Chickweeds are low, mostly glandular-hairy annual, biennial, or perennial herbs, often rooting at the nodes and forming mats. The leaves are opposite, without stipules. The flowers have its parts attached on the receptacle below the ovary. They are not showy, usually arranged in terminal, branching, open to congested clusters, but sometimes single and terminal. There are 5 sepals, separated to the base, usually membranous-edged. The 5 petals are white, rarely lacking, always notched, with rounded points or 2-lobed, not narrowed to a stalk. The stamens are commonly 10, sometimes 5. There are usually 5 styles in our species, which are separated to the base, situated opposite the sepals. The capsule is 1-celled, delicately membranous, cylindric, rather characteristically slightly curved in the upper half. In our species the capsule is usually 2-3 times as long as the calyx, the tip opening by a lid-like top, splitting open by 10 usually rolled backward, lengthwise-edged teeth. The capsule contains many seeds, which are rather prominently covered with very small warty bumps in concentric rows. The genus consists of about 100 species worldwide, cosmopolitan in distribution but mostly in the north temperate region of Eurasia. The name comes from the Greek keras, horn, in reference to the general shape of the capsule.
Guide to Identify Presented Species of Genus Cerastium
PETALS NOT MUCH LONGER THAN SEPALS
C. fontanum Common Chickweed Loosely tufted herb with long hairs. New, leafy shoots growing from bases.
Flowers small, white, with petals only slightly longer than the sepals.
Leaves egg-shaped, hairy, with blunt tips.