| Classification |
| Kingdom: Plantae
Division: Magnoliophyta
Class: Liliopsida
Order Type: Basal Angiosperms-Monocots
Order: Poales
Family: Poaceae
Family Common Name: Grass Family
Genera: Calamagrostis, Cortaderia, Deschampsis, Festuca, Miscanthus,
Panicum, Pennisetum, Zea |
Defining Features: The Poaceae
(or Gramineae) has been classified by their spikelet characters, but this
has changed at present to a focus on different micro and macro anatomical
features, so the arrangement within the family is still somewhat undefined.
The distinctive floral anatomy results in a specialized terminology. Ovaries
are superior with subapical to nearly basal placentation.
Defining Morphology: Floral
Features: Flowers are zygomorphic and bisexual or unisexual, monoecious
or dioecious. Perianth may be lacking. Inflorescence is of spikelets, which
are then arranged into panicles, racemes or spikes. Each spikelet is subtended
by 2 (or 0-7) glumes (or bractlets). The florets (flowers) are each enclosed
by two bractlets termed the lemma and palea. The bractlets sometimes produce
a stiff bristle termed an awn. If a floret has a perianth, it is modified
as two fleshy lodicules. Fruit and Seed Features: Monocotyledon. Fruit
is a caryopsis or grain with the lemma and palea persistent. Seeds are
fused to the pericarp and with endosperm present. Placentation is basal.
Vegetative Features: Habit as herbs or rarely woody shrubs or trees. Leaves
are simple, linear, narrow and alternate or basal in two ranks (or rows).
Bases are sheathed with open, overlapping margins. Auricles and/or ligules
are present where the stem, leaf blade and sheath meet. Venation mostly
parallel, but net-like in the forest-dwelling basal grasses and bamboo
relatives. Stems are round. Internodes are usually hollow.
Distribution: Widespread in
all climates and regions. Grasslands made up of species in the Poaceae
make up almost 25% of the world's vegetation cover.
Economic Use: The most important
plant family to humans, the Poaceae is the source of all the cereal crops
cultivated throughout the world, such as; wheat, rice, maize (corn), oats,
barley, millet, rye, sugar cane and sorghum. The grasses are also significant
as grazing crops and some as garden or indoor ornamentals. As building
materials and a source for matting, the bamboos are highly valued in Asia.
Number of Genera Globally: 650
Number of Species Globally: 9,700
