Classification
Class
Magnoliopsida Brongn.
Order
Caryophyllales Juss. ex Bercht. & J.Presl
Family
Polygonaceae
Genus
Polygonum L.
 Nomenclature
Scientific Name:
Polygonum plebeium R.Br.
Vernacular Name(s):
Small knotweed
 Description

Prostrate, nearly glabrous, mat-forming herb; taproot present; stems usually < 15 cm long, with angles minutely puberulent. Lvs all similar, sessile. Lamina 3–9 × 0.5–1.5 mm, linear or slightly spathulate, granular-punctate, entire; lateral veins not evident but midrib conspicuous; base attenuate; apex obtuse or subacute. Ochreae to c. 3 mm long, silvery-hyaline, soon lacerate with aristate points, often enclosing nearly 1/2 the internode. Fls axillary, in fascicles of 1–5; pedicels to c. 0.5 mm long at anthesis, usually enclosed by ochreae. Perianth c. 1 mm long at anthesis, pinkish, accrescent; segments imbricate, oblong. Nut 1.2–1.7 mm long, ovoid, dark brown or black, smooth, glossy, triquetrous with ridges obtusely angled.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]

 Biostatus
Indigenous (Non-endemic)
 Phenology

Flowering: Nov.–Mar.

 Bibliography
de Lange, P.J.; Norton, D.A.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Hitchmough, R.; Townsend, A.J. 2009: Threatened and uncommon plants of New Zealand (2008 revision). New Zealand Journal of Botany 47: 61–96. [Data deficient]
de Lange, P.J.; Norton, D.A.; Heenan, P.B.; Courtney, S.P.; Molloy, B.P.J.; Ogle, C.C.; Rance, B.D. 2004: Threatened and uncommon plants of New Zealand. New Zealand Journal of Botany 42(1): 45–76.
de Lange, P.J.; Rolfe, J.R.; Barkla J.W.; Courtney, S.P.; Champion, P.D.; Perrie, L.R.; Beadel, S.N.; Ford, K.A.; Breitwieser, I.; Schönberger, I.; Hindmarsh-Walls, R.; Heenan, P.B.; Ladley, K. 2018: Conservation status of New Zealand indigenous vascular plants, 2017. New Zealand Threat Classification Series. No. 22. [Declining]
de Lange, P.J.; Rolfe, J.R.; Champion, P.D.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Norton, D.A.; Hitchmough, R.A. 2013: Conservation status of New Zealand indigenous vascular plants, 2012. New Zealand Threat Classification Series 3. Department of Conservation, Wellington. [Data Deficient]