This seedling has been found in two locations: Cornwallis (Auckland) & Claris (Great Barrier Island). Soft, slightly hairy on the underside & along the margins of the leaf. Toothed at the tip of the leaf.
another seedling photo
It would be more useful to wait until flowering but Boraginaceae and Caryopghyllaceae spring to mind and if I was pushed I'd say this is a species of Cerastium (Caryophyllaceae). Out of interest are you working with seed banks for research?
These have been planted since November 2016 (seedling emergence since roughly mid November). Not sure it's Cerastium - as they tend to grow a lot quicker? Yes - researching soil seed banks in post-fire sites in Auckland & Northland.
Good then my suggestion is you let it grow on and flower.
Hi Alicia, not great photos, but don't think they are Boraginaceae or Cerastium as there are teeth towards the tip of the leaf, but no idea what they actually are. Post photos of flower or fruit or adult plant when available.
(JPG format, max 500kB)