1. Seedless Vascular Plants

2. Seedless Vascular
Recall: Bryophytes have only one way to transport water Osmosis
This fact limits their height
New plants evolved from these Bryophytes with a detailed transport system---Vascular tissue
Specialized cells that conduct water and nutrients throughout the plant

3. Evolution of Vascular Tissue
Tracheids: Hollow plant cell in xylem tissue with thick cell walls that resist pressure
Great evolutionary innovation of plant kingdom
Why?

4. Xylem and Phloem 2 Types of Vascular Tissue
Xylem: a transport subsystem that carries water upward from the roots to every part of a plant
Phloem: a transport subsystem that transports solutions of nutrients and carbohydrates produced in photosynthesis

5. Xylem and Phloem
Both can move fluids through the plant against gravity
Due to the thick walls of xylem and lignin, a substance that makes cell walls rigid, plants were able to grow taller and more upright.

6. Xylem and Phloem

7. Ferns and Their Relatives
Seedless vascular plants include club mosses, horsetails, and ferns
Vascular plants have TRUE roots, leaves and stems
Roots: underground organs that absorb water and minerals
Leaves: photosynthetic organs that contain one or more bundles of vascular tissues
Stems: supporting structures that connect roots and leaves

8. Club Mosses Most club mosses produced the first forests on Earth
These exist today in huge beds of coal
Today club mosses are small plants that live in moist woodlands

9. Horsetails Plant that typically grows 1 meter tall
Scale-like leaves are non-photosynthetic
Called horsetails because its stems look similar to horses tails and contain crystals of abrasive silica
Used in ancient times to scour pots and pans

10. Ferns Evolved about 350 million years ago
11,000 species of ferns are living today
Ferns have vascular tissue, strong roots, creeping or underground stems called rhizomes, and large leaves called fronds
Ferns are most abundant in wet habitats and need little light to survive

11. Ferns

12. Life Cycle of Ferns
Ferns and other vascular plants have life cycles in which the diploid sporophyte is the dominant stage
Fern sporophytes develop haploid spores on the underside of their fronds in tiny containers called sporangia