Aconogonon davisiae

(W. H. Brewer ex A. Gray) Soják

Preslia 46: 151. 1974

Common names: Davis’s knotweed
Basionyms: 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).

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