acicular, somewhat longer than the hoods, gradually arching over the anther head; 

 anther head cylindric. about 1.5 mm. long and broad: follicles erect on erect pedi- 

 cels, narrowly fusiform, 5-9 cm. long and 6-8 mm. thick, smooth, glabrous or in- 

 conspicuously pilosulose; seeds broadly oval, 7-8 mm. long, the white coma about 

 2 cm. long. A. galioides of Am. auth. 



Sandy and rocky plains and flats, marshes, seepage along streams and about 

 springs, and along irrigation ditches, in the w. half of Tex., especially in the 

 Trans-Pecos, Okla. (Alfalfa Co.). N.M. (DeBaca. Dona Ana. Colfax and Taos 

 COS.) and Ariz. (Cochise Co.), May-Sept.; from Tex., w. to Ut., Colo., Ariz, and 

 n. Mex. 



This plant is known to be very poisonous to livestock. 



7. Asclepias longifolia Michx. 



Herbaceous perennial from a stout rather tuberous rootstalk; stems rather 

 slender, simple. 2-7 dm. tall, minutely pilosulose; leaves irregularly approximate, 

 sessile or subsessile. linear-lanceolate, gradually acuminate at apex, attenuate at 

 base, 6-18 cm. long, 2-10 mm. broad, minutely pilosulose to glabrate; inflores- 

 cences terminal and solitary and lateral from few of the uppermost nodes, 

 several- to many-flowered, rather lax and hemispherical, pedunculate; peduncles 

 slender, 2-6 cm. long, rarely obsolete, minutely pilosulose; pedicels very slender, 

 1.5-2 cm. long, minutely pilosulose; corolla reflexed-rotate, pale-greenish-white, 

 liberally tinted with purple (particularly without), the lobes about 5 mm. long; 

 gynostegium shortly but definitely stipitate, greenish-white tinted with purple 

 below; column about 1.5 mm. long and 1 mm. broad; hoods deeply saccate, obo- 

 void, about 2 mm. long, without a horn, much lower than the anther head; anther 

 head about 1.5 mm. long and broad; follicles erect on deflexed pedicels, narrowly 

 fusiform, long-attenuate, minutely pilosulose, 8-12 cm. long, about 1 cm. thick; 

 seeds rather broadly oval, about 1 cm. long, the white coma about 35 mm. long. 



Flatwoods, swamps, wet savannahs, wet depressions and low pinelands in e. 

 Tex. and s.e. Okla. (LeFlore Co.), Apr.-Oct.; from Del. to Fla. and w. to Tex. 



8. Asclepias curassavica L. Veintiunilla. 



Herbaceous annual; stems 3-12 dm. tall, frequently rather woody toward the 

 base, simple or branched, minutely arachnoid-tomentulose when young, soon 

 glabrate; leaves opposite, petiolate, elliptic-lanceolate, acute to acuminate at apex, 

 acute to obtuse at base. 5-12 cm. long, 1-3 cm. broad, minutely pilosulose when 

 very young, soon glabrate, thinly membranaceous; petioles to 1 cm. long; inflores- 

 cences solitary at the upper nodes, several- to many-flowered; peduncles 3-6 cm. 

 long; pedicels 1-2 cm. long; flowers rather large and showy, calyx lobes narrowly 

 lanceolate. 2-3 mm. long; corolla reflexed-rotate, bright-crimson, rarely yellow or 

 white, the lobes 5-10 mm. long; gynostegium long-stipitate. deep-yellow; column 

 cylindric or conic. 2-3 mm. long and 1 mm. broad at the base; hoods cucuUate, 

 distinctly stipitate, broadly oblong, rounded at the tip. 3-5 mm. long; horn basal, 

 narrowly acicular. 4-5 mm. long, slightly incurved over the anther head; anther 

 head cylindrical, 2-3 mm. long, 1.5-2.5 mm. broad; follicles erect on erect 

 pedicels, narrowly fusiform. 6-10 cm. long, smooth, glabrous; seeds broadly oval, 

 5-7 mm. long, the white coma 2-3 cm. long. 



In moist or wet soil in s. Tex., Apr. -Aug.; an almost ubiquitous waif of the 

 trop. and subtrop. of Am., also widely introd. in the trop. of the Old World. 



9. Asclepias incamata L. Swamp-milkweed. Fig. 636. 



Herbaceous perennial from rather short and superficial rootstalks; stems 

 usually fairly stout. 4-15 dm. tall, simple to copiously branched; leaves opposite 

 or very rarely certain nodes condensed to form a false whorl, petiolate, ovate- 



1345 



