Malta starthistle
Centaurea melitensis L.


Centaurea melitensis is a winter annual with a yellow-flowered, spiny head that can reach a height of 3.3 ft. (1 m). tall.
Leaves are alternate, linear or narrowly oblong with smooth, toothed margins. Leaf bases are decurrent and give the stems a winged appearance.
Flowers are yellow, 0.5 in. (1.3 cm) across, and surrounded by sharp, tan, 0.5 in. (1.3 cm) long, spiny cobwebbed bracts. Blooming occurs from April to September.
The fruit are 0.08-0.12 in. (2-3 mm) in length, grayish to tan in color with deeply notched bases and tan bristles that are 0.04-0.12 in. (1-3 mm) long.
Ecological Threat
Centaurea melitensis prefers disturbed areas such as grasslands, open woodlands, roadsides, fields, and pastures. It is native to Europe and North America.


Selected Images


EDDMapS Distribution

EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit

State Regulated List

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Subclass: Asteridae
Order: Asterales
Family: Asteraceae
Genus: Centaurea
Subject: Centaurea melitensis L.

Synonyms and Other Names

Other Common Names:
Maltese star-thistle, Malta starthistle, Maltese star thistle, Napa thistle, spotted knapweed, tocalote


Plants - Forbs/Herbs