GENUS I. MILKWEED FAMILY. 
1g. Asclepias ovalifolia Dec. Oval-leaved 
or Dwarf Milkweed. Fig. 3401. 
Asclepias ovalifolia Dec. in DC, Prodr, 8: 567. 1844, 
Finely tomentose all over; stem simple, usually 
slender, erect, 10’-2° high. Leaves oval, ovate, 
oblong or ovate-lanceolate, acute or obtuse and 
mucronulate at the apex, rounded or narrowed at 
the base, 2’-3’ long, 3’-14’ wide, short-petioled, 
the upper surfaces becoming glabrate at maturity; 
umbels solitary or few, several-many-flowered; 
peduncles short; corolla greenish-white or pur- 
plish, its segments ovate-oblong, obtuse, 2’-3” 
long; column very short; hoods oval-oblong, yel- 
lowish, nearly twice as long as the anthers, bear- 
ing a large acute tooth on each of the inner mar- 
gins; horn subulate, incurved over the stigma; 
follicles ascending on the reflexed fruiting pedi- 
cels, pubescent. 
In woods and on prairies, Illinois to North Dakota, 
Wisconsin, Manitoba and Athabasca. June-July. 
zo. Asclepias brachystéphana Engelm. 
Short-crowned Milkweed. Fig. 3402. 
Asclepias brachystephana Engelm.; Torr. Bot. Mex. 
Bound. Surv. 163. 1859. 
Puberulent when young, soon glabrate; stems 
‘clustered, often branched, spreading or ascend- 
ing, 6-12’ long. Leaves mostly opposite, lanceo- 
late or linear-lanceolate, thick, long-acuminate at 
the apex, rounded, subcordate or narrowed at the 
base, 2’-5’ long, 2-6” wide, or the lowest shorter ; 
petioles 1-4” long; umbels several, terminal and 
axillary, few-flowered; peduncles short; pedicels 
densely woolly, equalling or longer than the pe- 
duncles; corolla greenish-purple, its segments 
about 2” long; column very short or none; hoods 
ovate, obtuse, shorter than the anthers, the short 
erect-incurved horn slightly exserted; follicles 
erect on the spreading or decurved fruiting pedi- 
cels, downy or hoary, acuminate, 2’—33’ long. 
In dry soil, Kansas (according to B. B. Smyth), 
Wyoming to Texas, Arizona and Mexico. June-Aug. 
a1. Asclepias perénnis Walt. Thin-leaved yf 
Milkweed. Fig. 3403. 
uy Vy 
Asclepias perennis Walt. Fl. Car. 107. 1788. i 
iN 
NY) 
iis 
Puberulent above, glabrous below; stem slen- 
der, simple or branched, erect, 1°-3° high. Leaves 
thin, opposite, lanceolate, oblong or ovate-lanceo- 
late, slender-petioled, acuminate or acute at both 
ends, 2’-6’ long, #’/-1’ wide, nearly glabrous; um- 
bels solitary or several and corymbose; peduncles 
1-2’ long; pedicels slender, 3’-1’ long; flowers 
small, white; corolla-segments oblong, 1-2” 
long; column about 4” high; hoods oval, erect, 
entire, about as long as the anthers, shorter than 
the subulate-filiform incurved horn; follicles gla- 
brous, erect on the nearly erect fruiting pedicels ; 
seeds 5’-6” long, 33-43” wide, thin, usually with- 
out coma. 
On river-shores and in wet places, North Carolina 
to Indiana, Illinois and Missouri, south to Florida 
and Texas. May-—Aug. 
