Florideophyceae


Florideophyceae is a class of exclusively multicellular red algae. They were once thought to be the only algae to bear pit connections, but these have since been found in the filamentous stage of the Bangiaceae. They were also thought only to exhibit apical growth, but there are genera known to grow by intercalary growth. Most, but not all, genera have three phases to the life cycle. In the subclass Nemaliophycidae there are three orders, Balbianiales, Batrachospermales, and Thoreales, which lives exclusively in freshwater.

Classification

There are various classification schemes; see red algae. One option is to use the following:

Subclass [Hildenbrandiophycidae]

Subclass [Nemaliophycidae]

Subclass [Corallinophycidae]

The subclass Corallinophycidae was introduced in 2007.

Subclass [Ahnfeltiophycidae]

Subclass [Rhodymeniophycidae]

According to molecular clock analysis, Florideophyceae diverged from other red algae about 943 million years ago. It split into Hildenbrandiophycidae ca. 781 mya, Nemaliophycidae ca. 661 mya and Corallinophycidae ca. 579 mya, and ca. 508 mya the split between Ahnfeltiophycidae and Rhodymeniophycidae occurred.