ALCOS OBJECTIVE 1

Diversity of Plants

Diversity of Plants

Kingdom plante consists of 10 divisions Anthocerophyta – Hornworts Bryophyta – Mosses Hepatophyta – Liverworts Lycophyta – Clubmosses and Spikemosses Pterophyta – Ferns and Horsetails Cycadophyta – Cycads Ginkgophyta – Ginkgo and Maidenhair Gnetophyta Coniferophyta – conifers Anthophyta – Flowering plants

Diversity of Plants

Bryophytes Nonvascular seedless

plants Small, grow near

water Dominant

gametophyte Originated 475 mya

Division Anthocerophyta Hornworts Sporophyte typically

5cm in height ~ 100 extant species

Phaeoceros laevis Anthoceros agrestis

Diversity of Plants

Diversity of Plants

Division Bryophyta Mosses Sporophyte typically

~15cm in height Form dense mats 15 000 extant species Found on every

continent except Antarctica

Pyrrhobryum spiniforme Sphagnum sp.

Diversity of Plants

Diversity of Plants

Division Hepatophyta Liverworts Sporophyte less than

5cm in height Typically found in

tropical or subtropical regions

~9000 extant species

Frullania ericoides Marchantia polymorpha

Diversity of Plants

Diversity of Plants

Seedless vascular plants Evolution of vascular

tissue Dominant sporophyte Originated 420 mya

Division Lycophyta Clubmosses and

Spikemosses ~1200 extant species Most primitive

vascular plants

Lycopodium tristachyum

Selaginella apoda

Diversity of Plants

Diversity of Plants

Division Pterophyta Ferns, Horsetails and

Wisk ferns 12 000 extant species Thrive in temperate

climates Dominated forest of

carboniferous period

Osmunda cinnamomeaPolystichum acrostichoides

Diversity of Plants

Cheilanthes alabamensis

Trichomanes petersii

Diversity of Plants

Psilotum nudum Equisetum hyemale

Diversity of Plants

Diversity of Plants

Vascular seed plants Evolution of seeds Dominant sporophyte Originated 360 mya

Division Cycadophyta Cycads ~100 extant species Grow exclusively in

tropical habitats Only species found

wild in U.S grows in Florida

Cycas circinalis Encephalartos sclavoi

Diversity of Plants

Diversity of Plants

Division Ginkgophyta 1 extant species Ginkgo biloba Cultivated trees Maidenhair tree Fan-like leaves turn

gold in autumn

Diversity of Plants

Division Gnetophyta Gnetophytes 75 extant species Most species found in

desert regions Some species may live

to be over 1000 years old

Ephedra torreyana Welwitschia Mirabilis

Diversity of Plants

Diversity of Plants

Division Coniferophyta Conifers 600 extant species Most are evergreen Adaptations for

conserving water

Pinus palustris Pinus taeda

Diversity of Plants

Taxodium distichum Juniperus virginiana

Diversity of Plants

Diversity of Plants

Division Anthophyta Flowering plants Subdivided into

Monocotyledons and Dicotyledons

Monocotyledons 65 000 extant species Grasses, orchids, lilies

and palms Dicotyledons

185 000 extant species Shrubs, trees, cacti,

wildflowers, garden flowers, vegetables and herbs

Digitaria sp. Andropogon glomeratus

Diversity of Plants

Hymenocallis coronaria Platanthera ciliaris

Diversity of Plants

Myrica cerifera Smilax laurifolia

Diversity of Plants

Acer rubrum Liquidambar styraciflua

Diversity of Plants

Quercus rubra Quercus alba

Diversity of Plants

Spigelia marilandica Mitchella repens

Diversity of Plants

Clitora mariana Trillium sp.

Diversity of Plants

Dichotomous Keys

Dichotomous Key Made up of set of numbered statements Each set deals with a single characteristic of the

organism Leaf shape or leaf arrangement Bark and twig structure Flower arrangement and structure

A key to the trees of Alabama http://www.aces.edu/pubs/docs/A/ANR-0509/ANR-0509.p

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