How to Manage Pests

Identification: Weed Photo Gallery

Blunt spikerush

Scientific name: Eleocharis obtusa (Sedge Family: Cyperaceae)

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Blunt spikerush, a common annual sedge, may be found on poorly drained soil, levees, in shallow ditches and marshy areas. In California, it is mostly inhabits marshes and the edges of ponds and lakes in the northwestern region, Sierra Nevada, and Modoc Plateau to about 8500 feet (2600 m). Although seldom weedy in rice fields, it sometimes grows in irrigation canals associated with the crop. In natural areas it is a desirable component of the vegetation.

Seedling

Seedlings are grasslike with triangular stems.

Mature plant

Mature blunt spikerush grows from 4 to 20 inches (10–50 cm) tall and has round, bladeless stems. It is characterized by a lack of underground, horizontal creeping stems (rhizomes) and its unique flower head and fruit.

Flower

Stems do not have leaf blades. They terminate in a small, brown, densely egg-shaped or oblong flowering head with a rounded tip.

Fruit

Fruit are somewhat egg shaped, roughly 1/25 to 1/17 of an inch (1–1.5 mm) long, pale brown and shiny.

Reproduction

Primarily by seed.

More information

• Sedge ID illustration
• Calflora's distribution map
• See UC IPM's Pest Management Guidelines for agricultural information