Frangula alnus
Common name: 
Alder Buckthorn
Glossy Buckthorn
Breaking Buckthorn
(NOT Alderleaf Buckthorn (Rhramnus alnifolia)
FRANG-gew-la al-NUS
Rhamnus frangula
Native to (or naturalized in) Oregon: 
  • Broadleaf deciduous shrub or low-branching tree, upright, spreading, as a shrub 15 ft (4.5 ft) tall with an equal width, tree form may reach 20 ft (6 m) tall; not thorny.  Leaves alternate, simple, 3-7 cm long, oval, obovate to obovate-oblong, tip acute, base rounded or broad wedge-shaped, margin entire, dark glossy green above and lighter green and sometimes pubescent below, 8-9 pairs of veins; petiole 6-12 mm long; fall color varies from pale greenish yellow to reddish.  Flowers prefect, creamy-green, 5-parted, 2-10 per axillary cluster, not showy; attracts bees.  Fruit globose, 6 mm across, red ripening to dark purple, 2-3 seeded.
  • Sun or shade, best in well-drained soil
  • Hardy to USDA Zone 3     Native to Europe, western Asia and North Africa.  
  • Alder buckthorn was first formally described by Carl Linnaeus in 1753 as Rhamnus frangula. It was subsequently separated by Phillip Miller in 1768 into the genus Frangula on the basis of its hermaphrodite flowers with a five-parted corolla (in Rhamnus the flowers are dioecious and four-parted), and it is now designated Fangula alnus.  Although much disputed historically, the separation of Frangula from Rhamnus is now widely accepted, being supported by recent genetic data, though a few authorities still retain the genus as Rhamnus (e.g. the Flora of China)(Wikipedia).  Nurseries will likely continue to list this plant as Rhamnus frangula for some time to come.
  • Considered to be the most ornamental of the buckthorns.   Some argue that Frangula alnus has limited value in the landscape because it is weedy and prone to self-seed.  Indeed, it is listed as an invasive species in some areas (as are many introduced buckthorns), and reportedly is very aggressive in wet, forested locations.  "Its wood makes the best charcoal for gunpowder" (Hillier, 1998, p.466).
  • Some of the selections available:
    • ‘Asplenifolia’ -- leaves of about regular length but only about 3-5 mm wide, fern-like.
    • ‘Columnaris’   (syn. ‘Tallhedge') -- compact, narrow, upright form, prized for hedges.
    • FineLine®  (syn. ‘Ron Williams') -- upright, columnar habit, leaves linear (~15 × 6 cm), undulate, deeply cut, feathery foliage is medium green, turns yellow in fall.  Derived from a cross of ‘Columnaris’ (female) and ‘Asplenifolia’ (male) ; reportedly has low seed set and seed is not viable, hence not a potential weed or invasive threat. PP14,791
  • alnus: the genus of alders (Alnus), apparently this, and its Alder Buckthorn common name, refer to its association with alders on damp sites


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