Prairie

Factors Maintaining Prairie

1. Low Rainfall

2. Fire

3. Grazing

• Each of these factors inhibits the growth of woody plants (trees and such) while favoring the growth of grasses and other herbaceous plants

Grasses in a Grassland

• Grass (Family Poaceae) are monocots and compose between 60% and 80% of plant species in a mature prairie habitats

• The three most common prairie grasses are:

1) Big Bluestem – Andropogon gerardi2) Indian Grass – Sorghastrum nutans3) Little Bluestem – Andropogon scoparius

Fire & Growth

Grass Adaptations: Moisture

• They reduce their surface area by having narrow leaf blades with parallel veins that allow the leaf to curl further reducing surface area in harsh weather

• They prevent excessive water loss by having a waxy cuticle covering the leaves, hairy stems reducing wind and evaporation from the surface, small recessed stomata, and the C4 photosynthetic pathway

• They are also known for having roots that make up at least ½ of the plant that may reach 6 or more feet into the soil

Grass Adaptations:Fire & Grazing

• The growth tissue in a grass (meristem) is located below ground and is able to generate new tissue after being burnt or eaten

• They take in and store silica (sand) in their tissue in and effort to wear down the teeth of grazers

• Their seeds are stimulated to germinate by chemical produced from burning

Grass Adaptations: Other

• They do not rely on animal pollinators to mediate sexual reproduction. Instead their pollen is transported by the wind, a reliable component of the prairie

• They often reproduce through asexual means, by modified stem called stolons or roots called rhizomes that radiate, touch the ground, and grow into a new plant

I think the prairies will die without grass finding a voice. Its democracy may be against it. Prairie grass never seems to know anybody.

William A. Quayle (1905) The Prairie & The Sea

Compared to trees, shrubs, or forbs, grasses seem unfathomably plain. They fail to inspire interest or stir the imagination. We look at prairie and we see a great emptiness, a void that staggers the psyche and leaves much too much for the mind to wonder.

Randy Winter (1987) Nature Notes

Every American has the right as part of his cultural heritage to stand in grass as high as his head in order to feel some small measure of history coursing his veins and personally establish an aesthetic bond with the past.

William E. Elder (1961) Needs & Problems of Grassland Presentation

Grass is the most widely distributed of all vegetable beings and is at once the type of our life and the emblem of our mortality…the carpet of the infant becomes the blanket of the dead.

John J. Ingalls (1872) In Praise of Blue Grass

Grasses are the greatest single source of wealth in the world.

Agnes Chase (1959) 1st Book of Grasses

The basis of human proliferation is not our own seed but the seed of grasses.

Evan Eisenberg (1989) Back to Eden

What a thousand acres of compass plant looked like when they tickled the bellies of the buffalo is a question never again to be answered, and perhaps not even asked.

Aldo Leopold (1949) A Sand County Almanac

Grass Roots & Stems

1. RootsFibrous and good as binding the soil

2. StemsFlowering stems or “Culms” are jointed with hollow internodes. A “Prophyllum” or modified first leaf of a branch that clasps the main culm, may support branching culms

Grass Leaves

Grass leaves haveparallel-veined blades

thatare usually narrow. A“Foliage” leaf has a“Sheath” that surroundsthe culm, a “Ligule” thatstands up at the junctionof the sheath and blade,and the leaf “Blade” itself

Grass Flowers

Grass flower clustersor inflorescences

bearScaly units calledspikelets that arearranged as a:

1. Spike2. Panicle3. Spikelike4. Raceme