Common Name: New Mexico Locust

General Information

Robinia neomexicana is a spiny, deciduous shrub or small tree with a dense crown; it can grow from 1 - 8 metres tall. The bole can be 15 - 30cm in diameter.The plant suckers freely and can form dense thickets[, ].
The plant is harvested from the wild for local use as a food, medicine and source of materials. It is used in soil stabilization projects and is grown as an ornamental.
Robinia neomexicana has a wide distribution range and at present there are no major known threats causing a population decline. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

The bark, root and seed are said to be poisonous[]. The roots, leaves and bark contain robinin and are very poisonous.

Botanical References

, ,

Range

South-western N. America - California to Wyoming, south to Arizona, Texas and northern Mexico (Sonora),

Habitat

Common in canyons, along streams or arroyos, on terraces, talus slopes, and in coniferous forest understories, growing on gentle to relatively steep slopes on all aspects; at elevations from 1,219 - 2,789 metres[]

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	2.00 m
Pollinators	Insects
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Robinia neomexicana occurs in semiarid continental climates with dry warm springs, hot moist summers, and cold moist winters[]. When fully dormant, it can tolerate temperatures down to around -20°c[]. Across its range, two major precipitation seasons exist, with 35 - 42% of precipitation falling as rain in July and August. Mean annual precipitation ranges from 380 - 760mm[].
Succeeds in a hot dry position. Succeeds in any soil, preferring one that is not too rich[, ]. Plants are found on a wide variety of soils in the wild, ranging from clays to sandy loams derived from volcanic or limestone parent materials[]. Requires a well-drained soil, succeeding on dry barren sites[]. Plants are tolerant of drought and atmospheric pollution[].
The branches are brittle and very liable to wind damage[]. When plants are grown in rich soils they produce coarse and rank growth which is even more liable to wind damage[, ].
The tree's thin bark and moderate litter production probably make it susceptible to fire. Although top growth is liable to be killed, the tree usually regenerates from the base. In addition, the plant's succulent foliage during the summer decreases the severity of fires[].
Plants can be coppiced[].
Any pruning should be done in late summer in order to reduce the risk of bleeding[].
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

Flowers - raw or cooked[, , , , ]. They can be used as a flavouring in cooked dishes[]. The flowers can be boiled, then dried and stored for later use[].

Seedpods - raw or cooked[, ]. They are gathered in the fall and eaten when fresh[]. The pods can also be cooked then dried and stored for later use[]. The hairy seedpod is around 75mm long, containing several small seeds[].

Seed - cooked[, ].

Medicinal

Antirheumatic[, ].

An emetic (part not specified, but likely to be the root bark[]), it is used to clear the stomach[, ].

Agroforestry Uses:

Plants fix atmospheric nitrogen and succeed in dry barren sites, whilst their suckering habit makes them suitable for stabilizing banks[, ]. They have been recommended for use in erosion control projects on sites at elevations from 150 - 1,800 metres, with deep soil and in full sun[].
Frequently grown as a hedge plant is SW USA.
The plant can be used as a pioneer species when restoring native woodland. In the wild it often becomes dominant around 3 years after removal of the tree canopy, eventually being shaded out 15 - 20 years later when new-growth conifers overtop it[].
The flowers are a rich source of nectar for bees.

Other Uses

The heartwood is yellow streaked with brown; the sapwood is light yellow. The wood is close-grained with a satiny texture, tough, very hard, heavy, elastic and durable[, , , ]. It is of little value for timber because of its small size and limited distribution, but is used for fence posts etc[, ].
The wood is used for fuel[].

Propagation

Seed - pre-soak for 48 hours in warm water and sow the seed in late winter in a cold frame[]. A short stratification improves germination rates and time[]. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in the following summer. The seed stores for over 10 years[].
Suckers taken during the dormant season.