Hoary Cress

Cardaria draba

Alternative Name(s): White Weed

Family: Brassicaceae.

Form: Herb

Origin: Native of eastern Mediterranean to central and southern Asia.

Flowers/Seedhead: In terminal, often umbrella-like, clusters. Flowers fragrant with sepals to 2.5 mm long, white petals to 4.5 mm long and six stamens. Flowers most of year but mainly spring and summer.

Description: Erect perennial herb to 90 cm high. Stems with longitudinal ribs. Leaves grey-green; basalones ovate to elliptic to 15 cm long, margins entire or toothed, on a stalk; stem leaves ovate to oblong to8 cm long, margins entire to toothed, without a stalk and base stem-clasping. Mature fruit with a network of surface veins, on a stalk 4–15 mm long. Seeds ovoid, to 2.5 mm long, not winged, dark red-brown.

Distinguishing features: Distinguished by spreading rhizomatous root system; dense covering of short hairs; heart-shaped fruit with the broadest part towards the base, to 4 (rarely to 5) mm long and generally wider with remains of style at top, almost hairless; fruit not opening at maturity but separating into two 1-seeded sections.

Dispersal: Spreads by buds on spreading roots, movement of root sections and by seed. Regrows from perennial rootstock. Plants may produce up to5000 seeds with high viability although most spread is by movement of pieces of root.