232 POLYGONACEAE 



not crisp; flowers perfect; perianth greenish, 3 mm. long; inner lobes in fruit 

 deltoid or deltoid-cordate, 5-8 cm. long, acute or short-acmninate. Swampy 

 grounds in the mountains: Colo. — Utah. Subtnont. — Mont. Jl-Au. 



13. R. Patientia L. Stem erect, grooved, 5-15 dm. high; blades of basal 

 leaves ovate-lanceolate, 1-4 dm. long; pedicels jointed below the middle; flowers 

 perfect; perianth green, 4-5 mm. long; inner lobes in fruit 6-7 mm. long, rounded- 

 cordate, sinuate on the margins; achenes 3 mm. long. R. Briliannica of western 

 reports, not L. Patience. Waste places: Newf. — N.J. — Utah; cultivated 

 and occasionally escaped; native of Eu. Plain — Submont. Je-Jl. 



14. R. altissimum Wood. Stem grooved, 5-12 dm. high; blades of the 

 basal leaves lanceolate or oblong-lanceolate, 5-25 cm. long, acute at both ends, 

 papillose; flowers perfect; pedicels jointed near the base; perianth Ught green, 2 

 mm. long; inner lobes in fruit triangular-cordate, 4-5 mm. long, reticulate, entire- 

 margined. Along streams: Mass. — Md. — N.M. — -N.D. Plain. Ajj-Je. 



15. R. crispus L. Stem 3-10 dm. high, erect, simple; blades of the basal 

 leaves oblong to linear-lanceolate, 1.5-3 dm. long, cordate, rounded, obtuse or 

 acute at the base, more or less papillose; flowers perfect; pedicels jointed at the 

 base; perianth dark green; inner lobes in fruit 3-5 mm. long. Curled Dock. 

 Waste places: Newf. — -Fla. — Calif. — B.C. Plain. Je-Au. 



16. R. mexicanus Meisn. Stem 3-6 dm. high; blades of the basal leaves 

 lanceolate or hnear-lanceolate, pale, 5-15 cm. long, 1-2.5 cm. wide; flowers 

 perfect; perianth pale green, 2-3 mm. long; inner lobes in fruit 5-6 mm. long, 

 truncate at the base. /?. saZia/oZiws Am. auth., not Weinm. Along rivers: Lab. 

 — Me.— Mo.— N.M.— B.C.; Mex. Plain—Mont. My-Au. 



17. R. obtusifolius L. Perennial, with a taproot; stem stout, 5-12 dm. 

 high, grooved; blades of the basal leaves broadly ovate, 1.5-3 dm. long; pedicels 

 jointed below the middle; perianth greenish or purplish, 3 mm. long; inner lobes 

 in fruit about 5 mm. long, hastate or deltoid, strongly reticulate. Waste places: 

 N.S.— Fla.— N.M.— Ore.— B.C.; nat. from Eu. Plain— Son. Ap-Au. 



18. R. maritimus L. Annual; stem 3-10 dm. high, leafy; leaf-blades 

 lanceolate or linear-lanceolate, 3-25 cm. long, undulate and crisp; pedicels 

 jointed at the base; perianth greenish, 1-1.5 mm. long; inner lobes in fruit about 

 2 mm. long, with 1-3 bristle-like teeth on the margins. R. persicarioides Am. 

 auth., not L. Golden Dock. Sandy shores: N.B. — -N.C. — 'CaUf. — B.C. 

 Plain — Submont. Jl-S. 



8. OXYRIA Hill. Mountain Sorrel. 



Low perennials, with acid juice and thick fleshy taproots. Leaves alternate, 

 but mostly basal. Flowers perfect, in verticils, arranged in panicled racemes. 

 Sepals 4; the outer larger than the inner; stamens 6; filaments short-subulate. 

 Ovary 1-celled; ovules solitary; styles 2, short; stigmas fimbriate. Achenes 

 thin, lenticular, nearly flat, broadly winged. 



1. O. digyna (L.) Hill. Stem scapiform, 5-30 cm. high; blades of the basal 

 leaves reniform or rounded-reniform, 1-3 cm. in diameter, sometimes emarginate 

 at the apex; panicle narrow, racemiform; perianth red or green, 1.5-2 mm. long, 

 the inner in fruit erect, reniform-orbicular, 4-6 mm. broad; achenes in fruit 

 broadly winged. Arctic-alpine regions among rocks: Greenl. — 'N.H. — -Alta. — 

 N.M.— Calif.— Alaska; Eurasia. Alp.— Mont. Jl-S. 



9. POLYGONUM (Tourn.) L. Knotweed, Doorweed, Knotgrass. 



Perennial or annual, sometimes somewhat shrubby herbs, with alternate 

 leaves and somewhat fleshy or leathery leaf-blades articulate to the ocreae. 

 Ocreae at first 2-lobed, soon lacerate, hyaline. Inflorescence of axillary small 

 clusters. Calyx of 5 or rarely 6, partially united sepals, mostly green with 

 white, pink, or yellowish margins. Stamens 3-8, usually 5 or 6; filaments, at 

 least the inner ones, dilated. Ovary 1-celled, 1-ovuled; styles 3, usually dis- 

 tinct. Achenes 3-angled, brown or black; endosperm horny; cotyledons incum- 

 bent. 



