Gleditsia caspica

Desf.

Caspian locust

Fabaceae Edible: Seeds 43 iNaturalist observations

iNaturalist· cc-by-nc

Summary

Gleditsia caspica, the Caspian locust or Persian honeylocust, is a species of Gleditsia native to western Asia, in the Caucasus region of Azerbaijan and northern Iran, close to the Caspian Sea. It is a medium-sized deciduous tree growing to 12 m tall, with the trunk covered in numerous, 10–20 cm long branched spines. The leaves are pinnate or bipinnate, up to 25 cm long, with 12–20 leaflets; bipinnate leaves have six to eight pinnae. The leaflets are up to 5 cm long and 2 cm broad. The flowers are greenish, produced in racemes up to 10 cm long. The fruit is a pod 20 cm long and 3 cm broad. It is closely related to Gleditsia japonica (syn. G. horrida) from eastern Asia, and is treated as a subspecies of it by some botanists, Gleditsia horrida subsp. caspica (Desf.) J.Paclt.

Description

A deciduous tree. It grows 12 m tall. It has branching thorns. These can be 15 cm long. The flowers are small and green. They are densely packed in downy clusters along a stalk. The fruit is a curved pod. It is thin. The pods can be 20 cm long.

Edible Uses

The seeds of several species in this genus can be eaten raw or cooked. This species often crops well and would be worth researching further for its edibility potential.

Medicinal Uses

None known

Distribution

It suits hardiness zones 6-10.

Where It Grows

Australia, Iran, Middle East, Transcaucasia,

Cultivation

Easily grown in a loamy soil, requiring a sunny position. Succeeds in most soils including sandy ones. Established plants tolerate drought and atmospheric pollution. This species is often confused in cultivation with the closely related G. sinensis, many of the trees grown under that name are this species. This tree is remarkable for the number and length of the spines growing on its trunk, which makes it the most formidably armed of temperate trees. Trees have a light canopy, they come into leaf late in the spring and drop their leaves in early autumn making them an excellent top storey tree in a woodland garden. 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.

Propagation

Pre-soak seed for 24 hours in warm water, then sow in spring in a greenhouse. The seed should have swollen; if not, soak for another 24 hours. If soaking alone fails, carefully file away part of the seed coat without damaging the embryo, then soak again until the seed swells. Once swollen, germination takes 2–4 weeks at 20°C. Prick seedlings into individual deep pots as soon as they are large enough to handle, and plant out into permanent positions in summer. Provide some protection from cold during the first few winters outdoors.

Other Uses

The closely related G. sinensis has a saponaceous pulp inside the seed pod that can be used as a soap substitute, and it is quite probable this species can be used similarly. The wood is strong, durable, and coarse-grained. This plant also fixes nitrogen.

Notes

There are about 14 Gleditsia species. Also as Caesalpinaceae.

References (4)

Cundall, P., (ed.), 2004, Gardening Australia: flora: the gardener's bible. ABC Books. p 641
Etherington, K., & Imwold, D., (Eds), 2001, Botanica's Trees & Shrubs. The illustrated A-Z of over 8500 trees and shrubs. Random House, Australia. p 346
Hist. arbr. France 2:247. 1809
Plants for a Future database, The Field, Penpol, Lostwithiel, Cornwall, PL22 0NG, UK. http://www.scs.leeds.ac.uk/pfaf/