seed-bearing plants fall into two major categories

Seed-bearing Plants fall into two major categories

Gymnosperms

Angiosperms

Seed-bearing Vascular Plants fall into two major categories

• Gymnosperms – seeds naked on surface of cone scale

• Angiosperms – seeds enclosed in a ripened ovary and flowers are produced

GYMNOSPERM CHARACTERISTICS

• From Greek words gymnos (naked) and sperma (seed)

• Both Male and Female cones

Land Plants

Bryophytes Pteridophytes

Bryophytes

Pteridophyte

Gymnosperms

Angiosperms

Flowers and Fruits

Vascular Tissue

Seeds

Seed-bearing plants also produce pollen

Five Living Seed Plant Phyla

• Cycadophyta

• Ginkgophyta

• Pinophyta or Coniferophyta

• Gnetophyta

• Anthophyta

Gymnosperms

Angiosperms

Living Gymnosperm Phyla

Cycadophyta - Cycads

Gnetophyta - Gnetophytes

Ginkgophyta - Ginkgos

Conifers - Pinophyta or Coniferophyta

Conifers – the most conspicuous and common gymnosperms

Conifers

About 70 genera with about 630 species

Conifers

• Conifers are well represented in the fossil record

Sequoia affinis

Conifers are of great ecological importance

• Conifers are the dominant members of the vast Boreal forests (Taiga)

Conifers are of great ecological importance

• Conifers are very important members of many types of ecosystems

Conifers are of great economic importance

• Edible Seeds• Crates, Boxes,

Matchsticks, Furniture

• Telephone Poles• Turpentine and

Rosin (Resin)• Fuel (Pitch)• Pulpwood• Ornamentals• Pharmaceuticals

(Taxol)

There are Seven Living Families of

Conifers

Pinaceae - Pine familyAraucariaceae - Araucaria familyPodocarpaceae - Yellow-wood familySciadopityaceae - Umbrella-pine familyCupressaceae - Cypress familyCephalotaxaceae - Plum-yew familyTaxaceae - Yew family

Five of the Most Familiar Groups of Conifers

Norfolk Island Pines

Junipers and Cedars

Yews

Sequoias and Redwoods

Pines, Firs, Spruces

The Largest, Tallest, and the Oldest Plants

are Conifers.All found in California• Giant Sequoias of the

California Sierras are the largest

• Coastal Redwoods are the tallest

• Bristlecone pines of the California White Mountains are the oldest

Pines - genus Pinus of the family Pinaceae

• Most familiar of all conifers

• About 90 species

Vegetative Characters of Pine

Pine Stems

• Extensive branching• Christmas tree shape• Very woody

Pine Leaves

• Needles produced in clusters (fascicles) of 1 to 5

Pine – Reproductive Structures

Pines produce pollen and seeds in cones

Pines are MoneciousIndividual plants produce both pollen cones and

seed cones

C

Seed Cone

Pines are MoneciousIndividual plants produce both pollen cones and seed

cones

C

Pollen Cone

Pollen cones produce pollen

C

Pine Pollen• Wind pollination is facilitated by

pollen morphology.

Ovulate or Seed Cones Produce Seeds

C

Young seed cone

Mature seed cone

Cone scale

Conifer Seed reminder

Bald Cypress

Juniper

Giant Sequoia

PineYew (aril)

Conifer Cones

Conifer Leaves

Map of Living and Fossil Members of Taxodiaceae (Redwood Family)

Dawn Redwood Metasequoia glyptostroboides and Coastal Redwood Sequoia sempervirens

Cycadophytathe Cycads

Cycads Appeared on Earth 250 MYA

• Greatest abundance and diversity during the Jurassic

• Declined sharply during the Cretaceous radiation of the angiosperms.

Cycad seeds are toxic to humans• Cyanobacteria in roots of cycads• Flying foxes eat neurotoxic cycad seeds• Humans eat the flying foxes• Humans get sick (neurological disorders)

Cycads

MexicanAustralian

African

Only Cycad Native to the US

Zamia integrifolia

Atala Butterfly

Cycads contain cycasin, a toxic secondary plant chemical. Cycads are toxic to humans, dogs and livestock. Cycasin is found in the atala butterfly and other organisms find it distasteful and avoid eating it.

Host Plant for

In Florida

Gymnosperms

Cycads

Ginkgos

Conifers

Bryophytes Pteridophytes