Grass generally describes a monocotyledonous green plant characterized by slender leaves, called blades, which usually grow upwards from the ground. The family Poaceae (also known as Gramineae) is for flowering plants that are botanically regarded as true grasses. There are approximately 600 genera and 9,000 species of grass. [
] Grasses comprise about one-quarter of the world's vegetation.
Types of grass
There are many plants outside the Poaceae family that have similar appearances to grass, and are commonly called "grasses", or have "grass" as part of their name. These include
Cannabis, China grass, more commonly known as
Ramie (
Boehmeria nivea), a
nettle grown for
bast fibres, in the Family
Urticaceae, Ditch grass or Wigeon grass (
Ruppia maritima) in the Family
Ruppiaceae, Fish grass (
Cabomba caroliniana), a freshwater aquatic,
Goosegrass (
Galium aparine),
Mondo grass or Lily turf (
Ophiopogon japonicus), an Asian ornamental ground cover,
Nutgrass, a common lawn pest (
Cyperus rotundus) in the Family
Cyperaceae,
Pepper grasses (
Lipidium spp.) in the family
Brassicaceae,
Sawgrass, abundant in sub-tropical marshlands (
Cladium spp.) in the Family
Cyperaceae,
Scurvy-grass (
Cochlearia species) in the Family
Brassicaceae,
Scurvy-grass Sorrel (
Oxalis enneaphylla) in the Family
Oxalidaceae,
Seagrasses, including
Eel grass (
Zostera spp.),
"Sleeping grass" (
Mimosa pudica) a
legume (Family Fabaceae) and lawn weed and
Xyridaceae, known as the yellow-eyed grass family.
Structure and growth
The leaf is the most familiar part of a grass plant and is composed of two parts: the
leaf blade and the leaf
sheath. In grass plants, the leaf rolls itself around the
stem forming the leaf sheath. The leaves, stems, and
roots all originate from the growing point (crown) that pushes new leaves upwards as they are formed and grow. This growth habit is not used in other garden plants such as
tomatoes,
marigolds,
trees, and
shrubs. Instead with those instances, the outward growth extends from the tips of the
branches or
shoots. The location of the grass growing point near the base of the plant allows it to be mowed regularly and have continued growth.
Grass plants spread out from a parent plant, this is a common growth characteristic. Growth habit describes the type of shoot growth present in particular grass plants and is directly related to their ability to spread out from the parent plant and ultimately form a lawn. There are three general classifications of growth habit present in grasses: bunch-type, stoloniferous, and rhizomatous.
See also
Footnotes
References
- Chapman, G.P. and W.E. Peat. 1992. An Introduction to the Grasses. CAB Internat., Oxon, U.K.
- Cheplick, G.P. 1998. Population Biology of Grasses. Cambridge University Press, Cambridge.
- Milne, L. and M. Milne. 1967. Living Plants of the World. Chaticleer Press, N.Y.
- Soderstrom, T.R., K.W. Hilu, C.S. Campbell, and M.E. Barkworth, eds. 1987. Grass Systematics and Evolution. Smithsonian Institution Press, Washington, D.C.
- Went, Frits W. 1963. The Plants. Time-Life Books, N.Y.
External links
Grasses
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