elliptic to linear-lanceolate, acute to acuminate at apex, obtuse to somewhat 

 cordate at base. 5-15 cm. long, to 4 cm. broad, membranaceous; petioles to 1 cm. 

 long; inflorescences usually paired at the upper nodes, solitary below, several- to 

 many-flowered; peduncles 1.5-7 cm. long; pedicels 1-1.5 cm. long; flowers rather 

 small; calyx lobes linear-oblong, 1-1.5 mm. long, pilosulose; corolla bright-pink 

 or rarely white, reflexed-rotate. the lobes 3-4 mm. long; gynostegium paler pink 

 or rarely white; column cylindric. 1-1.5 mm. long, about 1 mm. wide; hoods 

 cucullate. rounded at the tip, about 1.5 mm. long; internal horn narrowly acicular, 

 slightly incurved over the stigma head, somewhat longer than the hood; anther 

 head about 1.5 mm. long; follicles erect on erect pedicels, fusiform, long-attenuate, 

 7-9 cm. long, to 12 mm. thick, smooth, glabrous to generally pilosulose; seeds 

 broadly oval, 7-10 mm. long, the white coma about 2 cm. long. 



In moist or wet soil about water-bodies and in marshes, water of lakes and 

 along and in sluggish or clear-flowing streams from the Plains Country to s.-cen. 

 Tex., Okla. (widespread) and N. M. (Chaves, Colfax, Lincoln and Otero cos.), 

 June-Oct.; from e. Can., s. to Fla. and w. to Ut. and N. M. 



The following two phases of this species are found sympatrically. Muskrats are 

 known to eat the rootstocks. 



1. Plant scatteringly and inconspicuously pubescent to essentially glabrous; stems 

 usually repeatedly branching; leaves usually rather narrowly oblong- 

 to linear-lanceolate, the apex gradually acuminate, the base obtuse 



to truncate, rather long-petiolate 



var. incarnata (var. longifolia Gray). 



I. Plant generally and conspicuously pubescent; stems simple or branching infre- 



quently; leaves ovate- to broadly oblong-elliptic, the apex acute to 

 abruptly acuminate, the base rounded to somewhat cordate, infre- 

 quently broadly obtuse, rather short-petiolate 



var. pulchra (Ehrh.) Fern. 



10. Asdepias texana Heller. 



Herbaceous perennial, becoming somewhat shrubby at the base after several 

 years; stems slender, to 5 dm. tall, usually branching, inconspicuously pilosulose 

 in decurrent lines from the nodes; leaves opposite, petiolate, broadly oval to 

 narrowly oblong-elliptic, obtuse to acuminate at apex, obtuse or rarely attenuate 

 at the base, 2-7 cm. long, to 35 mm. broad, thinly membranaceous, finely puberu- 

 lent upon the midrib and veins beneath; petioles to 1 cm. long, minutely pilosulose; 

 inflorescences solitary at the uppermost nodes, several- to many-flowered; pedun- 

 cles slender, 1-2 cm. long; pedicels 1-1.3 cm. long, finely puberulent; flowers 

 small; calyx lobes narrowly lanceolate, 1.5-2 mm. long, minutely puberulent; 

 corolla reflexed-rotate, white, the lobes about 3 mm. long and widely spreading; 

 gynostegium long-stipitate, white; column cylindric, about 1.5 mm. long and 1.7 

 mm. wide at the base; hoods cucullate, about 2 mm. long, rounded at the tip; 

 horn basal, narrowly acicular, nearly twice as long as the hood, slightly incurved 

 over the anther head; anther head about 2.5 mm. long; follicles erect on erect 

 pedicels, narrowly fusiform, 9-12 cm. long, smooth, glabrous; seeds broadly oval, 

 about 8 mm. long, the white coma about 2 cm. long. 



Canyons, arroyos, rocky hills and edge of water along streams in the Edwards 

 Plateau and Trans-Pecos of Tex., May-Aug.; also n. Mex. 



II. Asclepias perennis Walt. Fig. 637. 



Herbaceous perennial from rather short and superficial rootstalks; stems slender, 

 3-5 dm. tall, usually branching only from the base, very inconspicuously pilosulose 

 in decurrent lines from the nodes or essentially glabrous; leaves opposite, 

 elliptic-lanceolate to narrowly oblong or broadly oval to ovate-elliptic, acuminate 

 at apex, attenuate at the base, 5-14 cm. long, to 15 mm. broad, thinly mem- 



1347 



