http://www.perspective.com/nature/plantae/

KINGDOM PLANTAE

Evolution• There are over 280,000 species of plants on

Earth. • They are estimated to have evolved from

green algae 450-630 million years ago.• The fist plants to evolve where similar to

mosses and reproduced using spores, an adaptation to being on land. • Over time, selection favored plants that

could tolerate dry land which lead to seed evolution. • Plants with true seeds evolved around 390-

320 million years ago.• As selection began to favor plants with

seeds a new adaptation was seen, flowers and fruits, around 130-200 million years ago. • Some flowering plants have adapted to live

back in the aquatic environment from wince they first evolved (aquatic angiosperms)

Life Cycle• Plants have a life cycle that consists of alternating phases. “Alternating of Generations”• Sporophyte (2N)• Gametophyte (1N)

• In seeded plants the

sporophyte is the most

dominant form. The

gametophytes are

structures on the

sporophyte. (Ex. flowers)

Classification

• Botany is the study of plants. • In botany, plants are classified into divisions instead of phyla. • The divisions are based on three factors:• Vascularization• Seed Production• Flowering

Embryophyta

LAND PLANTS

Embry0phytes• In general, land plants are:• autotrophs (photoautotrophs)• reproduce asexually and sexually• multicellular• Phototropic- grow toward light• cell walls made of cellulose

•The phyla of kingdom Plantae are divided into four major divisions…• Bryophyta • Pteridophyta• Gymnosperms• Angiosperms

Bryophyta (the mosses)• Non Vascular• Reproduce with Spores

• Includes the mosses, liverworts, and hornworts

Tracheophytes

VASCULAR PLANTS

Tracheophytes- Vascular plants

• Tracheophytes are land plants that have vascular tissue. They include all plants except for bryophytes. • Vascular tissue forms vessels that carry water, plant products and nutrients

up and down the plant.

• Xylem: Vessels that carry water and soil nutrients from the roots to the plant parts. (flows up!) They are always interior to the phloem.

• Phloem: Vessels that carry food (products of photosynthesis) form the leaves to the rest of the plant (flows down!) They are always exterior to the xylem.

• This allows them to grow taller/larger than non-vascular plants such as the bryophytes.

Pteridophyta (the ferns)• Vascular• Reproduce with Spores

• Clubmosses, horsetails, and ferns.

Spermatophytes

SEED PRODUCING PLANTS

Spermatophytes• Spermatophytes are plants that

reproduce with seeds instead of spores. • larger than spores.

• multicellular.

• produced by the fertilized gametes (ovules and pollen) of plants.

• germinate more easily than spores because they do not require much moisture.

• spread by the plant itself, animals, or the wind.

• can be naked or enclosed in the ovary of a flower/fruit.

• Two groups of seed producing plants angiosperms (enclosed) and gymnosperms (naked).

• http://news.nationalgeographic.com/news/2012/02/120221-oldest-seeds-regenerated-plants-science/

Gymnosperms (conifers)• Vascular• Sporophyte dominant life-cycle• Tend to be large and woody• Reproduce with Seeds• Includes conifers, cycads, Ginkgos, and Gnetales

Magnoliophyta

FLOWERING PLANTS

Flowers

• Stamen= male reproductive organ (pollen is released here)• Pistal= female reproductive organ (ovule is housed here)• http://www.mnh.si.edu/museum/news/firstflower/

Angiosperms (flowering plants)• Became the most dominant plant type about 60-100 million years ago. • The largest and most diverse division of plants. • Come in two basic types: monocots and dicots• Flowers are found on specialized stems called inflorescence. • Autotrophic• Vascular• Flowering/fruiting• Seed Reproduction

Heterotrophic Angiosperms• Carnivorous/insectivorous

Plants:• Heterotrophic adaptation

increases the growth and reproduction of the plant- most can grow strictly from autotrophic plant products but grow and reproduce better when heterotrophic.

• They capture prey and externally digest it, then absorb the nutrients.

• Parasitic and Saprophytic plants:• Heterotrophic- some are still

slightly autotrophic but some lack cholorphyll completely and are strictly heterotrophic

• Steal food, nutrients, and water from other plants

• Usually do not have roots

• Chemotrophic

Mimicry in Plants• There are many types of mimicry in the plant kingdom, most involve attracting a pollinator or avoiding a predator. • Plants have evolved that mimic the scents and appearances

of other plants and animals. • Mimicry gives them reproductive advantage. Those that

closely resemble the characteristic that is being mimicked will survive and reproduce better than those that do not. • http://labs.eeb.utoronto.ca/barrett/pdf/schb_54.pdf