This is one of the most beautiful of the British species of
Cystoseira, especially when seen growing under water. It then
appears clothed with the richest tints of blue and green, more
like those phosphorescent gleams that flash from the lower marine
animals than any vegetable colours. As each twig waves to and
fro in the water the hues vary, and sometimes, when the light
falls partially on a branch, some portions seem covered with sky-
blue flowers, while others remain dark. All these beautiful tints
perish when the plant is removed from the water. The specific
name ericoides, or heath-like, alludes both to the brilliant colouring
and the shrubby character of the frond, w'hich is covered with
small ramuli resembling the leaves of a heath.
C. ericoides is common on the southern shores of our islands,
and becomes gradually less frequent towards the north. It has
been once found on the coast of Ayrshire by the Rev. D. Landsborough.
Fig. 1. Cystoseira ERICOIDES :■—o f the natural m e, 3. Feceptacle and vesicle,
both formed in the apex of a branch. 3. Section of a conceptacle, showing
the spores and antheridia. 4. A spore :— all more ’ ’