Chapter 29: Seedless Vascular Plants

Characterized by:

• life cycles with dominant sporophyte

• Vascular tissues (xylem and phloem)

• well-developed roots and leaves

Xylem

conducts most of the water and minerals

includes dead cells called tracheids

Phloem

consists of living cells and distributes sugars, amino acids, and other organic products

Lignin

found in vascular tissues

“Lignified”

provides structural support

Classification of Seedless Vascular Plants

Phylum Lycophyta (club mosses, spike mosses, quillworts)

Phylum Monilophyta (ferns, horsetails, whisk ferns)

Lycophytes (Phylum Lycophyta)

• many grown on tropical plants as substrate (not a parasite)

• forest floors

• underground

Selaginella moellendorffii

Lycophytes;

spike mosses

Isoetes gunnii

Lycophytes;

quillwort

Diphasiastrum tristachyum

Lycophytes;

clubmosses

Homosporous

Phylum Lycophyta; produce one type of spore

Ex: clubmosses

Heterosporous

Phylum Lycophyta; produce two different types of spores

Ex: quillwort and spikemoss

Monilophytes (Phylum Monilophyta)

ferns, horsetails, whisk ferns (and relatives)

Ferns

Monilophytes;

have megaphylls

horizontal stems with large leaves (fronds)

homosporous

Ex: Matteuccia struthiopteris (ostrich fern)

Horsetails

Monilophytes;

gritty texture

also called “arthrophytes”

stem = main photosynthetic organ

Ex: Equisetum telmateia (giant horsetail)

Whisk Ferns and Relatives

Monilophytes;

dichotomously branching stems but not roots

Ex: Psilotum nudum (whisk fern)