Polygonum shastense

W. H. Brewer

Proc. Amer. Acad. Arts 8: 400. 1872.

Common names: Shasta knotweed
IllustratedEndemic
Treatment appears in FNA Volume 5. Treatment on page 563. Mentioned on page 561.

Subshrubs. Stems prostrate to ascending, brown, branched, gnarled, not wiry, 5–40 cm, glabrous. Leaves ± uniformly distributed, articulated to ocreae, basal leaves caducous or persistent, distal leaves not reduced in size; ocrea 3–5 mm, glabrous, proximal part cylindric, distal part membranous, deciduous with leaves; petiole 0–0.5 mm; blade 1-veined, without pleats, lanceolate to elliptic, 5–25 × 2–5 mm, coriaceous, margins revolute, smooth, apex acute. Inflorescences axillary; cymes in distal axils, 2–6-flowered. Pedicels enclosed in or slightly exserted from ocreae, erect, 2–4 mm. Flowers open or semi-open; perianth 5–9 mm; tube 7–15% of perianth length, tepals partially overlapping, uniformly pink or white, petaloid, ovate to ovate-round, apex rounded; midveins with numerous branched lateral-veins; stamens 8. Achenes enclosed in or slightly exserted from perianth, brown, narrowly ovate, 3–4 mm, faces subequal, shiny, smooth.


Phenology: Flowering Jul–Sep.
Habitat: Rocky or gravelly slopes
Elevation: 2100-3400 m

Discussion

Polygonum shastense may be cultivated in rock gardens in rock crevices with favorable water regime and shaded in summer.

Selected References

None.

Lower Taxa

None.

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

... more about "Polygonum shastense"
reticulate +, tubercled +  and smooth +
exserted +  and included +
dull +  and shiny +
pink +  and purple +
elliptic +  and oblong +
rounded;acute +
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
W. H. Brewer +
persistent +  and caducous +
not stipelike +
0.5 cm5 mm <br />0.005 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
lanceolate;elliptic +
coriaceous +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
foliaceous +  and perfoliate +
scale-like +
just below the soil surface or and above the soil surface +  and spreading +
Shasta knotweed +
2-6-flowered +
not reduced +
Calif. +, Nev. +  and Oreg. +
2100-3400 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 +
Rocky or gravelly slopes +
compound +, branched +  and simple +
nonmembranous +
articulated +
distributed +
deciduous +
not rugulose +
papillose-denticulate +
swollen +
silvery +, white +  and hyaline +
disintegrating +
deciduous +  and persistent +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
coriaceous +  and membranous +
somewhat larger +
anatropous +, , +  and orthotropous +
accrescent +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
spreading;erect +
greenish white;pink +
campanulate +  and urceolate +
nonaccrescent +
0.5 cm5 mm <br />0.005 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
fleshy +, indurate +  and membranous +
not +  and articulated +
0 cm0 mm <br />0 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
Flowering Jul–Sep. +
(2-)3(-4)-carpellate +
Proc. Amer. Acad. Arts +
papillose-scabridulous +  and smooth +
slender;stout +
woody +  and fibrous +
Illustrated +  and Endemic +
not wiry +  and branched +
zigzagged +  and straight +
prostrate +  and ascending +
papillous-scabridulous +
4-gonous +
5 cm50 mm <br />0.05 m <br /> (40 cm400 mm <br />0.4 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 shastense +
Polygonum sect. Duravia +
species +
overlapping +
white +  and pink +
connate +  and distinct +
ovate +  and ovate-round +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
heterophyllous +  and homophyllous +