Tracheophytes

General InformationGeneral Information

Greek ‘trachea’ = windpipe, ‘phyta’ = plant).

Phylum Tracheaphyta. These are vascular plants.

Vascularization adaptation has allowed tracheophytes to become more fully terrestrial than bryophytes,

characterized by the presence of vascular tissue, composed of specialized conductive cells that create "tubes" through which materials can flow throughout the plant body

vascular tissues also provide a measure of support to the vascular tissues also provide a measure of support to the plant plant

The (2)The (2)two types of vascular tissuetwo types of vascular tissue

* xylem* xylem (dead cells) and (dead cells) and

* phloem* phloem (living cells) (living cells) the roots contain vascular bundles composed of the roots contain vascular bundles composed of

xylem and phloem.xylem and phloem. The roots The roots draw water and minerals from the soildraw water and minerals from the soil

and pass them upward to the stem and leaves.and pass them upward to the stem and leaves. They are also They are also responsible for storing the plant's responsible for storing the plant's

organic nutrientsorganic nutrients, which are passed downward , which are passed downward from the leaves through the phloem. from the leaves through the phloem.

Tracheophytes can be broken down into three classes: - Ferns- gymnosperms- angiosperms.

Fossils evidence suggests that some groups formed dominant flora in the past. Today ferns are prominent in some cool, moist areas.- direct descendants of earliest land plants; fossils of their relatives are 410 million years old (late Silurian period)- Terrestrial or epiphytic- instead of roots have rhizomes (underground stems with many rhizoids)- forked stems with very simple vascular tissue- spore cases form at tips of short branchs- only two genera known

Club mosses (e.g. Huperzia species)(previously known as Lycopodium species)- prostrate, branching stem with upright branches- simple vascular systems- spore-bearing leaves arranged in cones in some species- motile sperm (male gametes)                      

Ferns- rhizomes (underground stem), roots and leaves- vascular tissue grouped in strands (bundles)- leaves bear spores in sporangia- gametophyte is heart-shaped, small, green and completely independent- motile sperm

Vascular plants with seeds

Groups include:• primitive seeds ferns (now extict) - e.g. Glossopteris and Gangamopteris• flowering plants - monocotyledons and dicotyledons• cycads• Ginkgo biloba• conifers

Seed ferns (e.g. Glossopteris)

extinct, but many fossils found, particularly in the Permian coal measures of NSW and Qld- fern-like appearance

Cycads (e.g. Macrozamia various species)- separate male and female cones- motile sperm

Ginkgo biloba

- cultivated around Chinese and Japanese temples- once thought extinct in the wild but since discovered in remote regions of western China- fan-shaped leaves- separate male and female trees

- most have true cones- pollinated by wind- naked seeds - i.e. not surrounded by ovary wall- source of economically important timber - e.g. pine species, Western Red Cedar, Oregan and Australian native cypress pine

Conifers

Flowering plants (angiosperms)

- complex vascular tissue- dominate land vegetation except coniferous forests- great variation in form - shrubs, trees, climbers; woody and non-woody- structurally adapted to land habitats of great diversity, but also aquatic- pollinated by animals - e.g. insects, birds and mammals - as well as wind and water- flowers have stamens (male sex organs) and carpels (female sex organs)- seeds within a closed structure (fruit)- economically important

(e.g. grasses, palms)• have one seed leaf (cotyledon)• leaves narrow with parallel veins• vascular bundles scattered

Monocotyledons

(e.g. daisy, eucalypts)• have two seeds leaves (cotyledons)• marked netted veins• flower parts in fours or fives• vascular bundles arranged in cylinders

Dicotyledons

Fungi

Fungi lack chlorophyll and so are unable to make their own food. They are either saprophytes, which live off dead plants and

animals, or parasites, which live off plants and animals.

PLANT-RELATED ORGANISMS

Lichens are very unusual in that they are made of two organisms - an alga and a fungus - living together in a

mutually beneficial or symbiotic relationship. Lichens are the first conspicuous organisms to colonise bare rock

surfaces.

Lichens

Comparison of the three major groups of land plants:

Land plant divisions form three groups based on major morphological attributes:

•Bryophytes•Pteridophytes•seed plants

The characteristics of these groups are compared in the following chart.

Groups include:• fork ferns (Psilopsids)• club mosses (Lycopods)• horsetails• ferns