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Taxon  Report  
Centaurea melitensis  L.
Maltese star thistle,   Napa star thistle,   Tocalote
Centaurea melitensis is an annual herb that is not native to California.
Cal-IPC rating: moderate
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Observation Search
(9883 records)
redone or more occurrences
within a 7.5-minute quadrangle

Bloom Period
Genus: Centaurea
Family: Asteraceae  
Category: angiosperm  
PLANTS group:Dicot
Jepson eFlora section: eudicot

Habitat: disturbed

Communities: weed, characteristic of disturbed places, agricultural weed

Name Status:
Accepted by JEF + PLANTS

Information about  Centaurea melitensis from other sources

[Cal-IPC] Invasive: Centaurea melitensis (Malta starthistle, tocalote) is a bushy annual (family Asteraceae) found throughout most of California and in many other western states. Malta starthistle prefers disturbed and open areas, including grasslands, open woodlands, agricultural fields and roadsides. It is most invasive in California?s central western and southwestern regions. While Malta starthistle is less invasive than yellow starthistle (Centaurea solstitialis), it still spreads quickly by producing great quantities of seed if given the proper conditions. Insects such as the false peacock fly (Chaetorellia succinea) and hairy weevil (Eustenopus villosus) have been used as biological controls with some success. Cal-IPC Rating: Moderate (contributed by Mary Ann Machi)

[Wikipedia] Europe & Africa native: Centaurea melitensis (called Maltese star-thistle[1][2] in Europe, tocalote or tocolote in western North America) is an annual plant in the family Asteraceae, 1 to 11 decimetres (4 to 43 in) high, with resin-dotted leaves and spine-tipped phyllaries. This plant is native to the Mediterranean region of Europe and Africa. It was introduced to North America in the 18th century; the first documented occurrence in California is in the adobe of a building constructed in San Fernando in 1797. It is also naturalized on a number of Pacific islands. (contributed by Mary Ann Machi)

Suggested Citation
Calflora: Information on California plants for education, research and conservation, with data contributed by public and private institutions and individuals. [web application]. 2023. Berkeley, California: The Calflora Database [a non-profit organization]. Available: https://www.calflora.org/   (Accessed: 12/03/2023).