Diplacus fremontii
One sided monkeyflower
Photo by Chez Brungraber
Family: Phrymaceae · Type: Annual · Native
Conservation status: CNPS 4.3
Diplacus fremontii (One sided monkeyflower) is a native California annual in the Phrymaceae family, recognized by one flower per node diagnostic.
One sided monkeyflower is a California native annual found in southern Coast Ranges, southwestern California, and southern Mojave Desert in sandy, shrubby, disturbed areas and streambanks at elevations below 2,100 meters. Flowering from March to June, this plant produces magenta to dark red-purple flowers with yellow throat folds, individually positioned at each node. Growing with slender stems 1 to 20 centimeters tall, the plant has a delicate, compact structure. Its leaves range from 2 to 30 millimeters long, generally narrowly elliptic or obovate, with lower leaves smooth and upper leaves slightly hairy. The calyx is distinctive, swollen with wide ribs and generally tinged red with white hairs, measuring 5 to 14 millimeters long.
Identification and appearance
Key characters: 21 sympatric species; one flower per node diagnostic
Habitat and range
Habitat: Sandy, shrubby, disturbed areas, generally on streambanks
Elevation: < 2100 m
Outside California: northern Baja California
Bloom period
Diplacus fremontii blooms Mar-Jun.
Conservation status
CNPS 4.3
How to tell it apart
vs Erythranthe: Diplacus has a corolla that withers and stays attached and typically grows in dry, rocky places; Erythranthe drops its corolla cleanly and favors wet seeps and streambanks.; vs Mimulus: Diplacus covers the shrubby and small annual western monkeyflowers with ribbed, inflating calyces; Mimulus (in the strict sense) is a fleshy-stemmed perennial with squarish 4-angled stems.; vs Mimetanthe: Diplacus is puberulent to glandular with a distinctly 2-lipped flower; Mimetanthe is densely long-soft-wavy-hairy with tiny yellow flowers and a nearly regular calyx.; vs Collinsia: Diplacus has an open funnel-throated corolla and a 5-ribbed calyx; Collinsia has a sharply 2-lipped flower with the middle lower lobe folded into a keel that hides the stamens.; vs Antirrhinum: Diplacus has an open-throated corolla and free calyx lobes; Antirrhinum (snapdragon) has a closed, pouched throat sealed by a palate and a spurless sac at the base.
Frequently asked questions
Is Diplacus fremontii native to California?
Yes. Diplacus fremontii is native to California (recorded as native).
When does Diplacus fremontii bloom?
Diplacus fremontii blooms Mar-Jun.
What plant family does Diplacus fremontii belong to?
Diplacus fremontii is in the Phrymaceae family, genus Diplacus.
Is Diplacus fremontii rare or endangered?
Diplacus fremontii carries California Rare Plant Rank 4.3, state rank S2?.
What habitat does Diplacus fremontii grow in?
Diplacus fremontii grows in Sandy, shrubby, disturbed areas, generally on streambanks.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CalPhotos
Last updated 2026-10-06
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.