Scientific Name:
Robinia pseudoacacia
Pronunciation:
roe-BIN-ee-uh soo-doe-ah-KAY-see-uh
Common Name:
black locust
Family Name:
Fabaceae
Plant Type:
Tree - deciduous
Key ID Features:
Leaves pinnately compound, most 10-30 cm long x 5-10cm wide, (3-)7-15(-23) leaflets, most oblong, 2-4cm long x 1-1.5cm wide, spiney stipules; golden-yellow (cv. Frisia) or bronze-green (cv. Purple Robe); florets 10-20 in pendant racemes, wisteria-like, 10-20cm long, florets pea-likem white or violet-purple, fragrant; legumes smooth, flat, 5-11cm long, purple-brown. Winter ID: bark longitudinally fissured on older trees or rarely smooth, twigs zig-zag, groved, pair of spiney stipules 0.5-2cm long at (some) nodes, buds tiny, terminal bud absent.
Habit:
Arching, Open, Twiggy, Upright
Form:
Columnar, Oval - vertical
Texture:
Medium - fine
Mature Height:
10 - 15m
Mature Spread:
7 - 10m
Growth Rate:
Moderate
Origin:
Garden origin, U.S. - central, U.S. - northeast
Hardiness Rating:
Zone 4: (-34 to -29 °C)
Exposure:
Full sun
Soil/Growing Medium:
Rocky or gravelly or dry, Well-drained
Water Use:
Low
Landscape Uses:
Erosion control, Reclamation, Shade tree, Specimen plant, Street (boulevard tree), Summer interest, Tall background, Woodland margin (Caution: poisonous parts)
Additional Info:
Leaf Morphology:
Form:
Compound
Arrangement:
Alternate
Texture/Venation:
Soft flexible, Pinnate venation
Surfaces:
Glabrous
Compound Leaf:
Odd-pinnate
Colour in Summer:
Green, Green-yellow
Colour in Fall:
Yellow
Shapes:
Elliptic, Oblong, Ovate
Apices:
Acute, Rounded
Bases:
Rounded
Margins:
Entire
Additional Info:
Spectacular fall colour
Inflorescence Type:
Raceme, Floriferous
Flower Morphology:
Flowers perfect
Number Of Petals:
5
Corolla Shape:
Bilabiate
Ovary Position:
Superior
Colour (petals):
Showy, White, Purple
Flower Scent:
Fragrant
Flower Time at Peak:
May, Jun
Fruit Type:
Legume
Fruit Colour:
Purple, Brown, Black
Fruiting Time:
Aug, Sep
Additional Info:
Not showy, Persistent, pods may be seedless
Bark Morphology:
Lightly fissured, Deeply fissured
Bark or Stem Colour:
Dark Grey, Brown
Leaf Bud Type:
Rounded or globular
Leaf Scar Shape:
Three-lobed
Organ Modifications:
Root nodules (N-fixing), Stipule, pointy spines, Species may send out root suckers
Propagation:
Cuttings
Pest Susceptibility:
Beetles or weevils, Fungal leaf spot, Leaf miner insect, Mildew, Wilt (Pest resistant, Disease resistant)
Course(s):
- HORT 1155
- HORT 2355
- Level 1 Apprenticeship
Location(s):
- (WDH) Wark-Dumais House : cvs. Frisia (q.2) and Purple Robe