Common Name: Bladder Senna

General Information

Colutea arborescens is a vigorous, much-branched deciduous shrub that can grow up to 3.6 metres tall[].
The plant is harvested from the wild for local use as a medicine and has potential for use as a bio-fuel. Its extensive root system makes it useful in soil stabilization and it is also sometimes grown as an ornamental, where it can be used as a hedge. There are some named varieties.

Known Hazards

The seed is poisonous[, ].

Botanical References

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Range

Southern and central Europe - Germany, France and Spain east to Romania, Bulgaria and Greece

Habitat

Open woods, roadsides, railway banks etc[], often on calcareous soils[].

Properties

Medicinal Rating
Other Uses Rating
Habit	Deciduous Shrub
Height	3.60 m
Growth Rate	Fast
Pollinators	Bees
Cultivation Status	Ornamental, Wild

Cultivation Details

Colutea arborescens is fairly cold-hardy, tolerating temperatures down to about -20°c when dormant[, ].
An easily grown plant, it prefers a well-drained soil and a position in full sun, though it tolerates light shade, and can tolerate most soil conditions other than a water-logged soil[, ]. It grows well on dry sunny banks[, ]. It dislikes strong winds, though another report in the same book says that it it is suitable for maritime plantings (with their salt-laden winds)[]. In our experience the plants are very subject to wind-rock when grown in a windy site[]. Tolerates atmospheric pollution[, ]. A fast growing plant, thriving on poor soils[, ].
Slugs love the young seedlings[].
A group of plants can be kept to a neat shape and convenient size by pruning back the shoots almost to the old wood every winter[]. The flowers are produced on the current season's growth[, ]. These flowers are very attractive to bees[].
The plant usually produces seed abundantly[].
The most distinctive character of the genus is the large, thin-walled, inflated pod, which, when half ripe, may be made to burst with a miniature report when squeezed[].
Plants in this genus are notably resistant to honey fungus[].
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[].

Edible Uses

None known

Medicinal

The leaves are diuretic and purgative[, ]. The leaves are sometimes used as a substitute for senna as a laxative, though they are much milder in their action[]. The plant is rather unreliable when used medicinally so is rarely employed in herbalism[].

The seeds are emetic[]. They are also toxic[].

Agroforestry Uses:

The plants have an extensive root system and are used to stabilize banks and prevent soil erosion[].
The plant responds well to trimming and can be grown as a hedge[, ].

Other Uses

A non-edible oil obtained from the seed is a suitable source for the production of biodiesel[].

Propagation

Seed - pre-soak for 24 hours in hot water and sow late winter in a greenhouse[]. Scarification can help speed up the germination process[]. Germination can be slow and erratic[], though treated seed usually germinates in 1 - 3 months at 20°c[]. As soon as they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out in late spring or early summer, after the last expected frosts.
Cuttings of half-ripe wood, 7 - 10cm with a heel, mid summer in a frame[]. Cuttings are not very long-lived[].