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Statewide IPM Program, University of California

Fivehook bassia  (Bassia hyssopifolia)

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Life stages of Fivehook bassia flowers mature plant seedlings foliage seeds

Fivehook bassia, a summer annual broadleaf, is an important weed found most frequently on saline soils. It germinates in early spring and the plant matures in late summer. It is found throughout California except the northwestern region and high elevations in the Sierra Nevada up to 4000 feet (1200 m) elevation. Fivehook bassia inhabits agricultural land (especially newly cultivated cropland) and disturbed and moist places. Although considered to be fair sheep forage, its leaves have varying amounts of potassium oxalate and can be fatal to livestock when large amounts are consumed.

Habitat

Roadsides, disturbed places, crop fields, ditchbanks, and seasonal wetlands.

Seedling

Fivehook bassia seedlings are indistinguishable from Kochia seedlings. Both have linear to narrowly lance-shaped, gray-green cotyledons (seed leaves) with soft white hairs. Subsequent leaves are narrowly lance shaped and similar in size to the cotyledons.

Young plant

Leaves on very young plants form a rosette.

Mature plant

The mature plant can reach 4 feet (1.2 m) tall. Several stems branch from the main stem, however, fivehook bassia it is not as branched as another member of the family, Russian thistle. Leaves are linear-lance shaped to lance shaped, slender, generally gray green, and flat. They mostly are alternate to one another along the stem and are covered with soft hairs. Fivehook bassia is hairier than kochia. 

Flowers

Flowers bloom from July through October. Flowering stems form spike flower heads along which inconspicuous flowers develop in clusters at the bases of leaf stalks and at the ends of the stems. Individual flowers do not have petals, but they have outer lobes that are densely covered with tan to golden, soft, furry hairs. A yellowish, tiny, hooked or curved spine is attached to the back of each lobe.

Fruits

Fruits remain enclosed within the dried flower. They are thin walled and have five, hooked spine lobes (one hook attached to each lobe).

Seed

There is one seed per fruit. Seeds are egg shaped and about 1/25 to 2/25 of an inch (1–2 mm) long.

Related or similar plants

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