Appearance

Orobanche minor is a fleshy, herbaceous, annual, parasitic plant that grows up to 22 in. (55.9 cm) tall. It attaches to the roots of broadleaf hosts (especially Trifolium spp.). The fleshy stem is yellow to straw colored and sticky.

Foliage

Leaves are greatly reduced (vestigial), alternate and triangular shaped.

Flowers

Flowers, borne on terminal clusters, are snapdragon-like, with 0.5 in. (1.3 cm) long, purple-tinged petals. Flowering occurs in the winter and spring.

Fruit

This plant is highly prolific. Seeds are very small (dust-size) and remain viable for 10 or more years.

Ecological Threat

Orobanche minor is a Federal Noxious Weed and concern exists that it may spread to infest crops such as legume forages and leafy green vegetables. Heavy infestations can cause crop failure. It is native to the Middle East and was probably introduced into North America with contaminated seed.

Resources

• Fact Sheet - Georgia Cooperative Agricultural Pest Survey
• Federal Noxious Weed Disseminules of the U.S. - USDA-APHIS
• Weed of the Week - USDA Forest Service

Selected Images

Maps

Invasive Listing Sources

• Georgia Exotic Pest Plant Council - Category 4
• Invasive Species of Concern in Georgia
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• Oregon Noxious Weeds
• Pacific Northwest Exotic Pest Plant Council, 1998
• Virginia Invasive Species Management Plan 2012
• WeedUS - Database of Plants Invading Natural Areas in the United States

References