BUCKWHEAT FAMILY 235 



mm. long, greenish, with white or cream-colored margins; achenes 1.5 mm. long, 

 rhombic-ovoid, light brown, granular, somewhat striate, dull. In wet soil: 

 Wash. Mont. 'Colo. 'Calif. Submont. Mont. Jl-S. 



14. P. polygaloides Meisn. Annual, glabrous; stem slender, erect, 1-2 dm. 

 high, with ascending branches; leaves narrowly linear, 1-3 cm. long, strict; floral 

 leaves oblong or elliptic; perianth-segments 2 mm. long, white or pinkish, with 

 dark midribs; outer segment longer than the inner; achenes about 1.5 mm. long. 

 Wet places: Wash. Mont. Wyo. Ore. Submont. Je-Au. 



15. P. Engelmannii Greene. Annual; stem often diffusely branched at 

 the base, 0.5-3 dm. high; lower leaves linear-oblanceolate, 0.5-2 cm. long, the 

 upper reduced, bract- like, subulate; perianth-segments oblong, obtuse, with 

 whitish margins; achenes 2-2.5 mm. long, ovoid, black, smooth and shining. P. 

 tenue* microspermum Engelm. Hillsides and mountains: B.C. Mont. Colo. 

 Plain Mont. Jl-S. 



16. P. Douglasii Greene. Annual; stem erect, 2-4 dm. high, with ascend- 

 ing branches; lower leaves oblanceolate, 2-5 cm. long, mostly obtuse or acutish; 

 the upper linear and reduced, scattered; perianth-segments white or rose-colored 

 on the margins; achenes 3-4 mm. long, black, smooth and shining. P. consimile 

 Greene. (?) P. emaciatum A. Nels. P. pannosum S. S. Sharp. Hillsides and 

 in sandy soil: Vt. N.Y. N.M. Calif. B.C.; probably only introduced 

 east of the Rockies. Plain Mont. Je-Au. 



17. P. majus (Meisn.) Piper. Annual; stem wiry, terete, 2-4 dm. high, 

 with ascending branches; leaves 2-6 cm. long; bracts linear-subulate, remote; 

 perianth 4-5 mm. long; segments white, with green midrib; achenes black, shin- 

 ing, smooth, 3-3.5 mm. long. P. coarctatum majus Meisn. Stony soil: Wash. 

 Mont. Wyo. Ore. Plain Submont. Je-S. 



18. P. spergulariaeforme Meisn. Annual, scurfy throughout; stem erect, 

 1-3 dm. high, branched from the base; leaves 1-3 cm. long, usually somewhat 

 revolute; bracts rather crowded, subulate; perianth 3.5-4 mm. long, pink; 

 achenes about 3.5 mm. long, black, smooth and shining except the granular apex 

 and angles. P. coarctatum Dougl., not Willd. Ridges: B.C. w Wyo. Calif. 

 Plain Submont. Jl-Au. 



19. P. montanum (Small) Greene. Annual; stem branched from the base, 

 1-3 dm. high, floriferous from near the base; low r er leaves elliptic or oblong- 

 oblanceolate, 1-3 cm. long, 1-nerved; upper leaves smaller, lanceolate or oblong; 

 perianth-segments oblong, dark green or purplish, with white or pinkish margins; 

 achenes black, shining, striate. Mountains: Alta. N.M. Calif. Submont. 

 Subalp. Jl-Au. 



20. P. commixtum Greene. Annual; stem 0.5-1.5 dm. high, glabrous, 

 branched from the base, glabrous; leaves oval, oblanceolate, or lanceolate, abruptly 

 cuspidate-mucronate, 1-2.5 cm. long, 1-nerved, glabrous; perianth about 3 mm. 

 long; segments elliptic, green, with yellowish white or purplish margins; achenes 

 almost black, smooth and shining. Mountains: Colo. Mont. Submont. 

 Subalp. Jl-Au. 



21. P. Austinae Greene. Annual; stem mostly erect, 0.5-1 dm. high, 

 branched from the base; leaves ovate-lanceolate to oblanceolate, 0.5-1.5 cm. 

 long, the upper much reduced; perianth green, 2.5 mm. long, drooping; segments 

 narrowly oblong, obtuse, dark green, with white margins; achenes 2.5-3 mm. 

 long, black, smooth and shining. Sandy places: Alta. Wyo. Calif. Sub- 

 mont. Au-S. 



10. PERSICARIA (C. Bauhin) Mill. SMARTWEED, LADY'S THUMB, 



WATER PEPPER. 



Perennial or annual, caulescent herbs, not twining, with alternate leaves and 

 entire leaf-blades, continuous with the ocreae. The latter cylindric, mostly mem- 

 branous, truncate. Racemes spike-like; pedicels articulate below the calyx. 

 Calyx more or less colored, white or greenish, glandular-punctate; perianth-seg- 

 ments mostly 5. Stamens 4-8, filaments not dilated. Ovary 1-celled, 1-ovuled; 



