''Eriochloa contracta'' is a species of

grass Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and spe ...

known by the common name prairie cupgrass. It is native to the central United States and it is

naturalized Naturalization (or naturalisation) is the legal act or process by which a non-national of a country acquires the nationality of that country after birth. The definition of naturalization by the International Organization for Migration of the ...

in areas to the east and west, where it is often a

weed A weed is a plant considered undesirable in a particular situation, growing where it conflicts with human preferences, needs, or goals.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. Pla ...

, especially in moist areas. This annual grass may grow up to a meter tall when erect or it may bend, rooting where nodes on the stem touch the ground. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is up to 20 centimeters long and is made up of several branches which stick out to the sides. The branches are lined with purplish spikelets a few millimeters long. Prairie cupgrass is one of a number of species that can cause

photosensitivity in humans Light sensitivity or photosensitivity refers to a notable or increased reactivity to light. Apart from vision, human beings have many physiological and psychological responses to light. In rare individuals an atypical response may result in seriou ...

References

External links

Jepson Manual TreatmentUSDA Plants ProfileGrass Manual TreatmentPhoto gallery
Panicoideae {{Panicoideae-stub