Polygonum aviculare subsp. buxiforme

(Small) Costea & Tardif

Sida 20: 988. 2003.

Common names: American knotweed renouée faux-buis
WeedyEndemic
Basionym: Polygonum buxiforme Small Bull. Torrey Bot. Club 33: 56. 1906
Treatment appears in FNA Volume 5. Treatment on page 558. Mentioned on page 557.

Plants gray-green or bluish green, rarely green, homophyllous or subheterophyllous. Stems 1–3, erect to ascending, ± unbranched, 5–15 cm, or numerous, procumbent, mat-forming, extensively branched, 20–70 (–200) cm. Leaves: ocrea 3.5–6.5 (–8) mm, proximal part cylindric, distal part silvery, relatively persistent, with inconspicuous veins, leaving almost no fibrous remains after disintegrating; petiole 0.3–2 (–3.5) mm; blade green or gray-green, lateral-veins visible but not raised abaxially, lanceolate to elliptic, oblanceolate, or obovate, 6–30 (–45) × 3–6 (–13) mm, 2.5–5.6 (–10) times as long as wide, apex acute to obtuse; stem-leaves 1–2.5 times as long as branch leaves. Cymes mostly uniformly distributed, but also aggregated at tips of stems and branches, 2–6-flowered. Pedicels mostly enclosed in ocreae, 1–2.5 mm. Flowers: perianth (2–) 2.3–3.4 (–3.6) mm, 0.9–1.3 (–1.5) times as long as wide; tube 20–36% of perianth length; tepals overlapping, green with white or sometimes pink margins, oblong, apex cucullate, outer tepals pouched at base; veins branched, moderately to strongly thickened; stamens 7–8. Achenes usually enclosed in perianth, light-brown to brown, ovate, 3-gonous, (1.8–) 2–2.8 (–3) mm, faces subequal, concave to flat, apex straight, coarsely striate-tubercled to obscurely tubercled; late-season achenes common, 2.5–5 mm. 2n = 60.


Phenology: Flowering Jul–Nov.
Habitat: Roadsides, vacant lots, sidewalks, packed and nondrifting sands, borders of marshes and dunes
Elevation: 0-3500 m

Distribution

V5 1139-distribution-map.gif

Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Ont., Que., Sask., Yukon, Ala., Alaska, Ariz., Ark., Calif., Colo., Conn., Del., D.C., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.

Discussion

Although apparently it has a North American origin, subsp. buxiforme is considered part of the Polygonum aviculare complex because it intergrades with subsp. aviculare (M. Costea and F. J. Tardif 2003).

Selected References

None.

Lower Taxa

None.

"/2" is not declared as a valid unit of measurement for this property.

0.28 cm2.8 mm <br />0.0028 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
light-brown;brown +
exserted +  and included +
dull +  and shiny +
smooth;roughened +
3-gonous +  and ovate +
whitish yellow +
elliptic +  and oblong +
coarsely striate-tubercled +  and obscurely tubercled +
straight +
cucullate;acute;obtuse +
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
(Small) Costea & Tardif +
not stipelike +
Polygonum buxiforme +
5 cm50 mm <br />0.05 m <br /> (6 cm60 mm <br />0.06 m <br />) +
gray-green +  and green +
0.6 cm6 mm <br />0.006 m <br /> (5 cm50 mm <br />0.05 m <br />) +
spatulate;obovate;spatulate;obovate;elliptic;lanceolate;elliptic +
coriaceous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
foliaceous +  and perfoliate +
scale-like +
just below the soil surface or and above the soil surface +  and spreading +
American knotweed +  and renouée faux-buis +
2-6-flowered +
aggregated +  and distributed +
Alta. +, B.C. +, Man. +, N.B. +, Nfld. and Labr. +, N.W.T. +, N.S. +, Ont. +, Que. +, Sask. +, Yukon +, Ala. +, Alaska +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, Del. +, D.C. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Mich. +, Minn. +, Miss. +, Mo. +, Mont. +, Nebr. +, Nev. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, N.C. +, N.Dak. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Utah +, Vt. +, Va. +, Wash. +, W.Va. +, Wis. +  and Wyo. +
tubercled +  and striate-tubercled +
concave +
0-3500 m +
concave +  and flat +
subequal +
persistent +
adnate +, free +  and distinct +
disarticulating +  and solid +
decumbent to erect +  and prostrate +
unwinged +  and winged +
black +, red +, brown +  and yellowish +
exserted +  and included +
pubescent +  and glabrous +
spheroidal +, 4-gonous +, lenticular +, biconvex +, discoid +, 3-gonous +  and 2-gonous +
Roadsides, vacant lots, sidewalks, packed and nondrifting sands, borders of marshes and dunes +
compound +, branched +  and simple +
nonmembranous +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
sessile +  and petiolate +
deciduous +
pink +  and white +
pubescent +  and glabrous +
lobed +, undulate +, crisped +, crenulate +  and entire +
unbranched +  and branched +
not +  and thickened +
swollen +
0.65 cm6.5 mm <br />0.0065 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
silvery +, white +  and hyaline +
disintegrating +
deciduous +  and persistent +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
coriaceous +  and membranous +
somewhat larger +
anatropous +, , +  and orthotropous +
erect;spreading +
accrescent +
0.1 cm1 mm <br />0.001 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
spreading;erect +
0.34 cm3.4 mm <br />0.0034 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
greenish white;pink +
0.9-1.3(-1.5) +
campanulate +  and urceolate +
nonaccrescent +
0.23 cm2.3 mm <br />0.0023 m <br /> (0.34 cm3.4 mm <br />0.0034 m <br />) +
fleshy +, indurate +  and membranous +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Flowering Jul–Nov. +
(2-)3(-4)-carpellate +
slender;stout +
woody +  and fibrous +
Weedy +  and Endemic +
7 +  and 8 +
1-2.5 times as long as branch leaves +
branched +  and unbranched +
70 cm700 mm <br />0.7 m <br /> (200 cm2,000 mm <br />2 m <br />) +
flexuous +
mat-forming +  and procumbent +
erect +  and ascending +
numerous +, 1 +  and 3 +
papillous-scabridulous +
20 cm200 mm <br />0.2 m <br /> (70 cm700 mm <br />0.7 m <br />) +
2 +  and 3 +
penicillate +, fimbriate +  and capitate +
deciduous +  and persistent +
2-lobed +  and cylindric +
coriaceous +  and membranous +
connate +  and distinct +
spreading;erect +
Polygonum aviculare subsp. buxiforme +
Polygonum aviculare +
subspecies +
overlapping +
connate +  and distinct +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
inconspicuous +
subheterophyllous +  and homophyllous +
green +, bluish green +  and gray-green +
not cushionlike +