Polygonum bidwelliae

S. Watson

Proc. Amer. Acad. Arts 14: 294. 1879.

Common names: Bidwell’s knotweed
IllustratedEndemic
Treatment appears in FNA Volume 5. Treatment on page 565. Mentioned on page 561.

Herbs. Stems erect, green, simple or divaricately branched, ± wiry, 2–20 cm, minutely papillose-scabridulous. Leaves crowded at branch tips, not articulated to ocreae, basal leaves caducous or persistent, distal leaves abruptly reduced to bracts; ocrea 8–13 mm, papillose-scabridulous, proximal part cylindric, distal part overlapping and obscuring leaves and flowers, silvery, entire or shallowly dentate; petiole absent; blade 3-veined, without pleats, linear, 5–15 (–20) × 0.5–1.5 (–2) mm, margins revolute, papillose-denticulate, apex spine-tipped. Inflorescences axillary; cymes in distal axils, 1-flowered. Pedicels absent. Flowers closed; perianth 2–3 mm; tube 10–18% of perianth length; tepals overlapping, pink with pink or white margins, petaloid, elliptic, navicular, apex acute to acuminate; midveins unbranched; stamens 8. Achenes enclosed in perianth at maturity, light-brown to brown, ovate-elliptic, 1.8–2.3 mm, faces subequal, shiny, smooth.


Phenology: Flowering May–Jun.
Habitat: Thin volcanic soils, chaparral, montane woodland valleys, grasslands
Elevation: 60-1200 m

Discussion

Polygonum bidwelliae occurs in the Cascade Range and northeastern Sacramento Valley in Butte, Shasta, and Tehama counties.

Selected References

None.

Lower Taxa

None.

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

... more about "Polygonum bidwelliae"
reticulate +, tubercled +  and smooth +
black;brown;black;brown;yellow-green +
exserted +  and included +
dull +  and shiny +
3-gonous +, ovate +  and elliptic or lanceolate +
pink +  and purple +
elliptic +  and oblong +
acute;acuminate +
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
S. Watson +
persistent +  and caducous +
not stipelike +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
narrowly linear;subround +
coriaceous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
foliaceous +  and perfoliate +
scale-like +
just below the soil surface or and above the soil surface +  and spreading +
Bidwell’s knotweed +
60-1200 m +
subequal +
adnate +, free +  and distinct +
semi-open +  and open +
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 +
Thin volcanic soils, chaparral, montane woodland valleys, grasslands +
compound +, branched +  and simple +
nonmembranous +
not articulated +
deciduous +
white +  and pink +
not rugulose +
papillose-denticulate +
swollen +
silvery +, white +  and hyaline +
disintegrating +
deciduous +  and persistent +
papillose-scabridulous +
0.8 cm8 mm <br />0.008 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
coriaceous +  and membranous +
somewhat larger +
anatropous +, , +  and orthotropous +
erect;spreading or reflexed +
accrescent +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
spreading;erect +
greenish white;pink +
campanulate +  and urceolate +
nonaccrescent +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
fleshy +, indurate +  and membranous +
not +  and articulated +
Flowering May–Jun. +
(2-)3(-4)-carpellate +
Proc. Amer. Acad. Arts +
papillose-scabridulous +  and smooth +
slender;stout +
woody +  and fibrous +
Illustrated +  and Endemic +
wiry +, branched +  and simple +
zigzagged +  and straight +
papillose-scabridulous +
4-gonous +
2 cm20 mm <br />0.02 m <br /> (20 cm200 mm <br />0.2 m <br />) +
2 +  and 3 +
penicillate +, fimbriate +  and capitate +
deciduous +  and persistent +
2-lobed +  and cylindric +
coriaceous +  and membranous +
connate +  and distinct +
spreading;erect +
Undefined sect. Duravia +  and Polygonum sect. Monticola +
Polygonum bidwelliae +
Polygonum sect. Duravia +
species +
overlapping +
connate +  and distinct +
navicular +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
heterophyllous +  and homophyllous +