Polygonum nuttallii

Small

Mongr. Amer. Sp. Polygonum, 132, plate 53. 1895.

Common names: Nuttall’s knotweed
Endemic
Basionym: Polygonum intermedium Nuttall ex S. Watson Proc. Amer. Acad. Arts 17: 378. 1882,
Synonyms: Polygonum douglasii subsp. nuttallii (Small) J. C. Hickman
Treatment appears in FNA Volume 5. Treatment on page 570. Mentioned on page 561, 562, 568.

Herbs. Stems spreading to erect, sometimes zigzagged, purplish, simple or branched, wiry, (5–) 10–35 cm, papillose-scabridulous. Leaves evenly distributed or crowded at branch tips, articulated to ocreae, basal leaves persistent, distal leaves gradually reduced to bracts; ocrea 3–4 mm, papillose-scabridulous, proximal part funnelform, distal part finely lacerate; petiole 0.1–2 mm; blade 1-veined, not pleated, linear to narrowly oblongelliptic, 8–30 × 1–4 (–7) mm, margins narrowly revolute, never touching along midrib, smooth, apex acute, mucronate, ± glaucous adaxially. Inflorescences axillary and terminal, spikelike, dense; cymes mostly congested toward tips of branches, 2–3-flowered. Pedicels enclosed in ocreae, erect to spreading, 2–3 mm. Flowers semi-open or closed; perianth 1.8–2.4 mm; tube 25–33% of perianth length; tepals overlapping, greenish, white, or pink with pink margins, petaloid, oblong, cucullate, navicular in distal 1/4, apex rounded; midveins unbranched; stamens 8. Achenes enclosed in perianth, black, elliptic to ovate, 1.8–2.3 mm, faces subequal, shiny, smooth.


Phenology: Flowering May–Oct.
Habitat: Dry prairies, open knolls in lower mountains, open sites in lowland and montane zones, sandy soil
Elevation: 800-1100 m

Discussion

C. L. Hitchcock (1964) suggested that Polygonum nuttallii is but a small-flowered form of P. spergulariiforme. Although morphologically similar, P. nuttallii differs from P. spergulariiforme in some respects, including its wiry, purplish stems, short and funnelform ocreae, adaxially glaucous leaves, longer bracts, shorter fruiting perianth, and achenes.

Selected References

None.

Lower Taxa

None.

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

... more about "Polygonum nuttallii"
reticulate +, tubercled +  and smooth +
exserted +  and included +
dull +  and shiny +
elliptic +  and ovate +
pink +  and purple +
elliptic +  and oblong +
rounded;mucronate;acute +
Mihai Costea +, François J. Tardif +  and Harold R. Hinds† +
not stipelike +
Polygonum intermedium +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (3 cm30 mm <br />0.03 m <br />) +
linear;narrowly oblongelliptic +
coriaceous +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
foliaceous +  and perfoliate +
scale-like +
just below the soil surface or and above the soil surface +  and spreading +
Nuttall’s knotweed +
2-3-flowered +
B.C. +, Oreg. +  and Wash. +
800-1100 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 prairies, open knolls in lower mountains, open sites in lowland and montane zones, sandy soil +
compound +, branched +  and simple +
nonmembranous +
articulated +
crowded +  and distributed +
deciduous +
not rugulose +
papillose-denticulate +
swollen +
silvery +, white +  and hyaline +
disintegrating +
deciduous +  and persistent +
papillose-scabridulous +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 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 +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
fleshy +, indurate +  and membranous +
not +  and articulated +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Flowering May–Oct. +
(2-)3(-4)-carpellate +
Mongr. Amer. Sp. Polygonum, +
papillose-scabridulous +  and smooth +
slender;stout +
woody +  and fibrous +
wiry +, branched +  and simple +
5 cm50 mm <br />0.05 m <br /> (10 cm100 mm <br />0.1 m <br />) +
zigzagged +  and straight +
spreading +  and erect +
papillose-scabridulous +
4-gonous +
10 cm100 mm <br />0.1 m <br /> (35 cm350 mm <br />0.35 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 douglasii subsp. nuttallii +
Polygonum nuttallii +
Polygonum sect. Duravia +
species +
overlapping +
pink +, white +  and greenish +
connate +  and distinct +
navicular +, cucullate +  and oblong +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
heterophyllous +  and homophyllous +