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Weed Identification

poorland flatsedge

Family

Cyperaceae

Scientific Name

Cyperus compressus

Habit

Annual sedge is a weed of container ornamentals, nurseries, landscapes, and turf. It typically occurs in areas of frequent irrigation or low-lying poorly-drained sites.

Leaves

Leaves of annual sedge are light green, shiny, linear in outline but tapering to a point, and three-ranked. Individual leaves may be from 3 to 8 mm wide. Plants range from 4 to 18 inches tall and leaves are shorter or equal in length to the flowering stems. Leaves arise from the plant base. When crushed, leaves emit a sweet fragrance. No ligules or auricles occur, as would be the case with most grass seedlings.

Identifying Characteristics

Annual sedge is one of several types of sedge that are found in turf. Annual sedge differs from many of the perennial sedges in that it lacks rhizomes and tupers in the fibrous root system. Annual sedge is also much shorter than purple or yellow nutsedge and the leaf blades are narrower.

Flower Seed Head

Terminal seedheads occur at the ends of the triangular stems of annual sedge. Seedheads are typically less than 10 inches but may reach 18 inches.Three to ten short spikelets are found in a dense cluster at the tip of each stem.

Seed Fruit

Seeds of annual sedge are dull brown three-angled achenes.

Where Found

Annual sedge is found in most of the US and often infests irrigated lawns or low-lying wet areas.

Leaf Hair on Upper Surface

no hairs

Leaf Arrangement

rolled in bud

Mature Leaf Width

Varies: 
less than 5 mm
6 to 15 mm

Stem

triangle

Seedhead

multiple spikes

Life Cycle

summer annual

Auricle

not present

Ligule

none

Ligule Length

none

Plant Type

Sedge