Persicaria orientalis (L.) Spach

Hairy, fibrous-rooted annual with erect stems 20–150–(250) cm tall. Lvs on main stem similar to those on branches; petiole to c. 10 cm long, densely hispid. Lamina 7–25 × 4–17 cm, ovate, entire, with margin and veins densely hispid above and below, otherwise hairs sparser; base rounded to cordate, broadly cuneate on infl. lvs; apex cuspidate. Ochreae c. 2 cm long on main part of stem, green, with apical lobes prominently setose. Infl. a large open panicle with densely hairy branches terminating in dense pendulous spikes (1)–3–8 cm long; pedicels to 5 mm long, enclosed by bracts until anthesis; bracts 4–6 mm long, scarious, with appressed hairs, densely ciliate. Perianth 3–5 mm long, crimson in bud, somewhat paler at anthesis, accrescent, eglandular; segments broad-ovate to broad-elliptic, imbricate. Nut c. 4 mm long, broad-ovoid and ± biconvex, glossy black, with a shallow depression in the middle on each side.

[From: Webb et al. (1985) Flora of New Zealand. Volume 4 as Polygonum orientale L.]