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.

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 +
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 +
1.1cm;5cm +
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 />) +
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 +
penicillate +, fimbriate +  and capitate +
deciduous +  and persistent +
? (?) +  and ? (?) +
coriaceous +  and membranous +
connate +  and distinct +
spreading;erect +
Aconogonon newberryi +  and Polygonum newberryi +
Aconogonon davisiae +
Aconogonon +
species +
, +  and dimorphic +
oblong-ovate +  and obovate +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
11 +, 10 +  and 8 +