A genus of red seaweeds which includes only one British species: C. crispus (Irish moss). The thallus is rather variable in both form and colour. The fronds are flattened and strap-like, extensive dichotomous branching giving rise to a bushy, tufted habit. They are usually purplish-red, but may be green in strong sunlight. They are found attached to rocks in pools on the lower part of the intertidal region, and below the low-water mark.
Subjects: Plant Sciences and Forestry.