Kingdom Plantae Gymnosperms Gymnosperms Phylum Cycadophyta cycads Phylum

Kingdom Plantae: Gymnosperms

Gymnosperms • • Phylum Cycadophyta (cycads) Phylum Coniferophyta (conifers) Phylum Ginkgophyta (gingko) Phylum Gnetophyta (gnetophytes)

Phylum Cycadophyta (cycads) • Small (about 200 species) • Mainly tropical – 1 U. S. species: found in Florida (Zamia pumila)

Phylum Cycadophyta (cycads) • Sporophyte features: – Trunk woody – Leaves often spiny and pinnately compound (divided into thin sections: feather-like). Note woody trunk Pinnately compound leaf

Phylum Cycadophyta (cycads) • Sporophyte features: – Pollen made in pollen cones Encephalartos pollen cones

Phylum Cycadophyta (cycads) • Sporophyte features: – Seeds made in seed cones Encephalartos female cone Megasporophylls of Cycas Ovule-bearing leaf (megasporophyll) of cone

Phylum Cycadophyta (cycads) • Sporophyte features: – Plants dioecious: separate male and female individuals. Cycas revoluta female Cycas revoluta male

Phylum Cycadophyta (cycads) • Importance: – Some used horticulturally: Cycas revoluta (sago palm)

Phylum Cycadophyta (cycads) • Importance: – Some are endangered in the wild – Example: South Africa has 40 species, all endangered

Phylum Cycadophyta (cycads) • Importance: – Since 1965, must have permit to own cycad in South Africa – One species extinct in wild. All plants left are males in gardens! Propagated by suckers (side branches). Encephalartos woodii, known only from male plants

Phylum Cycadophyta (cycads) • Importance: – Was a dominant land plant group during dinosaur era (Mesozoic Era).

Phylum Coniferophyta (conifers) • Largest gymnosperm group: 600 species • Dominates biomes in far north and south temperate zones • Many species with narrow leaves (needle-leaved trees) • Examples: Pines (Pinus), Junipers (Juniperus), Firs (Abies), Cypresses (Taxodium)

Phylum Coniferophyta (conifers) • Importance: – Also dominant group during Mesozoic Era (dinosaur time!)

Extinct Conifers • Example, Petrified Forest National Park, Arizona • Most trees there are extinct conifers whose trunks are mineralized.

Phylum Coniferophyta (conifers) • Importance: – Conifer forest biome (covers large part of Earth’s landmass) Conifer forests occupy high mountains in North America Temperate rain forest in Washington/Alaska

Phylum Coniferophyta (conifers) • Importance: – Currently dominant in parts of North (and South) Temperate Zones Light green is taiga or boreal forest (conifers)

Phylum Coniferophyta (conifers) • Importance: – Some communities in southeast dominated by conifers – Example, cypress (Taxodium) swamps Cypress branch Cypress swamp near Monroeville AL

Phylum Coniferophyta (conifers) • Importance: – Some communities in southeast dominated by conifers – Example, cypress (Taxodium) swamps BIOL 6140 (Plant Ecology) classes explore swamps on field trips

Phylum Coniferophyta (conifers) • Importance: – Biological records (largest tree) – Sequoiadendron gigantea (big tree) – In Sequoia National Park, CA – Base: 102 feet circumference – Weight: 2, 145 tons – Volume: 52, 500 cubic feet.

Phylum Coniferophyta (conifers) • Importance: – Sequoiadendron gigantea (big tree)

Phylum Coniferophyta (conifers) • Importance: – Biological records (oldest tree) – Bristlecone Pine (Pinus longaeva). Found in high mountains of deserts of California, Nevada, Utah, Colorado, etc.

Phylum Coniferophyta (conifers) • Importance: – Oldest tree was 4, 950 years. Cut down in 1964 by graduate student who got corer stuck in tree (U. S. Forest Service gave permission!) – Now oldest known bristlecone (named Methuselah) is 4, 767 years old. Location kept secret from public!

Phylum Coniferophyta (conifers) • Importance: – Biological records (tallest living tree) – Coast redwood (Sequoia sempervirens) – Grow on coast of California/Oregon (ex, Redwood National Park) – 96% have been logged

Phylum Coniferophyta (conifers) • Importance: – Biological records (tallest living tree) – Coast redwood (Sequoia sempervirens) – Tallest tree is 368 feet tall!.

Phylum Coniferophyta (conifers) • Importance: – Biological records (smallest trees? ) – Pygmy forest in Mendocino County, CA

Phylum Coniferophyta (conifers) • Importance: – Biological records (smallest trees? ) – Pygmy forest in Mendocino County, CA – Hardpan (like cement) forms at about 1 foot depth – Dry in summer, floods in winter.

Phylum Coniferophyta (conifers) • Importance: – Stress makes conifers (a pine and a cypress species) stunted The trees on the right had about 30 rings (30 yr old!)

Phylum Coniferophyta (conifers) • Conifers in Southern Hemisphere too • Example, Wollemi “Pine” (Australia) • Thought extinct, small stand found in in 1994. 40 plants! Discoverer David Noble

Conifers: Economic Importance – Harvest for pulp and timber – Can cause controversy, especially when old-growth and clearcuts involved.

Conifers: Economic Importance – Importance in Alabama: forestry #1 legal agricultural crop – Many pine plantations in southeast.

Conifers: Economic Importance – Edible (pine “nuts” are pine seeds) – Harvested from several species, including pinyon pine from western U. S. (shown below). Pinyon pine Pine seeds

Conifers: Economic Importance – Medicines: example, taxol – Antitumor agent. First extracted from bark of Pacific Yew (Taxus) tree – Now made synthetically. Pacific Yew, showing needles and bark

Phylum Coniferophyta (conifers) • Importance: – Threatened by humans (acid rain and forest decline) – Acid rain areas (below) include some conifer forests.

Phylum Coniferophyta (conifers) • Importance: – Acid rain and others stresses cause “forest decline”, weakness and death of conifer trees – Seen in N. Europe and N. America. Damage/death of fir trees in Tennessee

Phylum Ginkgophyta (Ginkgo) • Tiny group (1 living species: Ginkgo biloba) • Also called maidenhair tree

Phylum Ginkgophyta (Ginkgo) • Living fossil: Leaf fossils 150 million years old Photo of modern and fossil Gingko leaves

Phylum Ginkgophyta (Ginkgo) • May be oldest living species on Earth! Dinosaurs under a Ginkgo tree in the Mesozoic fall

Phylum Ginkgophyta (Ginkgo) • Today considered extinct in wild • Ancient trees (to 3, 000 years old!) found in China & Japan, in temple gardens and places tended by people. Ancient temple tree in China

Phylum Ginkgophyta (Ginkgo) • Leaves winter deciduous, fan-shaped, with dichotomously-branching veins • Made on stubby “short shoots” on branches Short shoots with leaf scars

Phylum Ginkgophyta (Ginkgo) • Gingko very useful horticultural tree • Pollution resistant, makes beautiful street tree A very old bonsai Ginkgo in fall on Japanese street

Phylum Ginkgophyta (Gingko) • A-bomb resistant! • This tree in Hiroshima, Japan, was 1. 1 km from where the first Atomic bomb was used in 1945.

Phylum Ginkgophyta (Gingko) • Medical uses: • May improve circulation, memory • Still under study • Pills of leaf extract worth millions of $/yr. Ginkgo farm (top) and drying leaves (bottom)

Phylum Gnetophyta (gnetophytes) • Small group (70 species) • Only gymnosperms with vessels in xylem (large, dead water-conducting cells)

Phylum Gnetophyta (gnetophytes) • Three genera (2 mentioned here): – Welwitschia from Namib desert (Africa) – Odd, only 2 leaves! Young plant grown in pipe section (long taproot) Old plant in Namib desert

Phylum Gnetophyta (gnetophytes) • Three genera (2 mentioned here): – Ephedra from many deserts of world Shrub is mostly branches (ovules seen on right

Phylum Gnetophyta (gnetophytes) • Three genera (2 mentioned here): – This shrub was original source of drug ephedrine – Used as stimulant, weight loss aid, may have side effects (stroke, etc. ). You can also find lawyers to help you sue the makers of ephedrine pills! You can buy ephedrine on the internet