FAMILY POACEAE (GRASS FAMILY)
•
•
•
•
•
•
•
•
•
Cereals and Grasses (25% of vegetation)
600 genera and 8,500 species
Wheat (Triticum vulgare)
Rice (Oryza sativa)
Barley (Hordeum vulgare)
Oat (Avena sativa)
Millet (Pennisetum americanum)
Summer grass (Cynadon dactylon)
Winter grass (Poa annua)
Ornithopoda Varigata Chasmanthium latifolium
ORNAMENTAL GRASSES
Meadow Grass
Sisyrinchium mucronatum
•
•
•
•
•
•
•
Monocots
No Secondary Growth
Herbaceous plants
Parallel Venation
Base of each leaf forms a sheath
Stems (culms) hollow, unbranched
Both annual and perennial species occur
• Source of Gluten
(gliadin and glutelin)
• Endosperm of grasses
• Elasticity of dough
• Due to fermentation by yeast, CO2 trapped
• Leavened Bread
• High gluten in wheat and rye responsible for
Leavened bread
FLOWER
• Small, inconspicuous and incomplete
• Sepals and petals replaced with
lodicules
• Three stamens and one carpel
• Ovary single but two styles and stigmas
• Stigma enlarged and feathery
• Stamen pendant
• Wind-pollination
GRASS FLOWER
WHEAT
• Widely cultivated cereal
• Wheat-producing countries
Ukraine, U.S, Canada, China, India,
Argentina, France, South Africa
• Modern Cultivars durum, bread wheat
• Durum wheat (Triticum durum) grown in
Northern United States, Canada, Europe
Durum wheat
• T.durum high gluten content and yields
semolina flour (used as spaghetti, macaroni,
and noodles)
• Triticum aestivum (Bread wheat) makes 90%
of world production
• Used in breakfast, bread, pastries
• New cultivars constantly being developed
•
•
•
•
Vitamin A,
B12,
C
iodine missing
• Refined wheat flour mixed with wheat
• Riboflavin
• Niacin
• Thiamin
CORN
•
•
•
•
•
•
•
Zea mays (maize) summer annual crop
Corn in U.S
In England Corn refers to wheat
In Scotland corn refers to oat
Amylose and Amylopectin
Large chromosome (Barbara McClintok)
Popcorn, Flint, Flour, Dent, Sweet, Waxy
and Pod
• Sweet corn contains high concentration of
sugar instead of starch
• Waxy corn relatively new, appeared in China
• introduced into U.S (glossy, wax-like
appearance)
• Source of carbohydrate, fats and proteins
• Corn starch, corn oil, corn syrup all processed
from corn
• Used as biofuel
• Color depends upon pigmentation of
endosperm, aleurone layer and pericarp)
Waxy Corn
(Amylopectin in
Endosperm)
Pop Corn (Hard
kernels with hard
starch (more
amylose)
surrounding a core
of soft starch and
endosperms with
water
Dent Corn (Successful with hard and soft
starch, hard starch along sides and soft to
top and centre
Flint Corn (Hard starch in
outer part of kernel)
Sweet Corn (High concentration of sugar
instead of starch in cells of endosperm)
Flour Corn
Cross section Maize stem
RICE
• Only crop grown extensively for human
• More than 2 billion people in Asia rely on rice
as dietary staple
• Oryza sativa main cultivated rice
• 20 species in this genus known
• Cultivated in flooded fields, and paddies
• Azolla weed useful for rice (symbiosis)