Synonym(s): Phelipanche ramosa
Family: Orobanchaceae (Broom-Rape Family)
Duration and Habit: Annual Herb
Plant annual, biennial, or perennial, depending mainly on host; stems 10-40 cm tall, swollen at base, attached to host roots, simple or branched, glandular puberulent; leaves reduced to scales, 3-10 mm, ovate to ovate-lanceolate, acute; inflorescence 2-25 cm, lax to moderately dense, glandular pubescent; bracts 6-10 mm, ovate-lanceolate; bracteoles linear-lanceolate, about equalling calyx; pedicels 0-8 mm; entire plant lacking chlorophyll, yellow or yellowish violet; calyx 6-8 mm; corolla 10-22 mm; glandular-pubescent, suberect and inflated at base, white or yellow to violet or bluish, usually pale; filaments inserted 3-6 mm above base of corolla; stigma white, cream or pale blue; capsule 6-10 mm containing numerous dust-like seeds. Plants highly variable where native; less so in introduced populations.
Native Lookalikes: Currently no information available here yet, or there are no native Texas species that could be confused with Hemp broomrape.
Ecological Threat: Hemp broomrape is a worldwide noxious parasite of many crops and associated weeds. Heavy infestations can severely damage crops.
Biology & Spread: Reproduces by seed. Seed disperses with human activities, farm machinery, water, and wind.
History: Orobanche ramosa is native to the Mediterranean area of southern Europe but has been spread to a number of other parts of the world.
U.S. Habitat: Ornamental and vegetable crop fields, especially tomato fields.
U.S. Nativity: Introduced to U.S.
Native Origin: Introduced from Europe
U.S. Present: CA, IL, KY, NC, NJ, TX
Distribution in Texas: Present distribution includes southern Europe (occasionally introduced farther north) to Russia and Siberia. It is also present in northern and southern Africa and the Middle East. In the Americas, O. ramosa has been introduced and is established in the U. S., Mexico, and Cuba. It was reported at one time infesting hemp and tobacco in Kentucky.
List All Observations of Orobanche ramosa reported by Citizen Scientists
There are several native broomrapes in California, a few of which are uncommon to rare, but only Cooper's broomrape occurs in the Mojave and Sonoran deserts (excluding desert mountains) and is a weed of vegetable crops. Unlike branched broomrape, native broomrapes have 5-lobed calyces.
Hand pulling plants, plowing under trap crops before seed production, or burying seed with one deep inversion plowing can help control infestations.USE PESTICIDES WISELY: ALWAYS READ THE ENTIRE PESTICIDE LABEL CAREFULLY, FOLLOW ALL MIXING AND APPLICATION INSTRUCTIONS AND WEAR ALL RECOMMENDED PERSONAL PROTECTIVE GEAR AND CLOTHING. CONTACT YOUR STATE DEPARTMENT OF AGRICULTURE FOR ANY ADDITIONAL PESTICIDE USE REQUIREMENTS, RESTRICTIONS OR RECOMMENDATIONS. MENTION OF PESTICIDE PRODUCTS ON THIS WEB SITE DOES NOT CONSTITUTE ENDORSEMENT OF ANY MATERIAL.
Dhanapal, G. N., P. C. Struik, M. Udayakumar, and J. M. Timmermans. 1996. Management of Broomrape (Orobanche spp.) - A review. Journal of Agronomy and Crop Science 175:335-359.
Foy, C. L., R. Jain, and R. Jacobsohn. 1989. Recent approaches for chemical control of broomrape (Orobanche spp.). Reviews in Weed Science 4:123-152.
Holm, L., J. Doll, E. Holm, J. Pancho, and J. Herberger. 1997. Obligate parasitic weeds: Orobanche ramosa L., and Orobanche minor Sm. In 'World Weeds: Natural Histories and Distribution' pp. 511-530 (John Wiley & Sons Inc: New York).
Mitich, L. W. 1993. Orobanche-The Broomrapes. Weed Technology 7:532-535.
Musselman, L. J. 1980. The biology of Striga, Orobanche, and other root-parasitic weeds. Annual Reviews of Phytopathology 18:463-489.
Stout, G. L. 1938. A recurrence of broomrape (Orobanche ramosa L.) on tomato plants in California. California Department of Agriculture Bulletin 27(2):166-171.
Encycloweedia, California Department of Food and Agriculture
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