Aconogonon davisiae

(W. H. Brewer ex A. Gray) Soják

Preslia 46: 151. 1974.

Common names: Davis’s knotweed
Endemic
Basionym: Polygonum davisiae W. H. Brewer ex A. Gray Proc. Amer. Acad. Arts 8: 399. 1872
Synonyms: Aconogonon newberryi (Small) Soják Polygonum newberryi Small
Treatment appears in FNA Volume 5. Treatment on page 599. Mentioned on page 598.
Revision as of 10:12, 30 July 2020 by imported>Volume Importer
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Plants 12–42 (–50) cm. Stems ascending to erect, glabrous or pubescent. Leaves: ocrea reddish-brown, funnelform, 0.3–3 cm, margins oblique, glabrous or finely pubescent to pilose; petiole 0.3–10 (–15) mm; blade oblong-ovate to ovate, rarely broadly lanceolate, 2.1–7.5 (–9.5) × 1.1–5 cm, subcoriaceous, base truncate or, rarely, cordate, margins entire, glabrous or ciliate, apex obtuse to acute, faces often glaucous, glabrous or pubescent. Inflorescences axillary, racemelike; peduncle essentially absent. Pedicels 0.5–1.9 (–2.4) mm. Flowers 1–4 per ocreate fascicle, rarely some flowers with stamens poorly developed; perianth greenish to pinkish white, 2–4.5 mm; tepals slightly dimorphic or, rarely, distinctly so, oblong-ovate to obovate, apex obtuse; anthers yellow or pink. Achenes exserted, yellowish-brown, not beaked distally, 3.2–6 (–8.3) × 2.1–5 mm, shiny, faces not concave. 2n = 20.

Discussion

Varieties 2 (2 in the flora).

The varieties are largely sympatric and often intergrade. The treatment here follows Hong S. P. (1991).

Selected References

None.

Key

1 Faces of leaf blades pubescent, rarely glabrescent Aconogonon davisiae var. davisiae
1 Faces of leaf blades glabrous Aconogonon davisiae var. glabrum

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

... more about "Aconogonon davisiae"
0.6 cm6 mm <br />0.006 m <br /> (0.83 cm8.3 mm <br />0.0083 m <br />) +
yellowish-brown +
0.32 cm3.2 mm <br />0.0032 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
3-gonous +
2.1mm;5mm +
pink +  and yellow +
ovate +  and elliptic +
obtuse;obtuse;acute +
Harold R. Hinds† +  and Craig C. Freeman +
(W. H. Brewer ex A. Gray) Soják +
, +  and truncate +
cordate +
Polygonum davisiae +
7.5 cm75 mm <br />0.075 m <br /> (9.5 cm95 mm <br />0.095 m <br />) +
2.1 cm21 mm <br />0.021 m <br /> (7.5 cm75 mm <br />0.075 m <br />) +
lanceolate;oblong-ovate;ovate +
subcoriaceous +
1.1 cm11 mm <br />0.011 m <br /> (5 cm50 mm <br />0.05 m <br />) +
foliaceous +  and perfoliate +
scale-like +
just below the soil surface or and above the soil surface +  and spreading +
Davis’s knotweed +
Calif. +, Idaho +, Oreg. +  and Wash. +
pubescent +, glabrous +  and glaucous +
not concave +
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 +
compound +, branched +  and simple +
nonmembranous +
sessile +  and petiolate +
deciduous +
glabrous +, finely pubescent +  and pilose +
undulate +
swollen +
partly +  and foliaceous +
reddish-brown +
deciduous +  and persistent +
cylindric +
0.3 cm3 mm <br />0.003 m <br /> (3 cm30 mm <br />0.03 m <br />) +
coriaceous +  and membranous +
anatropous +, , +  and orthotropous +
0.19 cm1.9 mm <br />0.0019 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
accrescent +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.19 cm1.9 mm <br />0.0019 m <br />) +
spreading;erect +
greenish;pinkish white +
nonaccrescent +
0.2 cm2 mm <br />0.002 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
fleshy +, indurate +  and membranous +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (1 cm10 mm <br />0.01 m <br />) +
(2-)3(-4)-carpellate +
slender;stout +
not scapose +
ascending +  and erect +
pubescent +  and glabrous +
penicillate +, fimbriate +  and capitate +
deciduous +  and persistent +
2-lobed +  and cylindric +
coriaceous +  and membranous +
connate +  and distinct +
spreading;erect +
spreading;erect +
Aconogonon newberryi +  and Polygonum newberryi +
Aconogonon davisiae +
Aconogonon +
species +
, +  and dimorphic +
oblong-ovate +  and obovate +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
42 cm420 mm <br />0.42 m <br /> (50 cm500 mm <br />0.5 m <br />) +
11 +, 10 +  and 8 +