Frangula betulifolia

Southwestern Colorado, near Cortez, 21 July 2008

Frangula  californica ssp. cuspidata

California. Kern Co., Erskine Creek, 08 May  2012

Frangula  californica ssp. occidentalis

California. Del Norte Co., near Gasquet, 05 Aug  2011

Frangula californica ssp. tomentella

California. Kern Co., Tehachapi Mts.south of Bear Springs Valley on old road to the Great Valley (Bakersfield)  June 2012

Frangula  purshiana ssp. purshiana

Idaho. St Joe NF: Giant White Pine along Hwy 6 and Mannering Creek, 1/4 mi S of campground, near private land; 47º00.368, 116º40.612, 2771 ft.  Wet fern-sedge meadow with high density of Veratrum californicum var. caudatum, surrounded by forest of western  red cedar, grand fir and western white pine, with understory shrubs of Alnus, Viburnum as well as Frangula purshiana.  6 Aug 2009.

Frangula  purshiana ssp. purshiana

California. Humboldt Co., Big Lagoon, July  2010

Frangula rubra ssp. obtusissima

California. Shasta Co., Salt Creek,
June 2008

Trees and Shrubs of Kern County (Jan 2013)

Key to Frangula

Twigs usually cherry red; leaves bald, wedge-shaped in
lower fourth of the blade—tapering at 45–60 degrees, more
abruptly rounded to a pointed (acute) apex.......... ............................ Frangula rubra

Twigs yellowish to greenish red or gray; leaves hairy, gradually tapered
and rounded to petiole in lower fourth of the blade, not at an abrupt 
angle, gradually rounded or angled to apex............................... Frangula californica

...... Twigs gray; hairs on lower surface of leaves all short, velvet white or
     silvery........................................................................................... ssp. tomentella

...... Twigs red; hairs leaf undersurface white, mixed long and short............... ssp. cuspidata

Frangula californica (Rhamnus californica Eschscholtz 1823) A. Gray  1849 ssp. californica.  California coffee berry. A Coast Range subspecies reported from Fulton Ranger Station, Glenville (CCH). Type from San Francisco, CA.

Frangula californica ssp. cuspidata (Rhamnus cuspidata Greene 1904) Kartesz & Gandhi 1994 [Rhamnus californica Eschscholtz ssp. cuspidata (Greene) C. B. Wolf 1938]. Coffee Berry. Erect sparingly shrub to 2 m, leafy mostly near the upper part of plant, twigs reddish with a whitish bloom, appearing somewhat deciduous, green above and paler yellowish green below, partly due to being covered by various hairs, some of which might be viewed as 'wild hairs' among the normal hairy growth, broad elliptical to slightly wider above the mid region, 2–2.5× longer that wide, 2–8 cm long, pinnately veined, with 10 or  pairs of closely parallel lateral veins, more prominent on lower surface; flowering Apr–Jul; flowers with 5 small white petals (presence of petals separates this from the genus Rhamnus, which lacks petals); fruit berry-like pyrenarium, yellow, red to black, the ovary becoming fleshy and differentiated into a hard inner layer, breaking apart at maturity into 3 separate shell-like coverings (pyrenes), each pyrene containing  1 or 2 seeds.  Chaparral, woodlands, and conifer forests, 1,500–7,500 ft, in mountains surrounding Owens Valley, disjunct to Transverse  Ranges, San Jacinto Mts., Peninsular Ranges. Type from Tehachapi, Kern Co., CA. Kern Co.: “Occasional from the Kern Plateau through the arid slopes of the mountains southwest to the Tehachapi Mountains”, pinyon juniper woodland to the Jeffrey pine forests, up to 7,500 ft” (Twisselmann), 761–2,285 m (CCH). Juniperus californica/Rhamnus tomentella ssp. cuspidata Woodland Alliance, proposed in Magney (2010) in nearby Los Angeles County, Michner Section of the Tejon Ranch Conservancy.

Frangula californica ssp. tomentella (Bentham 1848) Kartesz & Gandhi 1994 [Rhamnus californica ssp. tomentella (Bentham) C. B.  Wolf 1938]. Shrub with a tree-like habit, differing from the preceding in hairy undersurface aging more silvery but lacking the 'wild hairs', and by flowering earlier, Jan–Apr.  Also, geographically similar to the preceding.  Type from “Montibus, Sacramento,” CA. Kern Co.:  “Occasional in the chaparral in the mountains” (Twisselmann), 761–2,042 m (CCH).

Frangula rubra ssp. rubra (Rhamnus rubra Greene 1887) V. Grubov 1949. Red buckthorn.  Low shrubs <2m; twigs red, leaves 2–6 cm, elliptical to wider below the mid region, acutely angled in lower fourth to petiole; flowering Mar–Jun. Open thickets , 4,000–7,000 ft, Klamath Mts. and Sierra Nevada, southernmost distribution Kern Co.: Piute Mountains, along forest road 29S03 north of Grouse Meadow and about 3 miles south of Claraville, 2,133 m (CCH: Shevock, 8 Aug 1983); Greenhorn Mountains, 2–3 miles southeast of Lumreau Creek crossing at the Mill Creek crossing, near the road from Glennville to the Pettit Ranch and the Davis Ranger Station, 1,402 m (CCH: Charlotte Smith, 15 Jun 1941).