the southeastern portion of the state. 
Lincoln; Talmage; Weeping Water; Wood River. 
4. Asclepias latifolia (Torr.) Raf. 
In dry places in the southwestern part of the state. Haigler. 
