Glossy Buckthorn (Frangula alnus)

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Phylum	Magnoliophyta
Class	Magnoliopsida
Superorder	Rosanae
Order	Rosales
Family	Rhamnaceae
Genus	Frangula

Scientific Name

Frangula alnus

Scientific Name Synonyms

Rhamnus frangula

Common Name

glossy buckthorn

Miller, J.H., E.B, Chambliss, N.J. Loewenstein. 2010. A Field Guide for the Identification of Invasive Plants in Southern Forests. General Technical Report SRS-119. Asheville, NC. United States Department of Agriculture, Forest Service. 126 p.

Plant

Deciduous shrub with many sprouts from the base, or small tree, 6 to 24 feet (12 m) in height, up to 10 inches (25 cm) in diameter with glossy bark (thus the common name), thornless stems and an oval, much-branched crown. Alternate, oval leaves appear early in spring and linger green into fall, dark green and glossy above with distinct parallel lateral veins. Stemmed clusters of tiny white flowers in summer yield spherical, green berrylike fruit that turn red then black in the fall.

Stem

Twigs alternate, initially reddish, and slightly gray fuzzy with scattered white dots (lenticels), becoming hairless and gray to brownish gray with light dots in lengthwise bands that become raised and eventually turn into lengthwise, shallow fissures on larger stems. Buds pointed and fuzzy. Leaf scars raised with 3 bundle scars. Cut twigs have yellow sapwood and pinkish to orange centers.

Leaves

Alternate, tardily deciduous, narrowly elliptic to oblong to obovate, 2 to 4 inches (5 to 10 cm) long and one-half as wide with 8 to 9 pairs of parallel lateral veins curving upward at the ends to follow the margin. Margins entire and somewhat wavy. Shiny green above, paler and slightly hairy beneath, turning greenish yellow in the fall. Petioles reddish and hairy, 0.25 to 0.5 inch (6 to 12 mm) long.

Flowers

May to September. Axillary, stemmed clusters of tiny flowers with 5 whitish petals barely jutting from a bell-shaped green calyx, appearing on new growth after the leaves.

Fruit and seeds

May to November. Berrylike, spherical drupes, 0.3 to 0.4 inch (8 to 12 mm) wide, light green ripening to red then black in late summer, fleshy, containing 2 to 3 ovoid seeds.

Ecology

Tolerant of a wide variety of growing conditions from wet to dry and basic to acidic soils. Persists in shade with rapid growth in full sun to produce seed as early as year 3. Wide spreading with many sprouts, leafing out early in spring and retaining foliage late in fall leading to the exclusion of other forest plants. Abundant seed spread by birds, with seedlings able to establish in shade. Invades forest edges and understories.

Resembles

Resembles the native Carolina buckthorn [Frangula caroliniana (Walt.) Gray], but its leaf margins are finely serrated (serrulate) and leaves are 3 times as long as wide. Also resembles common buckthorn (Rhamnus cathartica L.), another invasive that has finely serrated leaf margins but with 3 to 5 pairs of curved lateral veins, thorn-tipped twigs, only 4 petals, and 3 to 4 seeds. Also resembles the native alderleaf buckthorn (R. alnifolia L’Hér.), a shrub to 6 feet (2 m) tall and wide with crenate-serrate margins, 6 to 9 paired lateral veins, and hairless beneath.

History and use

Initially introduced from Eurasia and North Africa in the mid-1800s as an ornamental.

Distribution

Found as scattered plants or dense infestations in VA, TN, KY, and NC.

Management strategies

Bag and dispose of fruit in a dumpster or burn.
Treatment combinations must be planned and enacted that safeguard adjoining shrubs and overstory trees.
Treat when new plants are young to prevent seed formation.
Manually pull new seedlings and tree wrench saplings when soil is moist, ensuring removal of all roots.
Prescribed burning has limited application in most situations and can worsen infestations.

Recommended control procedures

When safety to surrounding vegetation is desired, thoroughly wet all leaves with a glyphosate herbicide or Garlon 3A as a 2- to 3-percent solution (8 to 12 ounces per 3-gallon mix) in water with a surfactant. Or if nontarget damage is not a concern, apply Arsenal AC* as a 0.25-percent solution (1 ounce per 3-gallon mix) or Arsenal PowerLine* as a 0.5-percent solution (2 ounces per 3-gallon mix). Apply July to October.

For stems too tall for foliar sprays, cut large stems in winter at any time when the ground is not frozen and immediately treat the stump tops with one of the following herbicides: a glyphosate herbicide or Garlon 3A as a 25-percent solution (3 quarts per 3-gallon mix) or Garlon 3A as a 50-percent solution (6 quarts per 3-gallon mix) in water with a surfactant. Or when safety to surrounding plants is not a concern, Tordon RTU*. Roundup Pro, ORTHO Brush-B-Gon, Enforcer Brush Killer, and Vine-X are effective undiluted for treating cut-stumps and available in retail garden stores (safe to surrounding plants). A subsequent foliar application may be required to control new seedlings and resprouts.

For trees up to 4 inches in diameter, apply a basal spray of Garlon 4 as a 20-percent solution (5 pints per 3-gallon mix) in a labeled basal oil product, vegetable oil or mineral oil with a penetrant, fuel oil or diesel fuel (where permitted).

* Nontarget plants may be killed or injured by root uptake.

Images

May	June	June
November	June	January

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