This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
The habitat of this plant is salt marshes, ballast hills. The plant has the shrub habit. The stems are creeping, slightly downy, prostrate, wiry. The leaves are in whorls or clusters, with rolled-back margins, adapted to dry conditions, linear-oblong, hairless (hence Isevis), or fringed with hairs at the base. The flowers are small, rose colour, terminal, or in the forks stalkless. The calyx is slightly hairy between the prominent angles, the sepals forming a tubular calyx with 4-5 sepals. The petals are 4-5, the claws long, the laminae spreading. The capsule is 3-sided, the seeds are small, and the embryo is straight, surrounded by albumen. The plant is creeping. It flowers between June and September. The plant is a herbaceous or shrubby perennial.