Common Name: Green Osier

General Information

Cornus alternifolia is a deciduous shrub, sometimes producing a cluster of erect stems, or a small tree that usually grows up to 6 metres tall, occasionally to 12 metres. As the tree ages it develops a distinctive horizontal branching pattern[, , ].
The tree is harvested from the wild for local use as a medicine and source of materials. It is sometimes grown as an ornamental.

Known Hazards

None known

Botanical References

, ,

Range

Eastern N. America - Manitoba to Newfoundland, south to Arkansas, Missisippi and Florida.

Habitat

Deciduous hardwood forests, usually mesic or dry-mesic, loamy soils, rocky slopes; at elevations from 10 - 2,000 metres[]. Rich woodlands and forest margins in moist well-drained soils[].

Properties

Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	6.00 m
Growth Rate	Fast
Pollinators	Insects
Cultivation Status	Ornamental, Wild

Cultivation Details

Cornus alternifolia is a very cold-hardy plant, tolerating temperatures down to about -25°c when dormant. In order to thrive, however, it also needs warm, sunny summers and is often a failure when grown in areas with cool summers, even if the winters are mild[, ].
Succeeds in full sun or light shade[[]. An easily grown plant, it succeeds in any well-drained soil of good or moderate fertility[, ], ranging from acid to shallow chalk[]. Grows well in heavy clay soils and in dry soils.
A fast-growing but short-lived species in the wild[], it is closely related to Cornus controversa[].
Plants start flowering when around 2 metres tall[].
This species is unusual in having alternate leaves whilst almost all other members of this genus have opposite leaves[].
Plants have a thin bark and this makes them susceptible to forest fires[].
There is at least one named form selected for its ornamental value[].
Plants in this genus are notably resistant to honey fungus[].

Edible Uses

The blue, globose fruit is 5 - 8mm in diameter; it has a thin layer of flesh enclosing a single, large seed[]. We have not seen any reports of it being edible.

Medicinal

Green osier was employed medicinally by a number of native North American Indian tribes who valued it particularly for its astringent bark which was used both internally and externally to treat diarrhoea, skin problems etc[]. It is little used in modern herbalism.

The dried bark is used as an astringent, diaphoretic and stimulant[, ]. The inner bark was boiled and the solution used as an enema[] and this solution was also used as a tea to reduce fevers, treat influenza, diarrhoea, headaches, voice loss etc[, ]. It was used as a wash for the eyes[].

A compound infusion of the bark and roots has been used to treat childhood diseases such as measles and worms[]. It has also been used as a wash on areas of the body affected by venereal disease[].

A poultice of the powdered bark has been used to treat swellings, blisters etc[].

The fresh fruits contain 16.67g per kilo of bioactive anthocyanins which makes them an excellent source of these compounds[]. Anthocyanins have a range of positive actions in the body, including antiinflammatory and antioxidant. The anthocyanins in Cornus alternifolia have potential for use in the treatment of various complaints including cancer[]

Other Uses

A light to dark-brown dye is obtained from the roots with the addition of vinegar[].

The wood is heavy, hard, close grained. It is too small to be of commercial value, but is used locally for turnery[, ].

Propagation

Seed - best sown as soon as it is ripe in a cold frame or in an outdoors seedbed if there is sufficient seed[, ]. The seed must be separated from the fruit flesh since this contains germination inhibitors[, ]. Stored seed should be cold stratified for 3 - 4 months and sown as early as possible in the year[]. Scarification may also help as may a period of warm stratification before the cold stratification[, ]. Germination, especially of stored seed, can be very slow, taking 18 months or more[]. Prick out the seedlings of cold-frame sown seeds into individual pots as soon as they are large enough to handle and grow the plants on for their first winter in a greenhouse, planting out in the spring after the last expected frosts.
Cuttings of half-ripe side shoots, mid summer in a frame.
Cuttings of mature wood of the current year's growth, taken with a heel if possible, autumn in a cold frame. High percentage[].
Layering of new growth in early summer/July. Takes 9 months[].