Polycarpon tetraphyllum (allseed)

This small plant is a member of the Caryophyllaceae family, that was first recorded in New Zealand in 1854 (2).

Esler describes it as a ‘low herb of open soil’ (1). Webb et al. describe the habitat for this species as including “gravelly or sandy sites, coastal and inland, riverbeds, roadsides, railway ballast, seashore, waste land, cultivated land, grassland” (3).

Polycarpon tetraphyllum (allseed)

Allseed has ‘dust seeds’ - these are very small seeds that weigh <0.1 mg (1). The small seeds are one of the features that enable its wide distribution, which can be seen here.

There are many good photos of this species on iNaturalist.

References:

  1. Esler, A. E. The naturalisation of plants in urban Auckland, New Zealand 4. The nature of the naturalised species. N. Z. J. Bot. 26, 345–385 (1988).

  2. Garnock-Jones, P. J. Checklist of dicotyledons naturalised in New Zealand 8. Aizoaceae, Caryophyllaceae, and Portulacaceae. N. Z. J. Bot. 19, 59–65 (1981).

  3. Webb, C., Sykes, W. & Garnock-Jones, P. Flora of New Zealand. Volume IV. Naturalised pteridophytes, gymnosperms, dicotyledons. (Botany Division, D.S.I.R., 1988).