renouée de Fowler

Polygonum allocarpum S. F. Blake

Plants rarely purple tinged, homophyllous or heterophyllous, subsucculent. Stems prostrate to ascending, 15-50 cm. Leaves: ocrea 4-12 mm; petiole 5-7 mm; blade green, rarely purple tinged, elliptic to elliptic-obovate, 20-35(-50) × 10-15(-25) mm, apex acute or obtuse; middle stem leaves 1.1-2.1(-3.4) times as long as adjacent branch leaves. Cymes 1-5-flowered. Pedicels 1-2.5 mm. Perianths 3-4.5 mm. Achenes broadly ovate, 3-gonous, (2.5-)3-3.7(-4.5) mm, faces subequal, concave, roughened, rarely obscurely tubercled. 2n = 40, 60.

Flowering Jul-Oct. Sandy, gravelly seashores; 0-30 m; St. Pierre and Miquelon; B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Yukon; Alaska, Calif., Maine, Oreg., Wash.