Frangula alnus Mill.

European buckthorn, alder buckthorn

About plant names...

Alder buckthorn is native to Europe, Africa, and Asia. It was introduced to North America, where it has become naturalized. Frangula means "brittle wood," and alnus means alders, which are often found in the same habitats. Alder buckthorn actually has no thorns, though relatives in the Rhamnus genus often do. In many areas it is considered an invasive.

Identification: This shrub reaches 9½-20' (3-6 m). It usually has multiple stems, rarely only one, becoming a tree. Dark brown-black bark covers a light yellow interior bark. Leaves are roughly oval, 1-2½" (3-7 cm) long and ⅞-1½" (2.5-4 cm) wide. Leaves have prominent veins and stems ¼-½" (8-15 mm) long. Flowers are ¹/₁₆-³/₁₆" (3-5 mm), 5-petaled, yellowish- or greenish-white, and inconspicuous. Clusters of shiny black berries, reddish or purplish before ripening, are each ⅛-⅜" (6-10 mm) in diameter.

9/7/2013 · Beech Hill, Dublin, New Hamp­shire
≈ 8 × 5" (19 × 12 cm)

7/20/2012 · J. Harry Rich Dirt Road, Groton, Mass­a­chu­setts
≈ 7 × 4½" (17 × 11 cm)

Here are some similar-looking buckthorns:

	Rhamnus alnifolia	Rhamnus cathartica	You are here Frangula alnus
Common Name	alderleaf buckthorn	buckthorn	European buckthorn
Plant	This smaller shrub reaches up to 3' (1 m) in height.	Plants are rounded shrubs or small trees up to 33' (10 m) in height, with trunks that sometimes reach 10" (25 cm) in width. Outer bark is dark gray, while the inner bark is yellow and the heartwood is pink to orange in color. Stem tips are often tipped with a spine.	9½-20' (3-6 m) tall. It usually has multiple stems, rarely only one, becoming a tree. Dark brown-black bark covers a light yellow interior bark.
Flowers	Yellowish-green, 5-petaled, in groups of 1-3, nestled at the base of leaves, from May to July. Male and female flowers are on different plants.	Yellowish-green, with four petals, in dense clusters.	¹/₁₆-³/₁₆" (3-5 mm), 5-petaled, yellowish- or greenish-white, and inconspicuous.
Leaves	Alternate, elliptical, either rounded or pointed at the tip, smooth-edged, up to 4" (10 cm) × 2" (5 cm).	Elliptic (roughly oval), with several prominent veins roughly parallel to the leaf edges and fine teeth. They are ⅞-3½" (2.5-9 cm) × ⅜-1¼" (1.2-3.5 cm) in size. Leaves are mostly opposite, occasionally alternate, smooth on top and bottom.	Roughly oval, 1-2½" (3-7 cm) long and ⅞-1½" (2.5-4 cm) wide. Leaves have smooth edges and prominent veins and stems ¼-½" (8-15 mm) long.
Fruit	Round, up to ¼" (6.3 mm) in diameter, turning to light red and then to deep black. Each fruit contains three seeds.	Fruits are dense clusters of black berries ⅛-⅜" (6-10 mm) in diameter. Each berry contains 3-4 seeds.	Clusters of shiny black berries, reddish or purplish before ripening, are each ⅛-⅜" (6-10 mm) in diameter.
Range/ Zones
Type	Wild	Wild	Wild
Occurrence	Uncommon	Common	Common

Online References:

Wikipedia

The USDA Forest Service's Fire Effects Information Database

Invasive.org, Center for Invasive Species and Ecosystem Health

Plants for a Future, a resource and information centre for edible and otherwise useful plants

Harvard Forest

Wikimedia Commons

The Ecology of Commanster

References:

Petrides, George A., Peterson Field Guides: Trees and Shrubs, Houghton Mifflin Co., 1972, p. 267

7/7/2012 · Gibbet Hill, Groton, Mass­a­chu­setts
≈ 9 × 6" (22 × 14 cm)

6/23/2012 · Nashua River Rail Trail, East Pepperell, Pepperell, Mass­a­chu­setts
≈ 4½ × 3" (11 × 7.9 cm)

9/7/2013 · Beech Hill, Dublin, New Hamp­shire
≈ 8 × 5" (19 × 12 cm)

7/20/2012 · J. Harry Rich Dirt Road, Groton, Mass­a­chu­setts
≈ 8 × 5" (19 × 13 cm)

7/5/2012 · Groton Place and Sabine Woods, Groton, Mass­a­chu­setts
≈ 7 × 4½" (17 × 11 cm)

9/7/2013 · Beech Hill, Dublin, New Hamp­shire
≈ 8 × 5" (19 × 12 cm)

6/16/2010 · Nashua River Rail Trail, Groton Center, Groton, Mass­a­chu­setts
≈ 9 × 6" (22 × 14 cm)

6/23/2013 · Rocky Ridge Trail, Beaver Brook Conservation Area, Hollis, New Hamp­shire
≈ 6 × 4" (16 × 10 cm)

6/23/2012 · Nashua River Rail Trail, East Pepperell, Pepperell, Mass­a­chu­setts
≈ 2½ × 2½" (6.9 × 6.6 cm)

Frangula alnus description by Thomas H. Kent, last updated 11 Oct 2021.

© FloraFinder.org. All rights reserved.

6/23/2012 · Nashua River Rail Trail, East Pepperell, Pepperell, Mass­a­chu­setts
≈ 7 × 4½" (17 × 11 cm)

6/20/2012 · Nashua River Rail Trail, Groton Center, Groton, Mass­a­chu­setts
≈ 9 × 6" (22 × 14 cm)

7/27/2009 · Nashua River Rail Trail, Groton, Mass­a­chu­setts
≈ 13 × 9" (33 × 22 cm)

8/4/2009 · Near Nashoba Hospital, Ayer, Mass­a­chu­setts
≈ 12 × 8" (30 × 20 cm)

8/6/2009 · Nashua River Rail Trail, Groton, Mass­a­chu­setts
≈ 4 × 2½" (10 × 7.2 cm)

7/7/2012 · Gibbet Hill, Groton, Mass­a­chu­setts
≈ 6 × 4" (15 × 10 cm)

7/5/2012 · Groton Place and Sabine Woods, Groton, Mass­a­chu­setts
≈ 6 × 4" (15 × 10 cm)

9/7/2013 · Beech Hill, Dublin, New Hamp­shire
≈ 5 × 8" (12 × 19 cm)

6/24/2015 · Nashua River Rail Trail, Groton Ctr, Groton, Mass­a­chu­setts
≈ 6 × 6" (14 × 14 cm)

6/24/2015 · Nashua River Rail Trail, Groton Ctr, Groton, Mass­a­chu­setts
≈ 8 × 6" (20 × 14 cm)

Range:

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