Volutaria muricata
Morocco knapweed
(c) Jacek Pietruszewski, some rights reserved (CC BY) · licence
Family: Asteraceae · Type: Herb · Not Native
Volutaria muricata (Morocco knapweed) is a non-native California herb in the Asteraceae family.
Morocco knapweed is a naturalized annual found in southern California coastal areas in disturbed sites at elevations below 100 meters. Flowering from March to May, this plant produces pale flowers in solitary heads approximately 15 to 18 millimeters wide with dark-margined phyllaries. Growing with stems up to 50 centimeters tall covered in soft, jointed hairs, it has a distinctive branching habit. Its lower leaves are oblanceolate and deeply lobed, while upper leaves become progressively smaller and more linear, with soft hairy surfaces dotted with minute glands. The flower heads feature involucre phyllaries with spine tips up to 5 millimeters long, creating an intricate architectural structure.
Identification and appearance
Key characters: 0 sympatric species - geographically isolated in South Coast region
Habitat and range
Habitat: Disturbed sites
Elevation: < 100 m
Outside California: southwestern Europe, northwestern Africa
Bloom period
Volutaria muricata blooms Mar-May.
How to tell it apart
vs Centaurea: Volutaria bract margins smooth/minutely toothed; Centaurea bract tips fringed with multiple spines or teeth; vs Lessingia: Lessingia has bristly pappus and annual taproot; Volutaria has scaly pappus and smooth-spined bracts; vs Tanacetum: Tanacetum has fern-like leaves and buttonlike flowers; Volutaria simple leaves and spiny-bracted heads; vs Arctium: Arctium bracts hooked at tips; Volutaria bracts with straight flattened spines; vs Saussurea: Saussurea bracts not spine-tipped; Volutaria bracts taper to distinct flattened spines
Frequently asked questions
Is Volutaria muricata native to California?
No. Volutaria muricata is not native to California (recorded as not native).
When does Volutaria muricata bloom?
Volutaria muricata blooms Mar-May.
What plant family does Volutaria muricata belong to?
Volutaria muricata is in the Asteraceae family, genus Volutaria.
What habitat does Volutaria muricata grow in?
Volutaria muricata grows in Disturbed sites.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.