234 POLYGONACEAE 



clusters; perianth 3 mm. long; achenes darlc brown, granular and dull. Waste 

 places: Me.— Ga.— Ark.— N.M.— Alta.; (? Ida.) Plain. Je-S. 



buxiforme Small. Annual 



dm. long; leaves oblong, elliptic or oblanceolate, 0.5-2.5 cm. long, usually ob- 

 tuse, often crisp on the margin; perianth 2-2.5 mm. long; achenes 2-2.5 mm. 

 long, dark brown, mostly dull, granular. Sandy or alkaline soil: Ont.— Va.— 

 Tex.— Nev.— B.C. Plain— Mont. Je-S. 



4. P. aviculare L. Annual or sometimes perennial; leaves oblong-lanceolate, 

 acute at both ends, petioled, dull bluish green, rather thin, 1-3 cm. long; flowers 

 pedicelled ; perianth 2.5-3.5 mm. long; achenes dark, rugulose-striate, dull. Waste 

 places: Newf.— Va.— Calif.— B.C.; nat. or adv. from Eu. Plain— Submont . My-0. 



6. P. neglectum Besser. Annual or perennial; stems with short intemodes, 

 strongly striate, usually minutely roughened; leaves firm, narrowly elliptic- 

 lanceolate, or the upper rarely hnear; margins often revolute when dry; perianth 

 2-2.5 mm. long, venose; segments with usually purplish margins; achenes reddish 

 brown apiculate-acummate. P. aviculare angustissimum Meisn. Waste places: 

 Me.— -Fla.— Ark.— N.M.— Alta.; nat. or adv. from Eu.; more common than 

 P. aviculare. Plain— Submont. Je-N. 



6. P. ramosissimum Michx. Annual; stem 2-10 dm. high, somewhat 

 virgate, yellowish green; leaves lanceolate, oblong, or linear-oblong, 1-4 cm. long, 

 yellowish green, the upper ones much reduced in size; perianth about 3 mm. long; 

 achenes 3 mm long, black, not shining. River valleys and sandy soil: Man.— 

 lUs.—N.M.— Nev.— Wash.— B.C. Plain— Mont. Jl-S. 



u ^'iF'.2 prolificum (Small) B. L. Robins. Annual; stem 3-5 dm. high, much 

 branched, strongly striate, dark green or reddish; leaves linear-oblong or linear, 

 tnick, obtuse or acute, strongly veined beneath, dark green, 1-2 cm. long; peri- 

 anth about 2 mm. long; achenes brown, 2 mm. long, concave on the lanceolate- 

 deltoid faces shining. (?) P. flexile Greene. Sandy places: Me.— Va.— Colo. 

 — Mont. Plain. Jl-0. 



u ^'iF'j f^J'^scens Small. Annual or perennial; stem erect, ultimately 

 branched, 1-5 dm high; leaves thick, narrowly oblong or elliptic, 1-2.5 cm. long, 

 the upper reduced; perianth 3 mm. long; achenes 2-2.5 mm. long, dull. Sandy 

 soil: Sask.— Colo.— Nev.— Ida. Plain— Submont. Je-S. 



r, 9- P- sawatchense Small. Annual; stems erect, striate, obscurely 4-angled, 

 branched from the base, 5-30 cm. high; lower leaves oblanceolate, 1-2 cm. long, 

 acute or obtuse at the apex, often more or less revolute, with a prominent mid- 

 vem; perianth-segments green, only sUghtly lighter on the margins, 2 mm. long; 

 achenes rather blunt at both ends, smooth and glossy. Hillsides and mountains : 

 b.D.— N.M.— Cahf.— Wash. Submont .—M ont . Jl-Au. 



u ^\ ?• ,W**f°]iii Small. Annual; stem erect, 5-15 cm. high, sparingly 

 branched, 4-angled, glabrous; leaves linear. 1-5 cm. long; bracts reduced, 0.5-1 

 cm. long, hnear-lanceolate ; perianth-segments green, pinkish on the margins, 2 

 mm long; achenes nearly black, narrowly ovoid, strongly striate. P. imhricatum 

 rsutt., not Kaf P. confertifiorum Nutt. . Wet places: B.C.— Sask.— N.M.— 

 L-alif. Plain — Mont. Je-Au. 



11. P. xinifolium Small. Annual, dwarf; stem 1-3 cm. high, simple, or 

 nearly so; weU developed leaf mostly solitary, linear, erect, 7-10 mm. long; bracts 

 several, crowded, imbricate, linear or hnear-lanceolate; perianth-segments about 

 l.o mm. long white or pinkish, with green ribs; achenes about 1.3 mm. long, 

 shming, mcluded. Wet places: Mont.— Colo.— Utah. Plain— Mont. Jl-Au. 



*v, ■'?' P- Pfjojiycliioides Small. Annual, bushy; stem copiously branched at 



segments 



becoming fully 2 mm. long; lobes slightly keeled, acutish; achenes rhombic, 

 about 2 mm. long, granular. Wet places: Mont.— Wyo. Submont. Au. 



*v ^1?* P- ^®llo?firii Greene. Annual; stem erect, 3-8 cm. high, branched at 

 the base; leaves linear, acute, 5-10 cm. long, spreading; perianth-segments 1.5-2 



