Polygonum cascadense

W. H. Baker

Madroño 10: 62, plate 1, fig. 1. 1949.

Common names: Cascade knotweed
Endemic
Treatment appears in FNA Volume 5. Treatment on page 571. Mentioned on page 561, 562.

Herbs. Stems spreading to erect, zigzagged, green, simple or branched from base, wiry, 5–12 (–15) cm, glabrous. Leaves uniformly distributed, articulated to ocreae, basal leaves persistent, distal leaves abruptly reduced to bracts; ocrea 2–5 mm, glabrous, proximal part funnelform, distal part lacerate; petiole essentially absent; blade 1-veined, not pleated, oblanceolate to obovate, 5–20 × 2–5 mm, margins revolute, never touching along midrib, sparsely papillose-denticulate, apex rounded or apiculate. Inflorescences axillary and terminal, spikelike, dense; cymes congested at tips of stems and branches, 3–5-flowered. Pedicels enclosed in ocreae, erect to spreading, 2–3 mm. Flowers open; perianth 2–2.5 mm; tube 12–25% of perianth length; tepals overlapping, uniformly white, petaloid, oblong to obovate, cucullate, navicular in distal 1/4, apex rounded; midveins unbranched; stamens 8. Achenes enclosed in or exserted from perianth, black, ovate to ovate-oblong, 1.8–2.1 mm, faces subequal, shiny, smooth.


Phenology: Flowering Jun–Sep.
Habitat: Dry, usually rocky slopes, often on serpentine
Elevation: 1600-1800 m

Discussion

Selected References

None.

Lower Taxa

None.

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

... more about "Polygonum cascadense"
reticulate +, tubercled +  and smooth +
exserted +  and included +
dull +  and shiny +
ovate +  and ovate-oblong +
pink +  and purple +
elliptic +  and oblong +
rounded;papillose-denticulate +
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
W. H. Baker +
not stipelike +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
oblanceolate;obovate +
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 +
Cascade knotweed +
3-5-flowered +
1600-1800 m +
subequal +
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 +
Dry, usually rocky slopes, often on serpentine +
compound +, branched +  and simple +
nonmembranous +
articulated +
distributed +
deciduous +
not rugulose +
apiculate +  and rounded +
swollen +
silvery +, white +  and hyaline +
disintegrating +
deciduous +  and persistent +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
coriaceous +  and membranous +
somewhat larger +
anatropous +, , +  and orthotropous +
erect;spreading +
accrescent +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
spreading;erect +
greenish white;pink +
campanulate +  and urceolate +
nonaccrescent +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
fleshy +, indurate +  and membranous +
not +  and articulated +
Flowering Jun–Sep. +
(2-)3(-4)-carpellate +
papillose-scabridulous +  and smooth +
slender;stout +
woody +  and fibrous +
wiry +, branched +  and simple +
12 cm120 mm <br />0.12 m <br /> (15 cm150 mm <br />0.15 m <br />) +
zigzagged +  and straight +
spreading +  and erect +
papillous-scabridulous +
4-gonous +
5 cm50 mm <br />0.05 m <br /> (12 cm120 mm <br />0.12 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 cascadense +
Polygonum sect. Duravia +
species +
overlapping +
connate +  and distinct +
navicular +, cucullate +, oblong +  and obovate +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
heterophyllous +  and homophyllous +