Taxon Report

Cercocarpus traskiae Eastw.

Catalina Island mountain-mahogany

Print Report

Taxon Summary

Cercocarpus traskiae, commonly known as Catalina Island mountain-mahogany, is a perennial evergreen shrub in the Rosaceae that is found only in California. It occurs within Chaparral, and Coastal scrub, growing at elevations from 100 to 250 meters. Cercocarpus traskiae is ranked 1B.1, Plants Rare, Threatened or Endangered in California and Elsewhere; Seriously threatened in California.

Classification


Scientific Name:	Cercocarpus traskiae Eastw.
Common Name:	Catalina Island mountain-mahogany
Family:	Rosaceae
Element Code:	PDROS08030
USDA Plants Symbol:	CETR4
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial evergreen shrub
Blooming Period: Mar-May	Mar-May
Elevation:	100-250 (330-820)
General Habitats:	Chaparral, Coastal scrub
Microhabitat:	Gabbroic, Rocky
Microhabitat Details:	sausserite gabbro

Conservation Status


CA Rare Plant Rank:	1B.1
Global Rank:	G1
State Rank:	S1
State List:	CE
Fed List:	FE
Other Status:	IUCN_CR; SB_CalBG/RSABG; SB_CRES
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	1
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	1
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	0

Location


California Endemic: True
California Counties and Islands: Name (Code)
Los Angeles (LAX)
Quads: Name (Quad Code)
Santa Catalina South (3311834)

Threat List Data from the CNDDB


Threat List Total:	5
EOs with Threat Listed:	Total EOs	% of EOs
	1	100 %
Erosion/runoff	1	100%
Grazing	1	100%
Hybridization	1	100%
Insufficient population/stand size	1	100%
Other	1	100%

Notes



Known from only one occurrence with fewer than 15 trees in Wild Boar Gully; one of the rarest trees in CA. Mainland occurrence of one plant from LAX Co. (113C) needs confirmation; possibly introduced or hybrid with C. betuloides var. betuloides. Recovery work in progress. See Proceedings of the California Academy of Sciences III 1:136 (1898) for original description, and Conservation Biology 3(1):52-58 (1989) for discussion of hybridization.
Threats:
Threatened by feral herbivores and hybridization.
Taxonomy:

Selected References

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 3 November 2025].