Magnoliopsida (Flowering Plants): Malvaceae

Hall’s Bush-mallow (Malacothamnus hallii)

Potential Occurrence:Not Expected to Occur

Status:

Federal:None

State:None

CNPS:1B.2

Other: None

Species Description: Hall’s Bush-mallow grows to 3 m with spreading stout branches and sessile, white, dense, shaggy hairs (Rosattii 2008). The leaves are wider than long, cordate and shallowly 3 to 7 lobed (Rosattii 2008).The inflorescence is a panicle like with 3 to 7 flowers per node and leaf like bracts (Rosattii 2008).The flower buds area rounded with calyx lobes awl shaped to lanceolate and petals pale pink to purplish white.The fruit segments are 3 to 5 mm, shallowly notched and brown (Rosattii 2008).

Nomenclature: Malacothamnus hallii (Eastw.) Kearney Malvaceae (Regents of the University of California 2010)

Synonyms:Malacothamnus fasciculatus (Torrey & A. Gray) E. Greene, Malvastrum halliiEastw. (Regents of the University of California 2010)

Distribution:This species occurs throughout California in the North Coast Ranges, the Sierra Nevada Foothills, the central High Sierra Nevada, the San Joaquin Valley and the San Francisco Bay Area (Rosattii 2010). CNPS (2010) finds Mendocino County occurrence needs verification.

Life History & Threats:Hall’s Bush-mallow is an evergreen shrub blooming from May to October and is threatened by development and non-native plants (CNPS 2010).

Habitat & Habitat Associations:

Vegetation Types:Habitat for this species is chaparral dominated by mostly evergreen shrubs with thick, leathery leaves and stiff branches (CNPS 2010).

Topography and Microclimates:open chaparral (Rosattii 2008)

Elevation: 10 to 760 m (CNPS 2010) (The Study Area ranges from 230 to 710 m)

Conceptual Basis for GIS Model Development:Potential habitat in the Study Area was mapped as chaparral (i.e. Northern Mixed chaparral or scrub oak).

Potential Occurrence in the Galbreath Wildlands Preserve:

Habitat: Habitat preferred by the Hall’s Bush-mallow is limited to chaparral dominated by evergreen shrubs. Although scattered chaparral species (i.e., chamise) have been found in isolated locations on south-facing slopes in the Preserve, the GIS map generally provides an accurate description of chaparral distributionas not occurring within the Galbreath Wildlands Preserve.

Nearest Occurrence:

Documented Occurrences in the Galbreath Wildlands Preserve: A previous site visit of the Galbreath Wildlands Preserve did not find this species (SSU Field Station and Nature Preserves 2010)

Nearest Occurrence to the Galbreath Wildlands Preserve: North of the Bay Area, Hall’s Bush Mallow is known only from Mendocino County (4 occurrences) north of the Preserve and to the east in Lake County (1 occurrence). (Calflora 2010).The nearest occurrence to the Preserve is approximately 13 miles northeast of the Preserve in the Navarro River watershed (Calflora 2010).

Summary:We anticipate that this species is “Not Expected to Occur” in the Galbreath Wildlands Preserve due to the lack of potential habitat (chaparral).

References

Calflora. 2010. Information on California plants for education, research and conservation.< 2010 Jul 2.

California Native Plant Society (CNPS). 2010. Inventory of Rare and Endangered Plants. Online edition, v7-10b. < Accessed 2010 Jul 2.

Rosatti T. 2008. DRAFT Second Edition of the Jepson Manual: Vascular plants of California.< Accessed 2010 Jul 2.

SSU Field Stations and Nature Preserves. 2010. Galbreath Wildlands Preserve Vascular Plant List. Compiled by CNPS Milo Baker Chapter, Linden Schneider, and others. < Accessed 2010 Jun.

Regents of the University of California. 2010. The Jepson Online Interchange California Floristics. < Accessed 2010 Jul 19.

Species Account Description:Linden Schneider & Emily Harvey