Alderleaf Buckthorn

Rhamnus alnifolia
Species distinguishing characteristics: 
  • Shrub found in moist to wet, marshy areas
  • Leaves with 5-8 pairs of parallel leaf veins
  • Young branches have downy hairs
  • Flat-topped clusters of 2-5 greenish-yellow flowers without stalks
  • Bluish-black berry
Family Characteristics: 
  • Shrubs or small trees with undivided alternate leaves 
  • Clusters of small white or greenish flowers in leaf joints or stem tips
  • Flowers have 4-5 sepals and male organs (stamens)
  • Disk-shaped flowers attached by short-stalks or stalkless
  • Fruit is a juicy berry or a 3 (sometimes 2 or 4) celled capsule
  • Grooved, thin-coated seeds
Growth habitat: 

Erect or spreading shrub, up to 2.5 m tall.

Leaves and stems: 

Alternate leaves, 3-10 cm, attached by short stalks, have an egg-shape, a pointed tip, and small rounded teeth on edges.  Leaves have 5-8 pairs of prominent parallel leaf veins.

Bark: 

Young branches have fine, downy grey hair, but become hairless and dark grayish-brown with age.

 

Flowers: 

Separate plants contain male or female flowers.  Flat-topped stalkless clusters of 2-5 greenish-yellow flowers, 5 mm wide, in lower leaf joints.  Cupped flowers have 5 sepals and no petals.

Alderleaf Buckthorn flower clusters by Rebecca Durham
Alderleaf Buckthorn flower clusters by Rebecca Durham
Seeds: 

Bluish-black berry (reddish when unripe), 6-9 mm, with 3 flat, hard-coated seeds inside the thick, juicy flesh.

Habitat preferences: 

Moist to wet forests, thickets, marshy areas, lakes, streambanks, and wet meadows at mid-elevations.

Interesting facts: 

The bark (and to a lesser degree the berries) of alderleaf buckthorn has strong laxative effects and can induce vomiting in cases of poisoning.  The bark of its relative cascara false buckthorn (Rhamnus purshiana) is more commonly used as tea, liquid extract, or dried and powdered.  Alderleaf buckthorn is potent and may cause cramping.  This strong medicine should be cured and dried for at least 1 year before use, and used with caution.

Biological Classification: