The amazing grasses Flashcards
How much of the earth’s land surface is covered by grassland?
~25% of land surface, depending on definition.
What are the environmental characteristics of grasslands?
Habitat too dry to form forest but wet enough to not be desert. Usually have drastic wet/dry seasons.
How fast can the fastest-growing grasses grow? How tall can they become?
Can grow up to a half-meter per day up to 3 meters tall.
How much of grassland foliage is made up of grasses?
~80%.
What are some of the world’s major grasslands?
The Eurasian steppes, Mongolian steppes, Pampas, Serengeti, etc.
How much of the original North American prairie still exists?
~1% of the original prairie, the rest has been converted to agricultural use.
How many species are in the grass family (Poaceae)?
> 11,000 species in 759 genera.
How much of the calories consumed by the world population come from cereals?
~50%.
What is the fruit of the grass family? Describe its characteristics.
The grain, a dry indehiscent single seed which stores starch and protein.
How many years ago did grass cultivation likely start?
~14,500 years ago.
Of the many hundreds of grasses, how many were domesticated?
Only 34!
Where in the world is it suggested that agriculture first began?
The “fertile crescent” in the Middle East.
What are some traits which we’ve selected for when domesticating grasses?
Large seeds, flavour, non-shattering influorescences, annual life-cycle, etc.
What are the 3 most extensively grown food crops?
- Corn
- Wheat
- Rice
Where was corn domesticated? How many years ago? Where does its wild ancestor grow?
Domesticated in Mexico 5000-3400 years ago. No living wild ancestor exists.
How much of cultivated corn is actually used for food products?
<3%.
Where was rice domesticated? How many years ago? How does it grow in the water without drowning?
Originated in China and India ~11,500 years ago. Has air chambers in the stem to bring air to the roots.
How does starch composition affect the characteristics of rice?
Varies the stickiness of the food product.
Where was wheat domesticated? How many years ago?
Domesticated in the Middle East ~9000 years ago.
How many species of bamboo are there?
~1000 species in 90 genera.
How tall can bamboo grow up to? How much can it grow in a single day?
Can grow up to 40m, 60-90cm per day.
What term is used to describe the hollow jointed stem of a bamboo stalk?
A culm.
What important fiber is present in bamboo plants?
Lignin.
How has bamboo been used by humans?
In structures, tools, boats, containers, etc.
