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Robinia pseudoacacia is often confused with:
Gleditsia triacanthos var. inermis Tree
Robinia hispida Form in June
Zabelia tyaihyoni Zabelia tyaihyoni
Plants that fill a similar niche:
Prunus americana Prunus americana
Tilia americana Tilia americana
Prunus caroliniana Carolina Cherry Laurel Flowers
Robinia pseudoacacia has some common insect problems:
Locust Borer

Green Locust Robinia pseudoacacia

Phonetic Spelling
roh-BIN-ee-ah soo-doh-ah-KAY-see-ah
This plant has high severity poison characteristics.
See below
Description

Robinia pseudoacacia, or Black Locust, is a deciduous, flowering tree that may grow 50 to 70 feet tall and a trunk diameter of 3 to 4 feet. It is a native forest tree in the mountains of North Carolina, however, it is widely planted throughout the state and is now naturalized to all soil and water conditions, except for saturated soils. In other parts of the state, Black Locust can be found in thickets on clay banks or waste areas or along fence rows. It is a relatively short-lived tree with about a 90 year life span.

The leaves are alternate, pinnately compound with 7 to 21 leaflets. The bark is gray or light brown, thick, fibrous, heavily ridged, and furrowed. In spring and early summer, fragrant, pea-like white flowers, borne in long (5 inch) hanging clusters mature. The tree produces a 2 to 4 inch flattened legume which contains 4 to 8 red-brown seeds.

Black Locust grows in a variety of soil types and has the ability to fix nitrogen in the soil, so it is sometimes used to reclaim soil banks in abandoned sites. This is a good plant for difficult sites, transplants well, and tends to reseed.  It develops shoots from roots.  It is also a legume, fixes its own nitrogen and is moderately salt tolerant. Species trees are sometimes considered to be somewhat weedy. Trees send out long underground root suckers that not only become a maintenance problem but also can disrupt nearby gardening areas. Robinia pseudoacacia can be pruned and kept at shrub size by cutting them to the ground every 2-3 years, but pruning should be avoided in the spring as the tree will bleed. This tree is not usually recommended for the landscape because it tends to be invasive, is thorny, and has brittle branches that can break off in the wind.

Insects, Diseases, or Other Plant Problems:  

It is susceptible to locust borer (often fatal) and locust leaf miner (browns foliage). Other insect problems include caterpillars, weevils, scale and whiteflies. Possible disease problems include canker, powdery mildew, leaf spots, wood rots and verticillium wilt. Small branches of the Black locust fall easily during storms.  Some of its leaves yellow and fall off during times of drought.

See this plant in the following landscape:
Cultivars / Varieties:
  • 'Frisia'
    Golden yellow leaves in the fall.
  • 'Lace Lady'
    Eight to ten feet high, smaller spines, but does not produce flowers.
  • 'Purple Robe'
    Compact and rounded with rose-pink flowers.
  • 'Tortuosa'
    Slow growing and compact, but fewer and smaller flowers.
  • 'Umbraculifera'
    Attractive leaves, thornless, but rarely flowers.
'Frisia', 'Lace Lady', 'Purple Robe', 'Tortuosa', 'Umbraculifera'
Tags:
#thorns#showy flowers#deciduous#invasive#poisonous#fragrant flowers#white flowers#wildlife plants#native tree#salt tolerant#cover plant#spring flowers#wetlands#food source wildlife#fast growing#low flammability#NC native#fire resistant#pollinator plant#Braham Arboretum#poor soils tolerant#larval host plant#food source summer#food source fall#food source herbage#food source nectar#food source pollen#coastal UPL#bird friendly#food source hard mast fruit#mammals#butterfly friendly#Piedmont Mountains FACU#problem for cats#pollinator garden#problem for dogs#bee friendly#problem for children#problem for horses#audubon#silver-spotted skipper butterfly#clouded sulphur butterfly#zarucco duskywing butterfly
 
Cultivars / Varieties:
  • 'Frisia'
    Golden yellow leaves in the fall.
  • 'Lace Lady'
    Eight to ten feet high, smaller spines, but does not produce flowers.
  • 'Purple Robe'
    Compact and rounded with rose-pink flowers.
  • 'Tortuosa'
    Slow growing and compact, but fewer and smaller flowers.
  • 'Umbraculifera'
    Attractive leaves, thornless, but rarely flowers.
'Frisia', 'Lace Lady', 'Purple Robe', 'Tortuosa', 'Umbraculifera'
Tags:
#thorns#showy flowers#deciduous#invasive#poisonous#fragrant flowers#white flowers#wildlife plants#native tree#salt tolerant#cover plant#spring flowers#wetlands#food source wildlife#fast growing#low flammability#NC native#fire resistant#pollinator plant#Braham Arboretum#poor soils tolerant#larval host plant#food source summer#food source fall#food source herbage#food source nectar#food source pollen#coastal UPL#bird friendly#food source hard mast fruit#mammals#butterfly friendly#Piedmont Mountains FACU#problem for cats#pollinator garden#problem for dogs#bee friendly#problem for children#problem for horses#audubon#silver-spotted skipper butterfly#clouded sulphur butterfly#zarucco duskywing butterfly
  • Attributes:
    Genus:
    Robinia
    Species:
    pseudoacacia
    Family:
    Fabaceae
    Uses (Ethnobotany):
    The wood from this native is yellow, coarse grained, hard, strong, and naturally rot resistant and is often used to make fence posts and rails, mine timbers, and landscaping ties.
    Life Cycle:
    Woody
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    Eastern and central United States
    Distribution:
    Appalachian and Ozark mountain ranges, but now naturalized and found in all 48 states of the contiguous United States.
    Fire Risk Rating:
    low flammability
    Wildlife Value:
    This is a larval host plant for several butterflies. Clouded Sulphur (Colias philodice) larvae appear from May to October in the north and from March to November in the south. There are 3 flights in the north and 4 to 5 flights in the south (but it rarely uses this plant as a host in North Carolina). Zarucco Duskywing (Erynnis zarucco) has three broods in the deep south from March-October, appearing as early as January in Florida. Silver-Spotted Skipper (Epargyreus clarus) appears from May-September with three-four broods in the deep south, two broods in the east, and one brood in the north and west. The buds and catkins are eaten by birds.  It provides an excellent leaf cover for birds in wetland sites.   Bees are attracted to its flowers and rabbits depend on the sprouts and seeds during the winter.
    Play Value:
    Fragrance
    Wildlife Food Source
    Particularly Resistant To (Insects/Diseases/Other Problems):
    Fire in the landscape. Heat and drought tolerant.
    Edibility:
    All parts of the tree are considered toxic. The toxins are destroyed by heat.
    Dimensions:
    Height: 50 ft. 0 in. - 70 ft. 0 in.
    Width: 20 ft. 0 in. - 35 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Native Plant
    Poisonous
    Tree
    Woody Plant Leaf Characteristics:
    Deciduous
    Habit/Form:
    Erect
    Oval
    Rounded
    Growth Rate:
    Rapid
    Maintenance:
    Medium
    Texture:
    Medium
    Appendage:
    Spines
    Thorns
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    Clay
    High Organic Matter
    Loam (Silt)
    Sand
    Soil pH:
    Acid (<6.0)
    Alkaline (>8.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Moist
    Occasionally Dry
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    3b, 3a, 4b, 4a, 5b, 5a, 6a, 6b, 7a, 7b, 8a, 8b, 9b, 9a
  • Fruit:
    Fruit Color:
    Brown/Copper
    Purple/Lavender
    Display/Harvest Time:
    Fall
    Fruit Type:
    Legume
    Fruit Length:
    > 3 inches
    Fruit Description:
    The flowers are followed by smooth, flat, purple-brown,flat, seed pods (to 4 to 5 inches long) each bearing 4 to 8 kidney-shaped seeds. These display from July to November and the pods can persist on the tree through the winter.
  • Flowers:
    Flower Color:
    White
    Flower Inflorescence:
    Raceme
    Flower Value To Gardener:
    Fragrant
    Showy
    Flower Bloom Time:
    Spring
    Summer
    Flower Shape:
    Lipped
    Flower Petals:
    fused petals
    Flower Description:
    Fragrant wisteria-like white flowers in pendant racemes (to 8 inches long) bloom from April to June. They are pea-like and very fragrant.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Blue
    Brown/Copper
    Green
    Leaf Value To Gardener:
    Showy
    Deciduous Leaf Fall Color:
    Gold/Yellow
    Leaf Type:
    Compound (Pinnately , Bipinnately, Palmately)
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Ovate
    Leaf Margin:
    Entire
    Hairs Present:
    No
    Leaf Length:
    > 6 inches
    Leaf Width:
    > 6 inches
    Leaf Description:
    The leaf of the Black locust is noted for its attractive alternate, compound leaves and pendant racemes of pea-like flowers. It has pinnate dark blue-green leaves, 8 to 14 inches long, with each leaf having up to 23 lance-shaped to ovate leaflets. Leaves turn uneventful yellow in fall.
  • Bark:
    Bark Color:
    Black
    Dark Brown
    Light Brown
    Surface/Attachment:
    Furrowed
    Ridges
    Scaly
    Bark Description:
    Deeply furrowed and scaley.
  • Stem:
    Stem Is Aromatic:
    No
    Stem Cross Section:
    Round
    Stem Surface:
    Smooth (glabrous)
    Stem Description:
    Its branches are usually armed with short paired spines (to 1.25 inches long) adjacent to each leaf scar.
  • Landscape:
    Landscape Location:
    Naturalized Area
    Recreational Play Area
    Landscape Theme:
    Butterfly Garden
    Native Garden
    Pollinator Garden
    Design Feature:
    Flowering Tree
    Attracts:
    Bees
    Butterflies
    Hummingbirds
    Pollinators
    Small Mammals
    Songbirds
    Resistance To Challenges:
    Black Walnut
    Drought
    Dry Soil
    Fire
    Pollution
    Poor Soil
    Salt
    Problems:
    Poisonous to Humans
    Problem for Cats
    Problem for Children
    Problem for Dogs
    Problem for Horses
  • Poisonous to Humans:
    Poison Severity:
    High
    Poison Symptoms:
    If ingested, it may cause death in humans and livestock and pets. Depression, weakness, dilated pupils, vomiting, bloody diarrhea, weak pulse, coldness of arms and legs, paleness, and shock.
    Poison Toxic Principle:
    Robin, a phytotoxin; robitin, a glycoside; robinine, an alkaloid.
    Causes Contact Dermatitis:
    No
    Poison Part:
    Bark
    Leaves
    Seeds