Walter Hodge, USF Herbarium Slide Collection

Family: Asteraceae

Synonym(s): Conyza cinerea L., Senecioides cinerea (L.)
Vernonia cinerea (L.) Less., Vernonia cinerea (L.)
Less. var. parviflora (Reinw.)

Duration: Annual

Habit: Herb

Listed by:
Invasive Plant Atlas of the US: 0
Federal Noxious Weed: 0
TDA Noxious Weed: 0
TPWD Prohibited Exotic Species: 0

Description: Cyanthillium cinereum or Little Ironweed usually flowers and fruits as an herb, but can grow to be about 1 m tall and resemble a shrub. Leaves, stems, and petioles are covered with wooly hairs. Leaves are alternate, between 3-4 cm long and 1.5 - 3 cm wide. Leaves taper gradually into the petiole, which is short. The flower heads have purple to pink inflorescence; with each head containing 20-30 flowers that are approximately 5mm long.

History: Studies show this species may have some medicinal uses. It could be what led to its spread outside of its native range.

Biology & Spread: Flowers in little ironweed are pollinated by wind. Under favorable environmental conditions it produces flowers and seeds for many months. It usually grows as a weed, thus it needs full sunlight and moderate water availability to grow. It prefers sandy-loam soils but can be found growing on a range of soils with pH ranging from 4 to 6. It can tolerate semiarid conditions and partially saline conditions

Ecological Threat: It is a fast-growing, annual herb with the capacity to form dense patches in gardens, roadsides, waste grounds and pasture. It also serves as a host plant for the Cuban slug which can be invasive outside of its native range and spread namtodes such as Angiostrongylus to mammals and humans.
C. cinereum is listed as a weed in about 27 different crops in 47 countries in Asia, Australia, Africa and America. It has the potential to negatively impact natural and seminatural habitats in coastal areas, forest edges, secondary forests, upland forests, and grasslands
Additionally, it can host the tobacco leaf curl virus and the root-knot nematode.

US Habitat: Usually found in wetlands, but occasionally found in non-wetlands. Usually found in disturbed soil. Elevation range of 100 - 2300 m.

Distribution

US Nativity: Introduced to U.S

Native Origin: Africa, Asia, Australia

US States: FL, HI, USA + (PR, VI)

Resembles/Alternatives:

Management:

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.

Listing Source

Texas Department ofAgriculture Noxious Plant List
Texas Parks and Wildlife Department Prohibited Exotic Species
Invaders Program
Federal Noxious Weed
Union of Concerned Scientists
United States Forest Service Southern Research Station

Text References

Holm L, Doll J, Holm E, Pancho J, Herberger J, 1997. World Weeds. Natural Histories and Distribution. New York, USA: John Wiley and Sons, Inc.

Pruski JF, 2013. Asteraceae. In: Flora Mesoamericana, Volume 5 (2) [ed. by Davidse, G. \Sousa Sanchez, M. \Knapp, S. \Chiang Cabrera, F.]., Mexico: Universidad Nacional Autonoma de Mexico. http://www.tropicos.org/docs/meso/asteraceae.pdf

Data Source

USDA-NRCS (2013). Plants Database: Cyanthillium cinereum. http://plants.usda.gov/java/profile?symbol=CYCI4

USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. (May 2013). http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?406954

https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.113702

Australian Tropical Rainforest Plants: Factsheet. http://keys.trin.org.au/key-server/data/0e0f0504-0103-430d-8004-060d07080d04/media/Html/taxon/Cyanthillium_cinereum.htm

Encyclopedia of Life. http://eol.org/pages/595253/overview

Last Updated: 2024-02-05 by Ashley Morgan-Olvera, TISI