Diversity of Plants (Lecture)

Taxonomy

Phylogeny

Evolution

What does the field of systematics comprise of?

Taxonomy

Identification, nomenclature, and classification

Phylogeny

Relationships of taxa and the “pattern” of evolution

Biosystematics

The “process” of evolution

-phyta

Suffix for Phylum

-opsida

Suffix for Class

-ales

Suffix for Order

-aceae

Suffix for Family

-oideae

Suffix for Subfamily

-eae

Suffix for Tribe

10 ecoregions

How many ecoregions is Texas generally divided into?

Identify and name species

Classify

What are the two main goals of Taxonomy?

Holotype

The particular specimen designated by the author, which automatically fixes the application of the name.

Lectotype

Chosen later from the original material when no holotype was designated.

Neotype

Chosen from non-original material when all original material is lost or destroyed.

Syntype

Two or more specimens cited in the original description when no holotype was designated.

Paratype

Additional specimens cited in the original description, but not the holotype.

Bryophytes

Seed-free Non-vascular plants that reproduce by spores with a gametophyte-dominant life cycle. They have Rhizoids instead of true roots and require free water for fertilization.

~445 Ma

When was the Late Ordovician?

Cryptospores

The earliest evidence of land plants, wind-dispersed spores with tough walls.

Sporopollenin

A very tough biological polymer that makes up the major part of the outer exine walls of plant spores and pollen grains. This is the most resilient biopolymer in nature.

1. Overcome reliance on water for reproduction.

2. Prevent desiccation.

3. Conduct water and nutrients.

4. Support and structure.

5. Anchor and absorb.

Challenges of life on land

Tracheids

Water-conducting cell in the xylem

Embryophyta

Land plants that evolved from aquatic green algae, especially Charophyte algae.

Archegonium

Where the egg is at in Bryophytes.

1. Marchantiophyta (liverworts)

2. Bryophyta (mosses)

3. Anthocerotophyta (hornworts)

The 3 phyla within Bryophytes

Liverworts

Marchantiophyta, 90 families w/6000-9000 species

Mosses

Bryophyta, 120-130 familes, 12,000+ species

Hornworts

Anthocerotophyta, 5-6 familes, <300 species