Sagina apetala Ard.

Common Pearlwort

Annual with erect stems to 10 cm tall. Leaves to 1 cm long, distinctly bristled. Flowers usually 4-parted, stalks longer than the leaves, petals extremely small, falling early.

Europe, Scandinavia

Source: Spencer, R. (1997). Caryophyllaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.

kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Caryophyllanae
order      Caryophyllales
family       Caryophyllaceae
genus        Sagina L.