0.5g (approx. 100 seeds). (Coronilla varia) This herbaceous perennial plant is about 40 cm (15 in.) tall, branching occasionally. The hairless stems are more or less ascending, often relying on adjacent vegetation for support. Because the stems are produced in abundance from rhizomes, Crown Vetch often forms a dense layer of leafy vegetation that excludes other plants. Each compound leaf is more or less sessile because its first pair of leaflets occurs near the stem. Tendrils are not produced. From the axils of the upper compound leaves, there develops individual flowering stalks. At the apex of each stalk, there is an umbel of 10-25 flowers.