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Biosphere Community

Plant Pages


Diversity of Plants: Major Groups

  Mosses, Liverworts & Hornworts
 
Ferns, Ground Pines & Horsetails
 
Seed Plants: Conifer Images
 
Flowering Plants: Angiosperms
 
Water Lilies
 
Monocotyledons
    Monocots: Grasses
   
Dicotyledons

 

 

 

 

 

 

 

 

 

Background

Plants eat sunlight. Along with algae and cyanobacteria in Earth's waters and on land, plants are the essential basis for all animal life, for plants (and these other photosynthesizers) create food energy using sunlight, water, and carbon dioxide. This process of photosynthesis was Earthlife's greatest invention, for it is the foundation on which virtually all other life rests.

Most plants nowadays are flowering plants (angiosperms), which include most trees, shrubs and herbs, grasses and flowers. Angiosperms are the most recently evolved kind of plant, and dominate terrestrial Earth. Other common groups of plants are conifers, ferns, and mosses.

Millions of years ago, enormous swamp-forests of tree-ferns and cycads were buried and gradually became the coal, oil and natural gas our civilization lives on today. We are living today on fossil sunlight energy captured by plants and stored by Earth a very long time ago.

The Tree of Life grows an incredible diversity of beings. About 350,000 species of plants are estimated to currently exist, including conifers, flowering plants, mosses & liverworts, and ferns & fern allies. Just under 300,000 plant species have been scientifically described, the vast majority being flowering plants. Once flowering plants (angiosperms) developed on Earth, there was an explosion of species, slow in our time-sense, very quickly in evolutionary time.


Diversity of Plants

Contemporary land plants are all multicellular eucaryotes. Most algae are unicellular, and are not presented here. For algae, go here. Almost all land plants feed themselves using photosynthesis; a few are parasitic on other plants, and at least one species is parasitic on a fungus. The cell walls of land plants are made of cellulose.Virtually all land plants have specialized organs, called leaves and leaflets, that carry chloroplasts. Chloroplasts are where photosynthesis takes place. The plant groups shown below are just the most important groups. They appear in the order of their appearance on Earth.

Mosses, Liverworts & Hornworts
(Bryophytes)

Bryophytes are the earliest multicellular plant pioneers. They first colonized land at the beginning of the Paleozoic Era, about 450 million years ago. Unlike most living plants, bryophytes have no interior vessels to transport water and nutrients. As a result, Bryophytes are small, soft, and most must be near moisture. All bryophytes can reproduce vegetatively, as well as sexually.

Dicranum moss of the North Woods
detail of moss stems and simple leaves
two mosses, showing differences in size
moss sporangia, elevated to catch wind
   
liverwort eking out a living in a quartz crevice
flat thallus liverwort of temperate climates
liverworts and mosses cohabit near a stream
Liverwort Marchantia sporangia

Young sporophyte generation of hornwort springs up from the basal gametophyte generation that they live upon. Photo credit Christine Cargill

a hornwort showing both the long-lived gametophyte generation and the sporophyte generation which gave them the name
"horn-plant" Photo credit David Weber

Pterodophytes: 20,000 species
Ferns, Ground Pines, and Horsetails

Ferns and their relatives are vascular plants; they have vessels inside their stems to transport water from roots to fronds, and nutrients from fronds to roots. They can reproduce both sexually, with spores, and vegetatively, from runners.
Pterodophytes emerged on Earth around 359 million years ago.
The three groups shown are ferns, ground pines or club mosses, and horsetails.


Ferns

maidenhair fern growing on rock face
ostrich fern fiddleheads unrolling
cinnamon fern frond unrolling
Japanese painted fern
cinnamon fern fiddleheads emerging from soil
epiphyte leathery polypody growing on Sitka spruce, showing red sori, each with hundreds of spores
mini-fern green spleenwort just emerging
cinnamon fern spores
Ostrich fern fronds
sensitive ferns splashed with light

Ground Pines (Club Mosses)

round branch ground pine, a club moss
ground cedar, a club moss

Horsetails, Equisetum
These early plants contain silica and have been used to
scour pots since the first pots were built.


the radial symmetry of horsetail leaf whorls
typical horsetail frond
horsetail spore-bearing strobilus
horsetail silica-bearing "scouring rush"


Seed Plants: Conifers
630 species

Conifers appeared on Earth some 300 million years ago. While there are a comparatively small number of species, conifers are ecologically central to life in the northern hemisphere; they dominate the great circumpolar forests of the taiga.

California coastal pine, probably Pinus contorta contorta
Bristlecone Pine @ 12,000', thousands of years old
bristley cone on Bristlecone Pine
cone of Ponderosa Pine, seeds dispersed
Ponderosa Pine seeds winged to spin away
conifer meadow, Mt. Shasta
bough of incense cedar
tender new growth on an ancient California Redwood tree
Utah Juniper
cones of Western Hemlock
Tamarack in autumn, a deciduous conifer
tops of mountan Sequoia
male cones of red pine, soon to release pollen
enormous base of mountain sequoia
new growth on Silver Fir @ 7,000'
gigantic trunk of California Coast Redwood
developing cone of Red Pine
young female cones of Red Pine

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Flowering Plants (Angiosperms)
Water Lilies, Monocots and Dicots



Water Lilies, a basal group of 80 species

yellow waterlily, also called spatterdock
white water lily
Monet
Nympheas by Claude Monet, ca 1915
A lilypad growing toward light
a mature spatterdock flower

 


Monocotyledons
50,000 to 60,000 species; important foods


arrowhead, aquatic Sagittaria
perfoliate bellwort, a woodland wildflower
Virginia bluebells, woodland wildflower
chiondoxa, cultivated spring bulb
turkscap lily, a fresh meadow wildflower
lily, coastal California
giant Solomon's seal, woodland wildflower
rose pogonia, a wild bog orchid,
like all orchids, a monocot
crocus, cultivated spring bulb
daylily, cultivated monocot
iris yellow flag, the original fleur de lis
chives, like entire onion family, monocot
Trillium, woodland wildflower
wild iris on marshland
wild lily of valley, emerging from soil

 


Monocots: Grasses
9,000-10,000 species; crucial crops

Seedhead of Big Bluestem of the tallgrass prairie
flowers of Big Bluestem of the tallgrass prairie
seed spike of timothy grass
typical panicle arrangement of seeds
flowers of Little Bluestem, native prairie grass
Indian rice grass seedheads, New Mexico desert
seedhead of rattlesnake grass, California
detail of anthers of big bluestem
inflorescence of a marsh grass
inflorescence of redtop grass
stems of wheat, oncea wild grass
diversity of Maize seedheads, once a wild grass


Dicots, most numerous plant group
175,000-200,000 species

 

Birdsfoot Trefoil, naturalized immigrant
Brown-eyed Susan, native wildflower
Sky Blue Asters in August, native wildflower
Prairie Clover, native wildflower
Teddybear Cholla cactus, Joshua Tree, CA
Red Barrel cactus, Joshua Tree, CA
wild Bottle Gentian, petals must be forced apart by bumblebees for pollination
wild Columbine in bud and flower
wildflower butterfly weed
daisy fleabane, with syrphid fly pollinator
hood of Darlingtonia Pitcher Plant, a carnivore & perch for a California Dancer damselfly

Indian Pipe, a parasite on mycorrhizal fungi

Rue Anemone, spring wildflower
Mountain Lupine, wildflower at altitude
Hepatica, spring wildflower
Milkweed, friend to Monarch Butterflies
Marsh Marigold, semi-aquatic wildflower
rabbitsfoot clover
Great Blue Lobelia, wildflower
waxy bells of Dogbane, wildflower
Skunk Cabbage flower inside its protective hood
Indian Paintbrush in Panther Meadow, Mt. Shasta, CA
maple leaves, deciduous native tree
unidentified seaside succulent in flower
Field Bindweed, native wild vine
honeysuckle vine
Tall Sunflower, native wildflower
Staghorn Sumac, woody native shrub
Thistle flowers, native wildflower
Wild Cherry tree in blossom

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Explore Further in Plant Pages

Plants: What's New? Including Symbiosis with Fungi and Bacteria
Plants: Major Kinds (Images)
Plant Defense including Symbiosis with Wasps
Plant Pollination including Symbiosis with
Insects, Mammals and Birds
Seed Dispersal Including 'Compelled Symbiosis' with Birds, Insects and Mammals

Explore Further in Biosphere

 
Biosphere: Introduction
 
Biosphere as Place: Introduction
 
Biosphere as Ocean: Life Zones
 
Biosphere as Ocean Floor: Benthic Biomes One
 
Biosphere as Ocean Floor: Benthic Biomes Two
 
Biosphere on Land: Terrestrial Biomes
 
Biosphere on Land: Anthropogenic Biomes
 
Biosphere as Process: Introduction
 
Biosphere Process: Floating Continents, Tectonic Plates
 
Biosphere Process: Photosynthesis
 
Biosphere Process: Life Helps Make Earth's Crust
 
Biosphere Process:
Rock Cycle--Marriage of Water and Rock
 
Biosphere Process: Marriage of Wind and Water
 
Biosphere as An Expression of Spirit
 
The Ecological Function of Art
 
The Earth Goddess
 
The Tree of Life
 
The Green Man
 
Earth Art
 
Biosphere as Community
 
  Biosphere Microcosm: Bacteria and Archaea
The Procaryote Domain
 
  Biosphere Microcosm: Germs
 
  Biosphere Community: The Eucaryote Domain
 
  Biosphere Community: Protists 1: Algae
 
  Biosphere Community: Protists 2: Protozoa
 
  Biosphere Community: Plants: What's New?
 
  Biosphere Community: Diversity of Plants--Major Groups
 
  Biosphere Community: Plant Defense
 
  Biosphere Community: Plant Pollination
    Biosphere Community: Plant Seed Dispersal
 
  Biosphere Community: Kingdom Animals
 
  Biosphere Community: Kingdom Fungi
 
  Biosphere Community: Six Great Extinctions
 
  Return to Ecology Index