Common Name: Alder Buckthorn

General Information

Frangula alnus is a tall deciduous shrub or small tree with an erect, slender habit; it usually grows around 4 - 5 metres tall but occasionally reaches 7 metres[].
The plant was at one time frequently cultivated as a source of wood for making charcoal and for its medicinal bark, though now it is restricted mainly to wild collection for more local use. It is sometimes grown as an ornamental, and is often grown for making native hedges and shelterbelts[].
Frangula alnus has an exceptionally large range, occurring in many European, west Asian, Middle-Eastern, and Northern African countries. It does not appear to be in decline from any threatening processes at present, except in Northern Ireland and in the outermost parts of its range in Spain. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].
The species was introduced to North America before 1800 and has since escaped from cultivation in many areas and become established in the wild. Once established, Frangula alnus shades out native understorey plants and it maintains itself through its prolific seed production, vigorous growth over an extended growing season and its ability to regenerate following burning and cutting. These aggressive characteristics make it difficult to eradicate, especially in wetlands[, ].

Known Hazards

The plant is poisonous unless stored for 12 months before use[, , ]. This report is probably referring to the bark.
Species in this genus contain hydroxyanthracene derivatives which have a stimulant laxative effect upon the body, and many species are used traditionally as laxatives. In small doses, and for short periods, these can be safe and effective, but used over long periods they can weaken the body's natural ability to defecate and can have a range of long-lasting negative effects upon the body, including anaemia, malabsorption, haematuria and weight loss. Large single doses can cause severe purging.

Botanical References

, , ,

Range

Eurasia - throughout Europe, east to Eastern Siberia, Western China (Xinjiang), Iran and Iraq; N. Africa - Morocco, Tunisia, Algeria

Habitat

Swamps and damp places, usually on moist heaths and damp open woods, preferring a peaty soil; at elevations up to 1,300 metres[, , , ].

Properties

Conservation Status	Least Concern
Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	5.00 m
Growth Rate	Slow
Pollinators	Bees, Wasps, Flies, Beetles
Self-fertile	No
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Frangula alnus is a very cold-hardy plant, able to tolerate temperatures down to around -35°c when fully dormant[].
An easily grown plant, it succeeds in any reasonably good soil[, ], preferring neutral to acid conditions[]. It grows well on damp or peaty soils[]. Prefers a moist moderately fertile soil in sun or semi-shade[]. Grows well in wet soils but not if they are water-logged[]. Dislikes drought or exposure to strong winds[].
Alder buckthorn is a slow-growing plant, though it coppices well. It was at one time often grown for its wood which was used in making charcoal[]. The plants regenerate well after forest fires or grazing[].
Plants flower on one-year old wood and also on the current year's growth[].
Cultivated as a medicinal plant in S. Europe[].
This species often bears the aecidospore stage of 'crown rust' of oats[].
The species in this genus are notably resistant to honey fungus[].
A good bee plant[] and a main food plant for the larvae of the yellow brimstone butterfly[].

Edible Uses

None known

Medicinal

Alder buckthorn has been used medicinally as a gentle laxative since at least the Middle Ages[]. The bark contains 3 - 7% anthraquinones, these act on the wall of the colon stimulating a bowel movement approximately 8 - 12 hours after ingestion[]. It is so gentle and effective a treatment when prescribed in the correct dosages that it is completely safe to use for children and pregnant women[]. The bark also contains anthrones and anthranols, these induce vomiting but the severity of their effect is greatly reduced after the bark has been dried and stored for a long time[]. The bark is harvested in early summer from the young trunk and moderately sized branches, it must then be dried and stored for at least 12 months before being used[, ]

The inner bark is cathartic, cholagogue, laxative (the fresh bark is violently purgative), tonic, vermifuge[, , , , ]. It is taken internally as a laxative for chronic atonic constipation and is also used to treat abdominal bloating, hepatitis, cirrhosis, jaundice, and liver and gall bladder complaints[]. It should be used with caution since excess doses or using the bark before it is cured can cause violent purging[, ].
Externally, the bark is used to treat gum diseases and scalp infestations[], or as a lotion for minor skin irritations[].

The fruit is occasionally used, it is aperient without being irritating[].

Agroforestry Uses:

Plants can be grown as an informal (untrimmed) hedge, though they are also amenable to trimming[]. The cultivar 'Tallhedge (syn 'Columnaris') is very suitable for this purpose[].
The flowers are a good forage for bees[].

Other Uses

A yellow dye is obtained from the leaves and bark[, ]. It is much used in Russia and turns black when mixed with salts of iron[].
A green or yellow dye is obtained from the unripe fruit[, , ].
A blue or grey dye is obtained from the ripe berries[, ]. Dyes obtained from the ripe fruits stain cottons green and woollens violet[].

The pale-orange wood is soft. It is used to make wooden nails, shoe lasts, veneer etc[, , ].
The wood is the source of a high quality, almost ash-free charcoal that is used by artists and for making gunpowder[, , , , , , , , ].

Propagation

Seed - best sown in the autumn in a cold frame. Stored seed will require 1 - 2 months cold stratification at about 5° and should be sown as early in the year as possible in a cold frame or outdoor seedbed[]. Germination is usually good, at least 80% by late spring. Prick out the seedlings into individual pots when they are large enough to handle, and grow them on in the greenhouse or cold frame for their first winter. Plant them out in late spring or early summer of the following year.
Cuttings of half-ripe wood, mid summer in a frame[].
Cuttings of mature wood of the current year's growth, autumn in a frame.
Layering in early spring[].