Cyclospermum leptophyllum
Marsh parsley
(c) Douglas Goldman, some rights reserved (CC BY-SA), uploaded by Douglas Goldman · licence
Family: Apiaceae · Type: Herb · Not Native
Cyclospermum leptophyllum (Marsh parsley) is a non-native California herb in the Apiaceae family, recognized by Widespread weedy species, only Cyclospermum naturalized in California.
Marsh parsley is a naturalized annual found in the north coastal ranges, central California valleys, central Coast Ranges, San Francisco Bay Area, southern coastal ranges, and southern California coastal areas along roadsides at elevations below 350 meters. Flowering from April to August, this plant produces tiny white flowers in small compact clusters less than 2 centimeters wide. Growing with slender stems 20 to 60 centimeters tall, it has a delicate, spreading habit with multiple thin branches. Its finely divided leaves are 3.5 to 10 centimeters long, featuring thread-like to linear segments 3 to 15 millimeters in length that give the plant a feathery, intricate appearance. The fruit is small, elliptic to ovate, measuring 1.2 to 3 millimeters wide.
Identification and appearance
Key characters: Widespread weedy species, only Cyclospermum naturalized in California
Habitat and range
Habitat: Roadsides
Elevation: < 350 m
California counties: Los Angeles, San Diego, Alameda, Riverside, Fresno, Merced, Orange, San Mateo, Kern, Santa Barbara, Monterey, San Francisco, Sacramento, Contra Costa, Stanislaus, Santa Clara, San Luis Obispo, San Joaquin, Placer, Butte, Humboldt, Santa Cruz, San Bernardino, Ventura, Yolo
Outside California: +- worldwide, warm temperate.
Bloom period
Cyclospermum leptophyllum blooms Apr-Aug.
How to tell it apart
vs Apiastrum: Cyclospermum has alternate leaves; Apiastrum has opposite leaves in pairs.; vs Foeniculum: Cyclospermum has small white flowers and smooth fruits; Foeniculum has yellow flowers and ribbed fruits.; vs Ptilimnium: Cyclospermum lacks involucels around flower clusters; Ptilimnium has thread-like involucels.; vs Anethum: Cyclospermum has white flowers and tiny fruits; Anethum has yellow flowers and flat winged fruits.; vs Asparagus: Cyclospermum is an upright herb with umbels; Asparagus is a feathery-leaved sprawling plant.
Frequently asked questions
Is Cyclospermum leptophyllum native to California?
No. Cyclospermum leptophyllum is not native to California (recorded as not native).
When does Cyclospermum leptophyllum bloom?
Cyclospermum leptophyllum blooms Apr-Aug.
Where in California does Cyclospermum leptophyllum grow?
Cyclospermum leptophyllum occurs in Los Angeles, San Diego, Alameda, Riverside, Fresno, Merced, Orange, San Mateo and other counties, at elevations of < 350 m.
What plant family does Cyclospermum leptophyllum belong to?
Cyclospermum leptophyllum is in the Apiaceae family, genus Cyclospermum.
What habitat does Cyclospermum leptophyllum grow in?
Cyclospermum leptophyllum grows in Roadsides.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · 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.