Halopteris glutinosa (Lamouroux, 1816)

Colonies short and robust, with deeply incised stem joints; frequently an extra oblique septal internodal ridge is developed just below the adcauline hydrothecal wall. Colonies from deeper or more sheltered water have more flexuous stems with indistinct cauline nodes, and also lack the oblique hydrocladial septa present in shallower water specimens. The deeper water stems scarlet in colour, whereas shallower water specimens wary from orange to yellow.