(2007)  
 
Rosa spithamea S.Watson
Possible Synonyms (working list):
R. adenocarpa Greene Leafl. Bot. Observ. Crit. 2: 261. 1912:... [hips of spithamea, but prickles and leaflet shape of bridgesii]

(2007)  
 
Subgenus Rosa, Section Gymnocarpae
Rosa bridgesii Crépin ex Rydberg
Flowers commonly solitary; terminal leaflet very blunt and flat; leaf margins widely serrated; leaves finely hairy; prickles paired at nodes; open forest floors at elevations of 3000 to 6500 feet of the central and southern Sierra Nevada and southern Cascades.
Rosa bridgesii described here replaces the inland Rosa pinetorum described by Munz in A Flora of California (1959) and R. spithamea and R. gymnocarpa var. pubescens in the Sierra Nevada.
Gives detailed explanation of status of nomenclature and possible synonyms:
R. calvaria Greene; R. crenulata Greene; R. dudleyi Rydb.; R. gymnocarpa var. pubescens S. Watson; R. lesterae Eastwood; R. spithamea var. subinermis Engelm.; and R. yainacensis Greene.

(2001)  Includes photo(s).
 
Note: This website by Dr. Ertter differentiates California's native roses with comparative tables as well as descriptions and pictures.
Subgenus Rosa, Section Cinnamomeae. hexaploid (n=21) Thicket-Forming Roses
Rosa nutkana var. nutkana
"California is the southern end of the range....Although reported in The Jepson Manual as occurring only as far south as Mendocino County..., the Nootka rose has now been verified in coastal marshes of Marin and San Luis Obispo counties as well, perhaps intergrading with R. californica.
"Flowers and hips relatively large, often solitary... [T]hick-based paired prickles in upper part of plant. Prickles often dense. Edge of coastal marshes and inland clearings, below 700 meter elevation."

(2001)  
 
Barbara Ertter's Native California Roses notes that Rosa pinetorum is differentiated from Rosa bridgesii, a similar species now thought to be restricted to the Sierra Nevada. Pinetorum is not thicket-forming, usually appearing as solitary canes in the understory. Blooms in clusters of 2 to 5. Hips round.

(2007)  Includes photo(s).
 
Rosa pisocarpa A. Gray Cluster Rose
Subgenus Rosa, Section Cinnamomeae: A Thicket-Forming Rose
Lank shrub to thicket, 5-25 dm tall [20 inches to 8 feet]. Stem generally black; prickles few, generally paired at nodes, sometimes nearly lacking...; leaflets 2 - 3 per side, sparsely hairy to glabrous, leaf margins single toothed, generally glandless; inflorescence 2 - 10; blooming June to August. Generally moist or shady areas at forest edge; 30 - 2100 meter elevation.
North Coast Range and Klamath/Siskiyou Ranges of Northern California north on the west side of the Cascades to British Columbia.
Diploid.

(2007)  
 
Subgenus Rosa, Section Gymnocarpae: Wood and Ground Roses

Rosa spithamea S. Watson
Low growing, most likely to flower after fires; blooms several to a cluster; many stalked glands on the receptacle and sepals; many straight prickles; 6 to 24 inches tall; round hips with persistent sepals; native to north and central coast ranges from Monterey north, Siskiyou Mountains. Blooms April to August especially where recently burned.

(2007)  
 
R. yainacensis may or may not represent the same species as Rosa bridgesii. Recent field work in the presumed locality of R. yainacensis, Yainax Ridge in Klamath County, Oregon, has not produced specimens of R. yainacensis for study.