June 2014. A weed in potato field at Tambul, Western Highlands, Papua New Guinea.
It was identified as Polygonum nepalense Meisn (Polyonaceae). Very common in highlands gardens and moist open areas. Please send specimens to Robert Kiapranis at the Lae-based National Herbarium for identification.
Another member wrote: apparently, it is considered to be native in the Malesian region which includes PNG. The earliest record in the PNG National Herbarium is from 1918. The entry in Womersley et al. (1978), Handbooks of the Flora of Papua New Guinea Volume 1, notes that it is widespread at altitudes from 1200 – 3000m above sea level where it occurs in disturbed forest and abandoned gardens as well as cropped areas. I have observed and collected it in the Telefomin area of Sandaun Province.
It is also illustrated in: Henty, E. E. and G. H. Pritchard (1975). Weeds of New Guinea and Their Control. Botany Bulletin No. 7. Lae, Division of Botany, Department of Forests. See p138. And in :
Henty, E. E. (1970). Weeds of Coffee in the Central Highlands. Botany Bulletin No. 4, Lae, Division of Botany, Territory of Papua and New Guinea. See p.19.
A worthwhile project for the two PNG research bodies, NARI (agriculture) and FRI (forestry, botany), could be to digitise these manuals (and others), and make them available on the web? (Perhaps updated with colour photographs?)