Coralline Algae - Morphological Forms

Morphological Forms

Traditionally, corallines have been divided into two groups, although this division does not constitute a taxonomic grouping:

• the geniculate (articulated) corallines;
• the nongeniculate (nonarticulated) corallines.

Geniculate corallines are branching, tree-like plants which are attached to the substratum by crustose or calcified, root-like holdfasts. The plants are made flexible by having noncalcified sections (genicula) separating longer calcified sections (intergenicula). Nongeniculate corallines range from a few micrometres to several centimetres thick crusts. They are often very slow growing, and may occur on rock, coral skeletons, shells, other algae or seagrasses. Crusts may be thin and leafy to thick and strongly adherent. Some are parasitic or partly endophytic on other corallines. Many coralline crusts produce knobby protuberances ranging from a millimetre to several centimetres high. Some are free-living as rhodoliths (rounded, free-living specimens).