Selected Plants of Navajo Rangelands

Diné bikéyah Chi’l nooséłígíí Bąąhą́ą́nosin
Take care of our Navajo Rangelands

St. Johnswort
Biłhaazhch’ih

Close-up of yellow flower with five petals and numerous stamens
Norman E. Rees, USDA Agricultural Research Service

Common St. Johnswort is an introduced species that can quickly crowd out other plants in disturbed areas, but does not readily colonize undisturbed areas. It is poisonous to livestock, but it provides a pollen source for wasps and bees.

St. Johnswort grows in a variety of dry, sunny habitats, particularly grasslands, rangelands, or areas disturbed by fire. Plants grow to a height of three feet with many flowers on each plant. Flowers are yellow, with five petals, and a diameter of 3/4 to 1 inch. Leaves are narrow and oblong.

Flower cluster with some flowers past bloom, petals turned dry and pink
Steve Dewey, Utah State University, Bugwood.org
Flower cluster with some flowers past bloom and turning to seed
Eric Coombs, Oregon Department of Agriculture, Bugwood.org
Growth habit with upright stems and narrow, oblong foliage all the way up to a terminal flower
William M. Ciesla, Forest Health Management Intern
Side view of flower at the end of a leafy stem. Flower's stamens stand upright, and the petals tend downwards
William M. Ciesla, Forest Health Management Intern
The flower has five widely spaced yellow petals
William M. Ciesla, Forest Health Management Intern
Scientific Name
Hypericum perforatum
Plant Type
Forb
Growing Season
Warm Season
Poisonous to most livestock
Habitat
Grasslands
Flower Color
Yellow
⚠
Toxic to livestock
✓
Pollen source for bees and wasps
For definitions, see the glossary.

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