Black Locust aka Flase Acacia, Common Locust, Yellow Locust
Robina pseudoacacia
Classification
- Clade: Eudicots
- Order: Pea
- Family: Pea (Fabaceae)
- Subfamily: Pea (Hedysarum)
- Tribe: Licorice tribe (Galegeae) (Includes Locust Tribe)
Leaf 
- pinnately compound with 9-19 leaflets
- hairless
- oval
- smooth edges
- 20 -30 cm (8-14″)
- leaflets are 2.5 cm long (1.5″)
- notched at apex
- fold during the night
- alternate
Fall Foliage
- yellow
Flower
- typical pea family flowers are irregular with 5 petals named the banner (single petal with 2 lobes), 2 wings, and keel (2 fused together petals)
- 5 united sepals
- racemes (hanging/drooping chain) 12-20 cm in length
- 3/4″ flowers in 8″ clusters/chains
- mid to late June-July
- fragrant
- white
Buds
- naked
- hidden within petiole
Twig
- buds hidden under the leaf scar between spines
- leaf scar has 3 irregular cracks
- paired spines at nodes
- zig-zag
- hairless
- reddish-brown
- pith present
Shoot
- ribbed, grooves
Spines
- most buds have paired spines
Bark
- smooth
- deep grooves/fissures/furrows/forking ridges
- light gray to light brown
- rope-like texture
Branches
- sometimes crooked
Height
- 20-30 m (40-60′)
Crown
- open
- allows passage of light
- rounded
- irregular
Bole
- short
- fluted
Fruit
- pod (legume)
- brown to black
- flat
- splits along a seam when ripe
- straight edges (not curvy/wavy/twisted)
- 4″, most are not over 8″ in length (5-10 cm)
- light
- thin walled
- rounded to pointed at end
- seeds within pod are kidney-shaped (reniform)
- seeds are less than 0.25″ in length
- seeds are reddish-orange
Edible Parts
- some sources report that the seeds are poisonous
- may be edible after boiling
- seeds: acidic, oil rich
- Leaves and bark are poisonous
Habitat
- rocky areas
- sandy areas
- open areas
- woods
Range:
- Eastern United States
- Planted as ornamental in Canadian Maritimes (has naturalized in some areas)
Other Characterisitics
- may form suckers from roots
- rot-resistant wood (fence posts, grapevine stakes, railroad ties)
- introduced to Europe in 1600 (North American Native)