Invasive Buckthorn and Native Look-Alikes

European Buckthorn (green) in late fall
We have two types of invasive Buckthorn in Minnesota. The first (most common) is European Buckthorn (Rhamnus cathartica) and the second is Glossy Buckthorn (Frangula alnus). There are several native trees and shrubs that often get confused with these Buckthorns.



European Buckthorn Leaf
Both of these invasives were introduced as horticultural ornamentals mainly for use as hedging. "European or Common Buckthorn and Glossy Buckthorn or Alder Buckthorn are listed as restricted noxious weeds in Minnesota. It is illegal to import, sell, or transplant buckthorn in Minnesota." (Source: MN DNR)

For comparison purposes, I will highlight leaf shape, color and arrangement, bud, bark, flower and fruit for these Buckthorns and their native look alikes.

LEAF
European Buckthorn Leaf
European Buckthorn ~ Rhamnus cathartica

Shape: Elliptical, often with pronouced point
Edge: Serrated
Leaf Arrangement on Branch:
Varies from opposite to subopposite to alternate
Leaf Stem (Petiole): Hairy
Venation: Parallel curving to leaf point/end, 3-4 veins per leaf half
Color: Dark Green above, light green below
Fall Color: Dark Green
Distinguishing Feature of Leaf: Inconsistent leaf arrangement on branch


Glossy Buckthorn Leaf


Glossy Buckthorn ~ Frangula alnus

Shape: Elliptical, often coming to point
Edge: Smooth
Leaf Arrangement on Branch:
Alternate
Leaf Stem (Petiole): Hairy, reddish-pink
Venation: Parallel curving to leaf point/end, 6-9 veins per leaf half
Color: Dark Green & Glossy above, light green below
Fall Color: Yellow
Distinguishing Feature of Leaf: Non-serrated leaf edge

Native Chokecherry Leaf


Choke Cherry ~ Prunus virginiana
Often Confused with Glossy Buckthorn
Shape: Elliptical, often wider on top half of leaf
Edge: Serrated
Leaf Arrangement on Branch: 
Alternate
Leaf Stem (Petiole): Sometimes hairy
Venation: Parallel tilting upwards to edge, then rounding to a close to vein above
Color: Dark Green above, light green below and hairy
Fall Color: Bright yellow to orange to peachy

Native Black Chokeberry leaf (above)
Red Fall Color (below)


Black Chokeberry ~ Aronia melanocarpa
Often Confused with European Buckthorn
Shape: Elliptical to oblong
Edge: Serrated
Leaf Arrangement on Branch: 
Alternate
Leaf Stem (Petiole): Short, often reddish-pink at base
Venation: Parallel curving towards leaf point/tip

Color: Dark Green above, light green below
Fall Color: Yellow to orange to bright red
Distinguishing Feature: Black 'hair-like' glands on the middle (center) vein


Glands on Center Vein Black Chokeberry



 BUD
European Buckthorn Bud With 'Thorn'
Dark Brown Scales

European Buckthorn Bud 'Hooves' Arrangement
Dark Brown Scales




Glossy Buckthorn Bud
Reddish color, hairy
Choke Cherry Bud
Light Brown Scales, single bud
Chokeberry Bud
Red, pointed
 BARK
0.5" Diameter European Buckthorn
Smooth Gray Bark with White lenticels
Image Source: Chris Evans, Invasive.org 
6" Diameter European Buckthorn
with peeling light brown bark
Black Cherry Bark
Often confused with European Buckthorn
Black Cherry (yellow ribbon) and
European Buckthorn (blue ribbon)

Orange Inner Bark on European Buckthorn
Image Source: Chris Evans, Invasive.org
Choke Cherry Bark
Dark Brown with light brown streaks
1" Diameter Glossy Buckthorn Bark
Light Gray with Yellow-white lenticels
FLOWER
Glossy Buckthorn Flowers
European Buckthorn Flowers
Image Source: Chris Evans, Invasive.org 
Black Chokeberry Flower
Choke Cherry Flower
FRUIT
Black Chokeberry
Unripened Fruit
European Buckthorn
Blue-black ripe Fruit
Black Chokeberry Fruit
Glossy Buckthorn Fruit
Choke Cherry Fruit