Selected Plants of Navajo Rangelands

Take care of our Navajo Rangelands

Arrowgrass
Tł’ohk’aa’í
(a.k.a. seaside arrowgrass)

Streambank covered in arrowgrass

Arrowgrass is a wandlike, herbaceous wetland plant 12 to 40 inches tall with rhizomes. It is a grasslike plant in the Juncaginaceae family. Reproduction is from rhizomes and seed. Growth starts in early spring, and flowering occurs June through August. Flowers are green and spaced along a spikelike raceme. Fruits are almost cylindrical, up to ¼ inch long and fall from the plant at maturity. Leaves are linear, 3 to 8 inches long, narrow, and flattened or channeled.

Arrowgrass can be found in wet alkaline lowlands, and in meadows and swamps at elevations from 4,200 to 8,800 feet. It is occasionally confused with rushes because it occurs in habitats often dominated by them.

It contains hydrocyanic acid, especially when drought- or frost-stressed, which makes it highly toxic to livestock, even in amounts less than ¼ pound. It is a common component of wet meadows that are cut for hay. Arrowgrass in cured hay has been reported to cause poisoning in young animals.

*Description based on Utah State University Range Plants of Utah.

Botanical illustration showing plant parts of arrowgrass

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