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