Latin Name: Gleditsia triacanthos
Family: Fabaceae or Caesalpiniaceae.
Known Hazards: The plant contains potentially toxic compounds.
Habitat: Usually growing singly, though occasionally forming almost pure woods, on the borders of streams and in rich woods. Usually in moist fertile soils but sometimes on dry sterile gravelly hills.
Edibility Rating: 3 (1-5)
Medicinal Rating: 2 (1-5)
Physical Characteristics: Deciduous spreading tree to 25 m high. Leaves to 20 cm long, leaflets elliptic to ovate, hairless, sparsely toothed. Seedpod slightly sickle-shaped, compressed, not opening at maturity, with seeds surrounded by a sweet pulp. Seeds flattened, ovoid, brown, about 10 mm long.
In axillary racemes to 10 cm long, in most cases male and female flowers are on different plants but some plants have bisexual flowers. Sepals and petals similar, brownish-yellow, 3–5 of each. Flowers spring, either as leaves develop or after leaves appear. The flowers are hermaphrodite (has both male and female organs) and are pollinated by Insects.
Distinguishing features: Distinguished by simple or branched spines 2–18 cm long (some cultivars are spineless but some of their offspring are spiny); leaves pinnate or bipinnate, leaflets in 5 to 30 pairs, 1–4 cm long, 0.4–1.2 cm wide; sepals to 4 mm long, petals to 6 mm long, stamens 5–7; seedpod to 45 cm long, 15–30 seeded.
Seed; Seedpod. Seed – raw or cooked. It can contain up to 30% sugar. Young seeds taste like raw peas. Seeds are not always borne in maritime regions because the tree prefers long hot summers. The oval seeds are about 8mm long. They contain 10.6 – 24.1% protein, 0.8 – 4.3% fat, 84.7% carbohydrate, 21.1% fibre, 4% ash, 280mg calcium and 320mg phosphorus per 100g. The seeds have been roasted and used as a coffee substitute. Seedpods – the pulp is sweet and can be eaten raw or made into sugar. The render young seedpods can be cooked and eaten. The pulp in older pods turns bitter. The seedpods are up to 40cm long and 4cm wide. A sweet, pleasant tasting drink can be made from the seed pods. The seed pulp has been used to make a drink.
Anaesthetic; Antiseptic; Cancer; Stomachic. The pods have been made into a tea for the treatment of indigestion, measles, catarrh etc. The juice of the pods is antiseptic. The pods have been seen as a good antidote for children’s complaints. The alcoholic extract of the fruits of the honey locust, after elimination of tannin, considerably retarded the growth, up to 63% of Ehrlich mouse carcinoma. However, the cytotoxicity of the extract was quite high and the animals, besides losing weight, showed dystrophic changes in their liver and spleen. The alcoholic extract of the fruit exerted moderate oncostatic activity against sarcoma 180 and Ehrlich carcinoma at the total dose 350 mg/kg/body weight/mouse. Weight loss was considerable. An infusion of the bark has been drunk and used as a wash in the treatment of dyspepsia. It has also been used in the treatment of whooping cough, measles, smallpox etc. The twigs and the leaves contain the alkaloids gleditschine and stenocarpine. Stenocarpine has been used as a local anaesthetic whilst gleditschine causes stupor and loss of reflex activity. Current research is examining the leaves as a potential source of anticancer compounds.
Gum; Soil reclamation; Tannin; Wood. Planted for land reclamation on mining waste. The gum from the seeds has been suggested as an emulsifying substitute for acacia and tragacanth. The heartwood contains 4 – 4.8% tannin. Wood – strong, coarse-grained, elastic, very hard, very durable in contact with the soil, highly shock resistant. It does not shrink much but splits rather easily and does not glue well. It weighs 42lb per cubic foot. Largely used for making fence posts and rails, wheel hubs, farm implements etc and in construction.
Notes: Introduced as a fodder tree and cultivated as an ornamental. Pods are first produced when trees are 3–5 years old. Trunk is protected by thorns. Found in dense thickets along watercourses on the central coast, western slopes and tablelands of northern NSW and in south eastern Queensland. Introduced by William Macarthur to ‘Camden Park’, Camden NSW in mid 1800s and now widespread on the floodplain of the Hawkesbury-Nepean river system.