Cascara buckthorn

Silhouette - cascara buckthorn
  • Latin name: Rhamnus purshiana D.C.
  • French name: Nerprun cascara
  • Synonym(s): Cascara
  • Taxonomic Serial Number: 28582
    506987 (Frangula purshiana (DC.) Cooper)
Description

Leaves

  • Leaf with detail of finely toothed margin - cascara buckthorn

Form

  • Alternate (occasionally opposite)
  • Usually widest just above the middle
  • Tip short or blunt, base rounded
  • Lower surface slightly hairy
  • Veins very prominent, 10–15 pairs
  • Young trees may retain green leaves into winter

Length

  • 4–16 cm

Margin

  • Finely and evenly toothed

Buds

  • Lateral bud and leaf scar - cascara buckthorn

Form

  • Very small, without scales
  • Hairy, usually in 4 rows along the twig
  • Terminal bud present

Twigs

  • Winter twig - cascara buckthorn

Form

  • Slender, hairy, becoming smooth
  • Bitter tasting
  • Leaf scars crescent-shaped, raised with a few scattered vein scars

Colour

  • Yellowish-green becoming reddish-brown

Flowers

Form

  • Inconspicuous

Colour

  • Yellowish-green

Structure

  • Polygamo-monoecious

Floral timing

  • June

Fruits

  • Fruit (left); seed (right) - cascara buckthorn

Form

  • Berry-like, rounded
  • Containing 2–3 small nutlets

Width

  • 8–14 mm

Colour

  • Blackish

Bark

Form

  • Thin, smooth, becoming scaly with age

Colour

  • Dark greyish-brown

Wood

Texture

  • Light, soft

Colour

  • Brown, tinged with red

Morphology

  • Close-grained
  • Diffuse-porous, pores visible with a hand lens
  • Annual rings and rays visible to the naked eye

Size

Height

  • To 6 m

Diameter

  • To 25 cm
  • Occasionally larger

Tree form

  • Silhouette - cascara buckthorn

Forest–grown

Trunk

  • Slender
  • On young trees, dividing into ascending branches

Crown

  • On older trees, horizontal branches form a compact, irregular crown

Habitat

Site

  • Moist organic soils
  • Coarse, sandy or gravelly soils

Associated species

  • Alders and birches (on burned-over areas and clearings)
  • An understory tree in conifer forests
Photos
  • Cascara buckthorn
Distribution map
Distribution map - cascara buckthorn
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