Polygonum tenue


Fl. Bor.-Amer. 1: 238. 1803.

Common names: Slender or pleat-leaf knotweed
Synonyms: Polygonum tenue var. protrusum Fernald
Treatment appears in FNA Volume 5. Treatment on page 567. Mentioned on page 562.

Herbs. Stems erect, green or brown-ish, simple or branched from below middle, not wiry, 5–50 cm, glabrous or papillose-scabridulous. Leaves uniformly distributed, articulated to ocreae, basal leaves caducous or persistent, distal leaves abruptly reduced to bracts; ocrea 6–15 mm, glabrous or papillose-scabridulous, proximal part cylindric, distal part soon disintegrating into a few brown fibers; petiole 0.1–1 mm; blade 1-veined, with 1 pleat on each side of midrib, narrowly lanceolate to linear, 25–40 × 1–8 mm, margins usually flat, papillose-denticulate, apex mucronate or cuspidate. Inflorescences axillary and terminal, spikelike, slender, elongate; cymes spaced along branches, 1–2(–3)-flowered. Pedicels enclosed in ocreae, erect, 1–1.5 mm. Flowers closed; perianth 2.5–4.2 mm; tube 15–22% of perianth length; tepals overlapping, green, often brownish when dried, with pink or white margins, petaloid or sepaloid, elliptic, cucullate, navicular, apex rounded; midveins usually unbranched, rarely branched; stamens 8. Achenes enclosed in or slightly exserted from perianth, black, elliptic to oblong, 2.3–4 mm, faces subequal, shiny, smooth or minutely striate-tubercled near edges and apex. 2n = 20.

Phenology: Flowering Jun–Oct.
Habitat: Dry acid soils in exposed sites
Elevation: 100-1000 m


V5 1159-distribution-map.gif

Ont., Ala., Ark., Conn., Del., D.C., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.Dak., Tenn., Tex., Vt., Va., W.Va., Wis., Wyo.


Selected References


Lower Taxa

... more about "Polygonum tenue"
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
Michaux +
Slender or pleat-leaf knotweed +
Ont. +, Ala. +, Ark. +, Conn. +, Del. +, D.C. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Mo. +, Nebr. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio +, Okla. +, Pa. +, R.I. +, S.Dak. +, Tenn. +, Tex. +, Vt. +, Va. +, W.Va. +, Wis. +  and Wyo. +
100-1000 m +
Dry acid soils in exposed sites +
Flowering Jun–Oct. +
Fl. Bor.-Amer. +
Polygonum tenue var. protrusum +
Polygonum tenue +
Polygonum sect. Duravia +
species +