3 Divisions of Non-vascular Non-seed plants Scientific Names Hepaticophyta Anthocerophyta Bryophyta Common Names Liverworts Hornworts Mosses

Evolution of Plants – We’ll start at the beginning with the non-vascular plants.

Why move to land? More CO2 More sunlight No pathogens (diseases) No predators (no herbivores – they didn’t exist yet!) Nutrient rich soil

Common characteristics among non-vascular non-seed plants Small No true organs (stems, roots, leaves) because they have no vascular tissue Stomata (pores where H2O is lost) are always open Must have H2O for reproduction The gametophyte generation is dominant

Hepaticophyta Liverworts Ancestors of all plants May be thallose (lobed leaves) or leafy (thin leaves Rhizoids anchor them to the ground.

Liverwort sporophyte

Liverwort sporophyte growing out of the gametophyte

Gemmae on a thallose liverwort– a means of asexual reproduction.

Leafy liverwort

Bryophyta Mosses The most diverse division of the 3. Have elongated cells to conduct H2O Rhizoids to anchor Some can live in deserts, others submerged in H2O

Reproductive life cycle of Mosses

Moss sporophytes growing out of the moss gametophyte

Moss sporophyte

Another moss

Cutting peat in a peat bog

The Bog Man This man died approximately 2000 years ago and was preserved in a peat bog. Because the bog is extremely acidic and contains very little oxygen it prevents the microorganisms that cause decay from developing.

Anthocerophyta Hornworts Cells usually contain one chloroplast Many work together with nitrogen fixing bacteria Sporophyte is similar to vascular plants