Magnoliopsida (Flowering Plants): Convolvulaceae
Three Fingered Morning Glory (Calystegia collina ssp. tridactylosa)
Potential Occurrence: Unlikely to Occur
Status:
Federal: none
State: none
CNPS: 1B.2
Other: none
Photos: BLM, Arcata Field
Office
Species Description: The Three Fingered Morning Glory is densely tomentose and decumbent
with long brownish hairs that is not or weakly climbing (Hickman 1996). The leaf is generally 3
cm at mid rib with 2 distinct basal lobes and a barley wavy margin (Hickman 1996). The
inflorescence is solitary with linear elliptic to lanceolate bracts not fully enclosing the calyx
(Hickman 1996). The flower is showy with tomentose sepals and a glabrous white corolla
(Hickman 1996). The fruit is a spheric capsule with about 4 seeds (Hickman 1996).
Nomenclature: Calystegia collina (Greene) Brummitt ssp. tridactylosa (Eastw.) Brummitt
Convolvulaceae (USDA 2010)
Synonyms: C. tridactylosa, (Hickman 1996)
Distribution: This species occurs in the North Coast Range particularly in Mendocino and Lake
counties (Hickman 1996).
Life History & Threats: The Three Fingered Morning Glory is a rhizomatous perennial herb
(CNPS 2010; Hickman 1996). It is a broad serpentine endemic with 85 to 94% of occurrences
being on ultramafics (Calflora 2010). It is potentially threatened by geothermal energy
development (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, cismontane woodland dominated by trees that are
deciduous, evergreen or both with open canopies, and oak-pine woodlands (CNPS 2010;
Hickman 1996).
Topography and Microclimates: Open grassy or rocky areas (CNPS 2010; Hickman 1996)
Elevation: 0 to 600 m (CNPS 2010) (The Study Area ranges from 200 to 740 m).
Geology and Soils: Rocky, gravelly, or serpentinite (CNPS 2010; Hickman 1996). Heavy clay
soil (Janeway 2002).
Species Associations: Found with Kellogg’s yampah (Perideria kelloggii), hayfield tarweed
(Hemizonia congesta), and aster species (Lessingia sp.) (Janeway 2002).
Conceptual Basis for GIS Model Development: Potential habitat in the Study Area was
mapped as areas:

below 630 m (includes a 30 m buffer on known elevational occurrences of this species

chaparral (including scrub oak) or woodlands (i.e. mixed or single dominant hardwoods
with a canopy cover < 40%)
Best potential habitat was mapped as areas in the above vegetation types with:

rocky (i.e., gravelly (gravelly loam, very gravelly loam, cobbly loam, very cobbly loam, or
alluvium) or clay (i.e., clay loam) soils
Potential Occurrence in the Galbreath Wildlands Preserve:
Habitat: Best potential habitat in the Preserve for Three Fingered Morning Glory is woodlands
with rocky or clay soils. This habitat type is present in the center and eastern portion of the
Preserve.
Habitat quality is poor. While rocky and clay soils are abundant in woodland areas of the
Preserve, this habitat type is not a common type for this species. Three Fingered Morning Glory
occurrence is highly correlated with ultramafic soils, such as serpentine. To verify the lack of
serpentine soils reported in the Preserve in GIS information, we identified all areas (11 sites) of
exposed rocky soils from high-resolution satellite imagery. During site visits to these areas, the
only serpentine found were rocks exposed by road maintenance activity at a waterbar. In
addition, chaparral, a common habitat type for this species, also does not occur in the 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: All reported occurrences for
this species are to the east of the Preserve in Mendocino, Lake and Colusa counties
(Calflora 2010). In Mendocino County, the species is known from 10 occurrences in four
adjacent USGS quads in the northcentral region of the County. The nearest occurrence
to the Preserve is 50 miles to the northeast in the Upper Eel River watershed (Calflora
2010).
Summary: Three Fingered Morning Glory is “Unlikely to Occur” in the Preserve because habitat
quality is poor, occurrence at the Preserve would constitute a western range extension for the
species, and the species has not been documented to occur nearby (relative to distances
observed among other documented occurrences).
References
Bureau of Land Management, Arcata Field Office (BLM). 2003. Calystegia collina ssp.
tridactylosa; Coast Range False Bindweed.
<http://calphotos.berkeley.edu/cgi/img_query?enlarge=0000+0000+1203+0598>. Accessed
2010 Oct 25.
Calflora. 2010. Information on California plants for education, research and
conservation.<http://www.calflora.org/>. Accessed 2010 Jun 29.
California Native Plant Society (CNPS). 2010. Inventory of Rare and Endangered Plants. Online
edition, v7-10b. <http://www.cnps.org/inventory>. Accessed 2010 Jun 29.
Hickman JC editor. 1996. The Jepson Manual Higher Plants of California. 3rded.. London:
University of California Press, Ltd. 518 p.
Janeway LP. 2002. Consortium of California Herbaria. <http://ucjeps.berkeley.edu/cgibin/new_detail.pl?CHSC83430>. Accessed 2010 Jun 29.
SSU Field Stations and Nature Preserves. 2010. Galbreath Wildlands Preserve Vascular Plant
List. <http://www.sonoma.edu/preserves/docs/galbreath_vascular_plants.pdf>. Accessed 2010
Jun.
United States Department of Agriculture (USDA). 2010. PLANTS Profile.
<http://plants.usda.gov/java/nameSearch?mode=symbol&keywordquery=CACOT>. Accessed
2010 Oct 25.
Species Account Description: Linden Schneider