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rowly lanceolate: spikes (terminal compound) erect, narrow, andrather leafy : bracts 
solitary, subulate, rigid, attenuate into a pungent awn, exceeding the oblong-spatu- 
late obtuse or emarginate sepals.—On the Lower Rio Grande, near the mouth. 
+ + Flowers crowded in close and small axillary clusters: stems low, spreading or ascend- 
ing: sepals and stamens 3, or the latter only 2. 
6. A. albus L. Smooth, pale greea: stems whitish, erect or ascending, diffusely 
branched: leaves small, obovate and spatulate-obong, very obtuse or retuse: flowers 
greenish: sepals acuminate, half as long as the rugose fruit, much shorter than the 
subulate rigid pungently pointed bracts: seed small, 1 mm. broad.—Central Texas 
and northward, the most common prairie tumbleweed. 
7, A. blitoides Watson. Like the last, but prostrate or decumbent: spikelets usu- 
ally contracted: bracts ovate-oblong, short-acuminate: sepals obtuse or acute: fruit 
not rugose: seed about 2 min. broad.-—From the valleys and plains of northern Texas 
to Gillespie County. . 
8. A. Blitum L. Resembling the last, but usually erect, with shorter and more 
scarious bracts, and a smaller seed more notched at the hilum.—Low places near 
Camp Bache. July. 
** Utricle bursting or imperfectly circumscissile: flowers monecious: leaves with spiny 
axils, 
9, A. spinosus L. (THORNY AMARANTH.) Smooth, bushy-branched: stem red- 
dish: leaves rhombic-ovate or ovate-lanceolate, dull green, a pair of spines in the 
axils: upper clusters sterile, forming long slender spikes; the fertile globular and 
mostiy in the axils: flowers yellowish-green.—From Tom Greene County to Laredo. 
** © Utricle circumscissile or indehiscent: flowers monwcious or diecious: sepals (5) of the 
fertile lowers more or less dilated above and spreading, deciduous with the fruit: no spines 
in the axils. 
+ Fruit circumscissile, 
++ Flowers monacious and diwcious. 
10. A. Torreyi Benth. Leaves ovate-oblong or ovate-lanceolate: glomerules pani- 
culate spiked and axillary: bracts and the sepals of the staminate flowers cuspidate- 
acuminate; scpals of the pistillate flowers united below, obovate-spatulate, rounded 
above and entire or retuse or emarginate.—Colorado to western Texas and south- 
ward. 
++ ++ Flowers monecious: stems ercet, slender: glabrous. 
11. A. Pringlei Watson. Stems 3dm. high or more: leaves linear-oblanceolate, 2.5 
to 5 cm. long: inflorescence leafy: bracts lanceolate, spinulose-acuminate, equaling 
the fruiting calyx: staminate flowers few, mingled with the pistillate ones, with 
narrow acute sepals; sepals of the pistillate flowers distinct, green with a broad 
scarious margin, obovate, obtuse or retuse, and somewhat denticulate, the broad 
claw becoming gibbously thickened in fruit: fruit cireumscissile near the base.— 
Rocky hills of Limpia Cation. 
12. A. fimbriatus (‘Torr.) Benth. Stems 3to 9dm. high: leaves linear, 3 to 6 dm. 
long, attenuate into a slender petiole, obscurely nerved: flowers reddish, in rather 
loose clusters, scattered or approximate in a long terminal spike which is leafy below: 
bracts shorter than the calyx, narrow, acute: sepals of sterile flowers obtuse, 
oblong; of fertile flowers broadly fan-shaped, 2to3 mm. long, with a narrow thick- 
ened strongly nerved base, slightly united, the upper margin fimbriately incised. 
(Sarratia Berlandieri, var. fimbriata Torr.)—From the Chisos Mountains to San Diego. 
++ ++ ++ Flowers diecious: stout, pubescent or glabrate. 
13. A. Palmeri Watson. Stems erect, 6to9dm. high, branching: leaves oblong- 
rhomboid, equaling the petiole, the upper lanceolate ; flowers in close elongated linear 
