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Black Locust

Purple Robe

Catalogue A#2004-009  Z16

GPS  45D 43' 56" N  / 108D 37' 15" W



Robinia ambigua 'Idahoensis' 'Purple Robe', Robinia pseudoacacia

Family: Fabaceae (Leguminosae)

Origin: North America

Common Name: Purple Robe Locust

Location: Plaza-East side pathway just before brick walkway

Number in accession: 1

This specimen has survived whereas others planted in the past (in different areas) have not

overallbenefitsFRPE13Park or other vacan

​This 13 inch Black locust provides overall benefits of: $109 every year. 

​Black locusts have invasive traits that enable them to spread aggressively. While these trees have demonstrated invasive traits, there is insufficient supporting research to declare them so pervasive that they cannot be recommended for any planting sites. Review of risks should be undertaken before selecting these trees for planting sites. Black locust produces hanging clusters of very fragrant white flowers in spring. This fast-growing native tree can form colonies and has brittle wood. Sharp spines may be present, especially on sucker growth. They are also susceptible to locust borers.

Tree or Plant Type: Tree
        Foliage: Deciduous (seasonally loses leaves)
        Native Locale:  North America
        Size Range: Large tree (more than 40 feet), Medium tree (25-40 feet)
Mature Height: 30-50 feet
Mature Width: 20-35 feet
        Light Exposure: Full sun (6 hrs direct light daily), Partial sun/shade (4-6 hrs light daily)
        Hardiness Zones: Zone 4, Zone 5 , Zone 6, Zone 7, Zone 8
        Soil Preference: Moist, well-drained soil
        Acid Soils: Tolerant
        Alkaline Soils: Tolerant
        Salt Spray: Tolerant
        Soil Salt: Tolerant
        Drought Conditions: Tolerant
        Poor Drainage: Intolerant
        Planting Considerations: Aggressive, Excessive sucker growth, Highly susceptible to ice damage, Messy fruit/plant parts, Weak wood and branch structure
        Ornamental Interest: Spring blossoms, Fragrant flowers, Persistent fruit/seeds, Showy flowers, Attractive bark
        Season of Interest: Late spring
        Flower Color & Fragrance: Fragrant, White
        Shape or Form: Oval, Thicket-forming
        Growth Rate: Fast
        Transplants Well: Yes
        Wildlife: Insect pollinator

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