Charophyceans

Supergroup: ArchaeplastidaEukaryoteMulticellularPhotoautotrophs

Charophyceans

Miscellaneous Info:- Obligate aquatic algae- Grow in calcareous fresh water- Live around the world, in tropics to cold temperate zones

Cell Structure- small, disk-like chloroplasts- sometimes multinucleate- cellulose cell walls, starch serves as storage material

Bulbils: Special storage structures accumulated by starch, consist of rounded cells of different sizes that grow in clusters on the lower stem and root nodes

Sexual ReproductionHighly specialized reproductive organsFemale: large oval structure with spirally arranged envelope, bright green filaments of cells, called oogoniumMale: large, bright yellow or red, spherical, called antheridiumFertilization forms a protonema, where a sexually reproducing algae develops

Green algae, closest algal relatives of land plantsSpecial Cell Feature:Rosette cellulose-synthesizing complexes (rose-shaped arrays of proteins that form cell wall cellulose)- this is one reason why we know they shared a common ancestor with land plants

Interesting Facts:- Found in inner reaches of the Baltic Sea and tropical brackish lagoons, but not marine environments- water must be slow flowing with little pollution

Common characteristics with land plants:- Rosette cellulose-synthesizing complexes- Peroxisome enzymes (limits losses during photorespiration)- Flagellated sperm- Formation of cell plate

Examples:Charales- informative fossil record, over 420 million years longZygnematales- are important to algal scum on plants ' rocks