Polygonella americana

(Fischer & C. A. Meyer) Small

Mem. Torrey Bot. Club 5: 141. 1894.

Common names: American jointweed southern jointweed
IllustratedEndemic
Basionym: Gonopyrum americanum Fischer & C. A. Meyer Mém. Acad. Imp. Sci. Saint-Pétersbourg, Sér. 6, Sci. Math., Seconde Pt. Sci. Nat. 4: 144. 1840
Treatment appears in FNA Volume 5. Treatment on page 539. Mentioned on page 535.

Subshrubs, perennial, synoecious, 5.5–9 dm. Stems erect, branched proximally and basally, glabrous. Leaves persistent; ocrea margins not ciliate; blade linear to spatulate, (4–) 5–12 (–19) × 0.5–0.9 (–1.2) mm, base barely tapered, margins not hyaline, apex obtuse to acute, often erose, glabrous. Inflorescences (7–) 18–30 (–60) mm; ocreola encircling rachis, only the base adnate to rachis, apex acuminate. Pedicels spreading in anthesis and fruit, 0.4–2.3 mm, usually much longer than subtending ocreola. Flowers bisexual; outer tepals sharply reflexed early in anthesis and in fruit, white to pink, elliptic to ovate, 1.2–2.2 mm in anthesis, margins erose; inner tepals loosely appressed in anthesis and fruit, white to pink, ovate to suborbiculate, 1.7–2.9 mm in anthesis, margins erose; filaments dimorphic; anthers yellow or pink; styles and stigmas 0.5–1 mm in anthesis. Achenes included, reddish-brown, 3 (–4) -gonous, 2.5–4 × 1.3–2.3 mm, shiny, smooth. 2n = 36.


Phenology: Flowering Jun–Oct.
Habitat: Sandy roadsides, fields, riverbanks, scrub forests, waste places
Elevation: 10-200 m

Distribution

V5 1105-distribution-map.gif

Ala., Ark., Ga., La., Mo., N.Mex., Okla., S.C., Tex.

Discussion

Selected References

None.

Lower Taxa

None.

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

... more about "Polygonella americana"
winged +  and wingless +
reddish-brown +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
3(-4)-gonous +
1.3mm;2.3mm +
pink +  and yellow +
elliptic +  and ovate or round +
acuminate;obtuse;acute +
Craig C. Freeman +
(Fischer & C. A. Meyer) Small +
tapered +
Gonopyrum americanum +
1.2 cm12 mm <br />0.012 m <br /> (1.9 cm19 mm <br />0.019 m <br />) +
0.09 cm0.9 mm <br />9.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
linear;spatulate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
foliaceous +  and perfoliate +
scale-like +
just below the soil surface or and above the soil surface +  and spreading +
American jointweed +  and southern jointweed +
Ala. +, Ark. +, Ga. +, La. +, Mo. +, N.Mex. +, Okla. +, S.C. +  and Tex. +
10-200 m +
curved +  and straight +
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 +
Sandy roadsides, fields, riverbanks, scrub forests, waste places +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
1.8 cm18 mm <br />0.018 m <br /> (3 cm30 mm <br />0.03 m <br />) +
ovate +  and suborbiculate +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.29 cm2.9 mm <br />0.0029 m <br />) +
nonmembranous +
persistent +
not hyaline +
pubescent +  and glabrous +
lobed +, undulate +, crisped +, crenulate +  and entire +
swollen +
partly +  and foliaceous +
disintegrating +
deciduous +  and persistent +
cylindric +
coriaceous +  and chartaceous +
3 +  and 5 +
5 +, 1 +  and 2 +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
anatropous +, , +  and orthotropous +
usually much longer +
accrescent +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
spreading;erect +
yellowish;greenish;yellowish;greenish;red;pink;white +
campanulate +
nonaccrescent +
fleshy +, indurate +  and membranous +
Flowering Jun–Oct. +
(2-)3(-4)-carpellate +
Mem. Torrey Bot. Club +
slender;stout +
horned +  and toothed +
Illustrated +  and Endemic +
prostrate +  and decumbent +
penicillate +, fimbriate +  and capitate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (?) +  and 0.1 cm1 mm <br />0.001 m <br /> (?) +
deciduous +  and persistent +
2-lobed +  and cylindric +
coriaceous +  and membranous +
distinct +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (?) +  and 0.1 cm1 mm <br />0.001 m <br /> (?) +
spreading;erect +
Polygonella americana +
Polygonella +
species +
transitional +  and petaloid +
distinct +
lobed +  and laciniate +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +