Return to Native Trees of the Southern Rocky Mountains

There are three kinds of Hawthorn trees native to Colorado, all growing as shrubs or small trees with white flowers, reddish fruit, and thorns, in mountain canyons, valleys, and on stream banks, on sites from 5000 to 8500 feet in elevation.

The Hawthorns are quick to reproduce but slow-growing. The maximum height is 20 feet or a little more. Hawthorns often grow in tangled masses in stream bottoms, and birds prefer them for nesting sites. The fruit is eaten by birds, foxes, rabbits, and deer. The thorns are more common on young growth; large older branches have few thorns. This may be an adaptation to provide more protection for the smaller plants.

The tree-sized Hawthorns of Colorado are:

River Hawthorn, Crataegus rivularis.
A shrub or small tree of northwestern Colorado, the San Luis Valley and North Park, and the most common Hawthorn of western slope streams. Thorns few, slender, about an inch long, black, curled, and glossy. Leaves about an inch wide and two inches long, very finely and sharply toothed. Fruits red to dark red or black and to 2/5 inch in diameter.

Shiny-leaved, Cerro, or red-based Hawthorn Crataegus erythropoda.
Usually found on dry hillsides and canyons of the eastern slope up to 8000 feet, and widely distributed in the western counties. Flowers and fruits in a raceme: along a single strand. Fruits dark reddish-purple, brown, or black, 1/4 inch long, and hard.; thorns morocco-red, about an inch long, sometimes short or lacking. Twigs are light orange-brown. Bark has light orange-brown areas. Leaves shiny and slightly lobed;

Western big-thorn Hawthorn Crataegus macracantha var. occidentalis.
Thorns over 1 1/2 inch long; brown or orange-brown. Fruits bright red. Flowers and fruit in a flat-topped cluster. Usually found close to streams on the outermost eastern foothills of the Rockies and widely scattered on the western slope.

The name Crataegus is from the ancient Greek kratos for strength, and refers to the wood which is hard and suitable for making small tough objects such as walking sticks. Other shrubby Hawthorn grow in Colorado but do not reach tree size (species succulenta, saligna, and chrysocarpa).

Leaves: oval, elliptical, or lance-shaped; alternate; toothed; lobed ends, dark green. Leaf stalk length 2/5 to 1 1/4 inch long. Small black dots on edge of leaves.

Fruit: 1/5 to 2/5 inch in diameter; red to reddish purple or black.

Stems: sometimes glossy brown or yellowish, tough, zig-zag.

Thorns: sharp, without buds attached. 3/4 to 3 inches in length; red or black.

Flowers: abundant, appear at end of twigs, 5 petals, white or pink.

Bark: dark red or shiny red, to brown or gray, scaly or with shallow furrows.