Taxon Report

Lyonothamnus floribundus Gray ssp. aspleniifolius (Greene) Raven

Santa Cruz Island ironwood

Print Report

Taxon Summary

Lyonothamnus floribundus ssp. aspleniifolius, commonly known as Santa Cruz Island ironwood, is a perennial evergreen tree in the Rosaceae that is found only in California. It occurs within Broadleafed upland forest, Chaparral, and Cismontane woodland, growing at elevations from 20 to 580 meters. Lyonothamnus floribundus ssp. aspleniifolius is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

Classification


Scientific Name:	Lyonothamnus floribundus Gray ssp. aspleniifolius (Greene) Raven
Common Name:	Santa Cruz Island ironwood
Family:	Rosaceae
Element Code:	PDROS12011
USDA Plants Symbol:	LYFLA
Synonyms/Other Names:

Ecology and Life History


Lifeform:	perennial evergreen tree
Blooming Period: May-Jul	May-Jul
Elevation:	20-580 (65-1905)
General Habitats:	Broadleafed upland forest, Chaparral, Cismontane woodland
Microhabitat:
Microhabitat Details:

Conservation Status


CA Rare Plant Rank:	1B.2
Global Rank:	G3T3
State Rank:	S3
State List:	None
Fed List:	None
Other Status:	IUCN_VU; SB_CalBG/RSABG
CRPR Changes:

Occurrence Data from the CNDDB


Total Occurrences:	78
Element Occurrence Ranks:
Excellent (A)	0
Good (B)	2
Fair (C)	0
Poor (D)	0
None (X)	0
Unknown (U)	76

Location


California Endemic: True
California Counties and Islands: Name (Code)
Los Angeles (LAX), Santa Barbara (SBA)
Quads: Name (Quad Code)
San Clemente Island Central (3211874), San Clemente Island South (3211873), Santa Cruz Island A (3311987), Santa Cruz Island B (3311986), Santa Cruz Island C (3311985), Santa Cruz Island D (3311984), Santa Rosa Island East (3311988), Santa Rosa Island North (3312081), Santa Rosa Island South (3312071)

Threat List Data from the CNDDB


Threat List Total:	0
EOs with Threat Listed:	Total EOs	% of EOs
	0	%

Notes



Can bloom intermittently through much of year. Threatened by grazing on SCZ and SRO islands. Feral herbivores removed from SCM Isl.; stump-sprouting noted.
Threats:

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 4 November 2025].