Grass
is a type of
plant
with narrow leaves growing from the base. Their appearance as a common plant was in the mid-
Cretaceous
period. There are 12,000 species now.
[3]
A common kind of grass is used to cover the ground in places such as
lawns
and parks. Grass is usually the color
green
. That is because they are wind-pollinated rather than insect-pollinated, so they do not have to attract insects. Green is the best colour for
photosynthesis
.
Grasslands
such as
savannah
and
prairie
are where grasses are dominant. They cover 40.5% of the land area of the
Earth
, but not
Greenland
and
Antarctica
.
[4]
Grasses are
monocotyledon
herbaceous plants
. They include the "grass" of the
family
Poaceae
, which are called grass by ordinary people. This family is also called the Gramineae, and includes some of the
sedges
(
Cyperaceae
) and the
rushes
(
Juncaceae
).
[5]
These three families are not very closely related, though all of them belong to
clades
in the
order
Poales
. They are similar
adaptations
to a similar
life-style
.
With about 780
genera
and about 12,000 species,
[3]
the Poaceae is the fifth-largest plant family. Only the
Asteraceae
,
Orchidaceae
,
Fabaceae
and
Rubiaceae
have more species.
[6]
The true grasses include
cereals
,
bamboo
and the grasses of
lawns
(turf) and
grassland
. Uses for graminoids include
food
(as
grain
,
shoots
or
rhizomes
), drink (
beer
,
whisky
),
pasture
for
livestock
,
thatch
,
paper
,
fuel
,
clothing
,
insulation
,
construction
,
basket
weaving
and many others.
Many grasses are short, but some grasses can grow tall, such as
bamboo
. Plants from the grass family can grow in many places and make
grasslands
, including areas which are very dry or cold. There are several other plants that look similar to grass and are referred to as such, but are not members of the grass family. These plants include
rushes
,
reeds
,
papyrus
and
water chestnut
.
Seagrass
is a
monocot
in the
order
Alismatales
.
Grasses are an important food for many
animals
, such as
deer
,
buffalo
,
cattle
,
mice
,
grasshoppers
,
caterpillars
and many other
grazers
. Unlike other plants, grasses grow from the bottom, so when animals eat grass they usually do not destroy the part that grows.
[7]
This is part of the reason why the plants are so successful.
Without grass, more
soil
might wash away into
rivers
(
erosion
).
Grasses include some of the most versatile plant
life-forms
. They became widespread toward the end of the
Cretaceous
. Fossilized
dinosaur
dung (coprolites) have been found containing grass phytoliths (
silica
stones inside grass leaves).
[8]
Grasses have adapted to conditions in lush
rain forests
, dry
deserts
, cold mountains and even
intertidal
habitats
, and are now the most widespread plant type. Grass is a valuable source of food and energy for many animals.
[9]
Lawn grass is often planted on
sports
fields and in the area around a
building
. Sometimes
chemicals
and water is used to help lawns to grow.
People have used grasses for a long time. People eat parts of grasses.
Corn
,
wheat
,
barley
,
oats
,
rice
and
millet
are
cereals
, common grains whose seeds are used for food and to make
alcohol
such as beer.
Sugar comes from
sugar cane
, which is also a plant in the grass family. People have grown grasses as food for
farm animals
for about 4,000 years. People use bamboo to build houses, fences, furniture and other things. Grass plants can also be used as
fuel
, to cover
rooves
, and to
weave
baskets
.
In English, the word "grass" appears in several phrases. For example:
- "The grass is always greener on the other side" means "people are never happy with what they have and want something else".
- "Don't let the grass grow under your feet" means "Do something".
- "A
snake
in the grass" is about a person that will not be honest and will trick others.
- All flesh is grass
:
Old Testament
book of Isaiah
, chapter 40, verses 6?8. A very true observation of the present-day
ecology
. See the
Miocene
for the ecological relevance.
- Grass is a slang term for
cannabis
(pot, weed, or
marijuana
). Cannabis looks like a grass, but it is actually a
rosid
.