Tex., Ok\a.- (Waterfall) and N. M. (Guadalupe and Sandoval cos.); May-Sept.; 

 from s. Man. to B.C., Minn, and Tex., w. to the Pac. Coast. 



This species has the most massive flowers of any milkweed. 



2. Asclepias oenotheroides Cham. & Schlecht. Hierba de zizotes. 



Low herbaceous perennial; stems clustered from the thick rootstalk, ascending 

 or decumbent, moderately stout, more or less branched from the base or simple, to 

 45 cm. long, minutely puberulent; leaves opposite, rather long-petiolate, rhombic- 

 ovate to oblong-lanceolate, obtuse to acute at apex, acute to broadly obtuse at 

 base and abruptly cuneate to the petiole, 4-12 cm. long, 1-6 cm. broad, firmly 

 membranaceous, pale-green, minutely puberulent particularly beneath; petioles 1-2 

 cm. long; inflorescences lateral and solitary from few to several of the upper 

 nodes, very shortly pedunculate or subsessile, several-flowered; peduncles 1-2 cm. 

 long or nearly obsolete, minutely puberulent; pedicels rather slender, 15-25 mm. 

 long, minutely puberulent; flowers mediocre; calyx lobes ovate-lanceolate, 3-4 mm. 

 long, minutely puberulent; corolla reflexed-rotate, greenish-white or yellow, the 

 lobes 8-14 mm. long; gynostegium very shortly stipitate, pale-greenish-cream; 

 column broadly obconic, about 1.5 mm. long and 2.5 mm. broad; hoods narrowly 

 obovate-flabellate, 7-10 mm. long, conspicuously narrowed to a narrowly laminate 

 stipe from somewhat above the middle, the tip broadly laminate and minutely 

 arose or repand; horn adnate to near the tip of the hood, the free portion falci- 

 form and incurved, usually accompanied by a smaller posterior appendage; 

 anther head truncate-conic, about 3 mm. long and 4-5 mm. broad; follicles erect 

 on deflexed pedicels, broadly fusiform or ovoid, shortly apiculate, 7-9 cm. long, 

 1.5-2 cm. broad, smooth, minutely pilosulose to glabrate; seeds oval, 6-8 mm. 

 long, the pale-tawny coma 2-2.5 cm. long. A. longicornu Benth., A. Lindheimeri 

 Engelm. & Gray. 



Rocky, chiefly clay soil in llanos, mesas and hills, in dunes, salt marshes, 

 fields and thickets, long roadsides in much of w. half of Tex. and Okla. {Waterfall), 

 flowering throughout the year; also N.M., s. to C.A. 



3. Asclepias purpurascens L. Purple-milkweed. 



Herbaceous perennial; stem rather stout, simple, 4-10 dm. tall, minutely 

 pilosulose when young, becoming glabrate; leaves opposite, petiolate, broadly 

 ovate or oval to ovate- or oblong-lanceolate, obtuse to acute at apex, obtuse 

 to broadly rounded at base and very shortly and abruptly cuneate into the petiole, 

 6-18 cm. long. 3-10 cm. broad, firmly membranaceous, dark-green and glabrate 

 above, paler and densely and generally puberulent below; petioles to 25 mm. long; 

 inflorescences terminal and solitary or paired, several- to rather many-flowered; 

 peduncles rather slender, 1.5-9 cm. long, minutely puberulent; pedicels slender, 

 2-3.5 cm. long, minutely puberulent; flowers rather large and very showy; calyx 

 lobes ovate-lanceolate. 3-4 mm. long, minutely puberulent; corolla deep-rose, 

 reflexed-rotate, the lobes 7-10 mm. long; gynostegium deep-rose, very shortly 

 stipitate; column obconic, 1.5-2 mm. long, 2.5-3 mm. broad; hoods oblong-elliptic, 

 acute to acuminate. 6-7 mm. long; horn about half-adnate, falciform and sharply 

 incurved, much shorter than the hoods; anther head truncately conic, about 2 mm. 

 long and 3 mm. broad; follicles erect on deflexed pedicels, narrowly fusiform, 

 gradually attenuate, 10-16 cm. long, 1-2 cm. thick, smooth, minutely puberulent 

 to glabrate; seeds oval, 5-6 mm. long, the white coma 35-45 mm. long. 



Thickets, swamps, alluvial woodlands and open woods, prairies and fields, 

 spreading to roadsides and railways, in n.e. Tex., Apr.-July; from s. Ont. and 

 N.E. s. to Va. and Tex. 



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