Data provided by the participants of the Consortium of California Herbaria

View additional distribution information on the Jepson eflora

Rhamnus purshiana (Cascara Buckthorn, Cascara, Bearberry, and in the Chinook Jargon, Chittam or Chitticum; syn. Frangula purshiana, Rhamnus purshianus) is a species of buckthorn native to western North America from southern British Columbia south to central California, and inland to western Montana. It is the largest species of buckthorn, occasionally growing up to 15 meter tall, though more commonly a large shrub or small tree 5-10 meter tall, with a trunk 20-50 centimeter in diameter. The bark is brownish to silver-grey with light splotching. The leaves are deciduous, alternate, clustered near the ends of twigs; they are oval, 5-15 centimeter long and 2-5 centimeter broad with a 0.6-2 centimeter petiole, dark shiny green on top, fuzzy and paler green below. The flowers are tiny, 4-5 millimeter diameter, with five greenish yellow petals; the flowering season is brief, disappearing by early summer. The fruit is a berry 6-10 millimeter diameter, bright red at first, quickly maturing deep purple or black, and containing three seeds.

Plant type

Shrub

Size

20 - 49 ft Tall
12 ft Wide

Form

Upright

Growth rate

Slow

Dormancy

Winter Deciduous

Calscape icon
Color

White, Green, Yellow

Flowering season

Spring

Special uses

Bank stabilization

Sun

Partial Shade, Full Sun

Water

Low

Summer irrigation

Max 3x / month once established

Cold tolerance

Tolerates cold to 0° F

Soil drainage

Fast, Medium, Slow, Standing

Soil description

Quite adaptable to a wide variety of soil types.
Soil PH: 4 - 7

Propagation

Propagate from seeds (3 month stratification) or by cuttings taken from half-ripe to mature wood in late summer or fall.

Sunset Zones

1, 2, 3, 4*, 5*, 6*, 7, 14, 15*, 16*, 17*

Site type

Varied, but generally in low-montana forested areas in moist canyons, swamps, and bottomlands.

Plant communities

Chaparral

Other plants of western coniferous forest understories such as Red Alder (Alus Rubra), Vine Maple (Acer circinatum), Redosier Dogwood (Cornus sericea), and Orange Honeysuckle (Lonicera ciliosa).

Bats
Birds
Bees
Caterpillars
Butterflies

Butterflies and moths supported

8 confirmed and 27 likely

Confirmed Likely

Eupithecia columbiata

Tamarack Looper

Eupithecia misturata

Green Pug

Eupithecia ravocostaliata

Hesperumia latipennis