Yellow wall bedstraw

Galium murale, the yellow wall bedstraw or small goosegrass, is a minute annual herb in the family Rubiaceae native to the Mediterranean basin and now naturalised in parts of western Europe, North America, and Australasia. Plants are diminutive, only 3-15 cm tall, with slender, decumbent to ascending, four-angled stems that are minutely retrorse-prickly along the angles. Whorls of four to six tiny, narrowly elliptic to oblanceolate leaves about 2-5 mm long, ending in a short apical bristle, are spaced along the stems. From spring into early summer, a few minute yellow flowers about 0.7 mm wide are produced singly or in small clusters from the upper leaf axils. The pair of mericarps is granular-roughened and disperses by adhering to clothing and animals. The species favours open, disturbed, calcareous ground, paths, walls, and gravel.