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

HepaticophytaLiverworts

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

BryophytaMosses

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 ManThis 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