260 NYCTAGINACEAE 



late, pubescent; fruiting involucres fully 1.5 cm. broad, glabrate; lobes triangular; 

 perianth usually white; fruit obovoid, constricted near the base. A. ovata Pursh. 

 0. floribundus Choisy. Dry soil: S.D.— Mo.— Tex.— N.I\I.— Wyo. Plain. 

 Jl-S. 



3. A. polyatricha Standi. Stem sparingly' branched, hirsute below; 

 branches and inflorescence soft-pubescent; leaf-blades glabrous or sparingly 

 pilose, ovate, the uppermost narrowly so, obtuse or rounded at the apex; invo- 

 lucre about 1 cm. wide; lobes broadly ovate, more or less densely pubescent. 

 Canons: Colo. Jl-Au. 



4. A. hirsuta Pursh. Stem strict, 4-8 dm. high, glandular in the panicu- 

 late inflorescence; involucre glandular-pubescent, in fruit 1.5 cm. wide; lobes 

 broadly ovate; perianth purple or pink, jjubescent without. A. aggregata (Or- 

 tega) Speng., a form with axillary involucres. Sandy soil: Sask. — Minn. — 

 Neb. — N.M.^Wyo. Plain — Submont. Je-Au. 



5. A. pilosa (Nutt.) Rydb. Stem erect or decumbent at the base, 3-12 dm. 

 high; leaf-blades lanceolate or oblong, 2-9 cm. long, thick, nearly glabrous; 

 inflorescence cymose, glandular; fruiting involucres 1.2-2 cm. broad; lobes tri- 

 angular-ovate; perianth purplish. Dry sandy soil: Sask. — Wise. — ^La. — -Tex. — 

 Colo. — N.D. Plain — Submont. Jl-Au. 



6. A. Carletoni Standi. Stem about 1 m. high, simple below, soft- 

 pubescent throughout; leaves sessile or nearly so, lanceolate, very thick, acutish, 

 wavy-margined, strongly veined, 7 cm. long, puberulent on both sides; involucres 

 about 15 mm. wide, copiously soft-pubescent, the lobes rounded; fruit 5 mm. 

 long, with 5 prominent smooth ribs. Plains: Kans. — Colo. — Okla. Plain. 

 Je-Jl. 



7. A. glabra (S. Wats.) Kuntze. Stem 6-10 dm. high, erect, branched, 

 glabrous; leaf-blades linear, 6-12 cm. long, thick, glabrous, sessile; inflorescence 

 a large panicle; flowers solitary; fruiting involucre about 1 cm. broad, glabrous; 

 lobes triangular, thin, veiny. Dry soil: s Utah — ^Colo. — N.M. — Ariz.; Chihua- 

 hua. Son. Au-S. 



8. A. sessilifolia Osterh. Stem stout, 5-10 dm. high, erect, branched 

 above, angled; leaves thickish, sessile, 6-8 cm. long, 4 cm. wide; involucre densely 

 hirsute, in fruit 1 cm. broad; perianth purple or pink. Valleys: Colo. Submotit. 

 Jl. 



9. A. bracteata Rydb. Stem 4-12 dm. high, erect or ascending; leaf-blades 

 oblong to linear-lanceolate or linear, 3-9 cm. long, thick; involucres often 

 numerous, in terminal cymes, 10-14 mm. wide; lobes broadly ovate, obtuse; peri- 

 anth white or pale, about 10 mm. broad. Dry and rocky soil: Mo. — Ala. — ■ 

 S.D. Plain. 



10. A. diffusa Heller. Stem 2-3 dm. long; leaves sessile, linear-lanceolate, 

 often narrowly so, 5-6 cm. long, thick; fruiting involucres 7-10 mm. wide; lobes 

 triangular-ovate; perianth rose-colored to white, 6 mm. long; fruit inconspicu- 

 ously ribbed. A. glandulifera A. Nels. A. riscida (Eastw.) CockercU. Gravelly 

 hills and sandy plains: N.D. — Kans. — -N.M. — Ariz. — Wyo. Son. — Plain — 

 Mont. Je-Au. 



11. A. decumbens Nutt. Stem erect or ascending, 4-15 dm. high; leaf- 

 blades 3-10 cm. long, very thick, obtuse or blunt at the apex; involucres 

 numerous, usually in terminal cymes, 1-1.5 cm. wide; lobes rounded-ovate, 

 sometimes acutish; perianth pink, about 10 mm. broad. A. decumheiia was 

 originally described from a form with axillary involucres. A. lanceolata Rydb. 

 represents the ordinary form. Dry sandy soil on plains and prairies: Man. — 

 Tenn.— Tex.— N.M.— Wyo. Plain— Submont. My-S. 



12. A. linearis Pursh. Stem slender, 3-15 dm. high, terete or 4-angled below, 

 erect or ascending; leaf-blades thick, hnear, 2.5-10 cm. long, undulate, sessile, 

 or the lower sometimes short-petioled; perianth finely pubescent, purple. O. 

 angustifolius Sweet. A. montaiiensis Osterh. A. Bodini (Holz.) Alorong., a 

 form with axillary involucres. Dry soil: Minn. — La. — Ariz. — Mont.; Mex. 

 Plain— Mont. Jl-O. 



