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Davis' knotweed, Newberry's fleeceflower, Newberry's knotweed

Photo is of parent taxon
Habit Plants 12–42(–50) cm.
Stems

ascending to erect, glabrous or pubescent.

glabrous.

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.

blades 2.4–5.8 × 1.2–3.2 cm, base cordate or truncate, faces glabrous.

Inflorescences

axillary, racemelike;

peduncle essentially absent.

Pedicels

0.5–1.9(–2.4) mm.

0.6–1.4 mm, glabrous.

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.

Perianths

3–3.8 mm.

Achenes

exserted, yellowish brown, not beaked distally, 3.2–6(–8.3) × 2.1–5 mm, shiny, faces not concave.

2n

= 20.

Aconogonon davisiae

Aconogonon davisiae var. glabrum

Phenology Flowering Jun–Aug.
Habitat Mountain slopes, talus slopes, edges of serpentine outcrops
Elevation 1000-2200 m (3300-7200 ft)
Distribution
from FNA
CA; ID; OR; WA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; WA
Discussion

Varieties 2 (2 in the flora).

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

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Faces of leaf blades pubescent, rarely glabrescent
var. davisiae
1. Faces of leaf blades glabrous
var. glabrum
Source FNA vol. 5, p. 599. FNA vol. 5, p. 600.
Parent taxa Polygonaceae > subfam. Polygonoideae > Aconogonon Polygonaceae > subfam. Polygonoideae > Aconogonon > Aconogonon davisiae
Sibling taxa
A. alaskanum, A. phytolaccifolium
A. davisiae var. davisiae
Subordinate taxa
A. davisiae var. davisiae, A. davisiae var. glabrum
Synonyms Polygonum davisiae, A. newberryi, Polygonum newberryi Polygonum newberryi var. glabrum
Name authority (W. H. Brewer ex A. Gray) Soják: Preslia 46: 151. (1974) (G. N. Jones) S. P. Hong: Rhodora 93: 343. (1991)
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