Global description
Cerastium glomeratum is a small annual herb, yellowish-green in color, entirely pubescent, erect or creeping then ascending, with a stem 50 cm long. The leaves are opposite and simple, obovate to elliptic, pointed end, triangular base, silky hairs on the 2 sides. The flowers are small, white and are grouped in dense cyme. The fruit is a cylindrical capsule which is a little curvy, and that contains numerous discoid seeds.
Cotyledons
The cotyledons (3 to 5 mm long and 1.5 to 2 mm wide) have an oval lamina with a rounded tip and short petiole (1 mm) which is well defined.
First leaves
The seedling has opposite leaves arranged in a rosette. The first 2 leaves are oval-elliptic, and the following are elliptic to obovate. All shrink into a short, wide petiole and are fully covered with a hairy pubescence.
General habit
Small annual herb, yellowish-green in color, completely covered with spreading hairs, erect or creeping then ascending, with stems measuring between 2 cm to 50 cm long.
Underground system
The plant has a taproot system.
Leaf
The leaves are opposite and simple. The basal leaves are obovate, with a triangular base gradually attenuated like a petiole. The caulinary leaves are sessile, obovate or elliptic, acute to obtuse at the end, wedged base, and with silky pubescent on the 2 sides.
Inflorescence
The flowers are small, and are grouped in dense cyme. The stalks are short, glandular. The bracts are herbaceous.
Flower
The five sepals (4 to 6 mm long) are narrowly oval lanceolate, with an acute tip, hairy to the end, glandular on the back and with scarious edges. The 5 petals are about 4 mm long, white in color with yellow base, and barely larger than the sepals. They are oblong-spatulate with bifurcated end, the notch reaching one quarter of the length. The petals may be absent on the internal flowers and sometimes on all the flowers. Stamens (5 to 10) are 2 mm long. The ovoid ovary has 5 styles.
Fruit
The fruit is a slightly curved cylindrical capsule, 7 to 8 mm long, which opens by 10 erect triangular flaps. It contains many seeds.
Seed
The seed is discoid, compressed, surface decorated with tubercles arranged concentrically.