Florideophyceae
Class of algae
From Wikipedia, the free encyclopedia
Florideophyceae is a class of exclusively multicellular red algae.[3][4] They were once thought to be the only algae to bear pit connections,[5] but these have since been found in the filamentous stage of the Bangiaceae.[6] They were also thought only to exhibit apical growth, but there are genera known to grow by intercalary growth.[6] Most, but not all, genera have three phases to the life cycle.[6] In the subclass Nemaliophycidae there are three orders, Balbianiales, Batrachospermales, and Thoreales, which lives exclusively in freshwater.[7] When alive, the Florideophyceae appear bright red or even violet. However, when placed in cold freshwater, their red pigment dissolves, causing the algae to turn green.[8]
Cronquist, 1960[2]
| Florideophyceae Temporal range: | |
|---|---|
| |
| "Florideae" from Ernst Haeckel's Kunstformen der Natur, 1904 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | Archaeplastida |
| Division: | Rhodophyta |
| Subdivision: | Eurhodophytina |
| Class: | Florideophyceae Cronquist, 1960[2] |
| Subgroups | |
Classification
There are various classification schemes; see red algae. One option is to use the following:
Subclass Hildenbrandiophycidae
Subclass Nemaliophycidae
Subclass Corallinophycidae
- Corallinales
- Corallinapetrales
- Rhodogorgonales
- Sporolithales
The subclass Corallinophycidae was introduced in 2007.[9]
Subclass Ahnfeltiophycidae
- Ahnfeltiales
- Pihiellales
Subclass Rhodymeniophycidae
- Bonnemaisoniales
- Ceramiales
- Gelidiales
- Gigartinales
- Gracilariales
- Halymeniales
- Nemastomatales
- Peyssonneliales
- Plocamiales
- Rhodymeniales
- Acrosymphytales
- Atractophorales
- Catenellopsidales
- Sebdeniales
According to molecular clock analysis, Florideophyceae diverged from other red algae about 943 (817–1,049) million years ago. It split into Hildenbrandiophycidae ca. 781 (681–879) mya, Nemaliophycidae ca. 661 (597–736) mya and Corallinophycidae ca. 579 (543–617) mya, and ca. 508 (442–580) mya the split between Ahnfeltiophycidae and Rhodymeniophycidae occurred.[1]