SWES 475/575 Class Notes – Tuesday, February 10, 2004

Green Algae III & IV– Chapter 19 & 21

Chapter 19 – Trebouxiophyceans

Phycobionts – lichen algae

Harold Bold – popularized algae as food

"Soylent Green" movie with Charleton Heston

Can be phycobiont w/ sponges

Chapter 21 – Charophyceans

Ancestor of land plants – 470 million yrs ago

Single-celled desmids (Zygnematales) to filaments (Charales) to macrophytes (Coleochaetales) to land plants

Have mitotic division like land plants

desmids

lakes, ponds, ditches, streams

conjugation tubes for reproduction – fusion to zygote, gametes

Covered with mucous secreted from inside

Ecology- freshwater habitats, ubiquitous

not too conspicuous

Mainly filaments on pseudoparenchymatous

plasmodesmata – transfer nutrients (starch, lipids)

meiosis, mitosis, 8-12 haploid products

nuisance weeds – good aquatic habitat, thallus up to 2 meters

food for waterfowl, common in Central Arizona Project canals

very branched filaments

multi-celled

colorless rhizoids

antheridia (male) oogonium like land plants