Taxon Report

Arctostaphylos myrtifolia Parry

Ione manzanita

Print Report


© 2006 Steve Matson

Species Description:
Arctostaphylos myrtifolia, commonly known as Ione manzanita, is a perennial evergreen shrub in the Ericaceae that is found only in California. It occurs within Chaparral, and Cismontane woodland, growing at elevations from 60 to 580 meters. Arctostaphylos myrtifolia is ranked 1B.2, Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California.

  Classification

Scientific Name:
Arctostaphylos myrtifolia Parry
Common Name:
Ione manzanita
Family: Ericaceae
Element Code: PDERI04240
USDA Plants Symbol: ARMY
Synonyms/Other Names:

Ecology and Life History

Lifeform: perennial evergreen shrub
Blooming Period: Nov-Mar Nov-Mar
Elevation: 60-580 (195-1905)
General Habitats: Chaparral, Cismontane woodland
Microhabitat: Acidic, Clay (sometimes), Sandy (sometimes)
Microhabitat Details: Ione soil

Occurrence Data from the CNDDB

Total Occurrences: 11
Element Occurrence Ranks:
   Excellent (A) 1
   Good (B) 5
   Fair (C) 0
   Poor (D) 0
   None (X) 0
   Unknown (U) 5
California Endemic:  True
California Counties and Islands: Name (Code)
Amador (AMA), Calaveras (CAL)
Quads: Name (Quad Code)
Carbondale (3812141), Ione (3812038), Irish Hill (3812048), Mokelumne Hill (3812036), San Andreas (3812026), Valley Springs (3812027), Wallace (3812028)

Threat List Data from the CNDDB

Threat List Total: 8
EOs with Threat Listed: Total EOs % of EOs
7 64 %
Mining 6 54%
Development 4 36%
Road/trail construction/maint. 4 36%
Disease 3 27%
ORV activity 3 27%
Grazing 1 9%
Vandalism/dumping/litter 1 9%
Agriculture 1 9%

Notes

Protected in part at Ione Manzanita ACEC (BLM) and Apricum Hill ER (CDFW), both in AMA Co. 
Threats:

Threatened by erosion, mining, development, and fungal infection. 

Taxonomy:

See Pittonia 1:34 (1887) for original description, Ecology 45(4):792-808 (1964) for ecological discussion, and Changing Seasons 1(4):4-19 (1982) for species account.

Citation California Native Plant Society, Rare Plant Program. 2025. Rare Plant Inventory (online edition, v9.5.1). Website https://www.rareplants.cnps.org [accessed 24 January 2025].