Fraxinus quadrangulata
Common name: 
Blue Ash
Pronunciation: 
FRAK-si-nus kwa-drang-u-LA-ta
Family: 
Oleaceae
Genus: 
Type: 
Broadleaf
Native to (or naturalized in) Oregon: 
No
  • Broadleaf deciduous tree, 50-70 ft (15-21 m) high, slow growing, narrow, rounded crown, often irregular; stems 4-sided, with 4 conspicuous ridges or wings.  Leaves opposite, pinnate compound, 17-35 cm long, 5-11 leaflets, each leaflet 5-12 cm long and 2.5-5 cm wide, ovate to lanceolate, short stalked, tip acuminate, base wedge-shaped or rounded, sharply serrate, glossy dark green above, lighter below and pubescent along lower veins and midrib near base.  Flowers perfect (bisexual), purplish.  Fruit (samara) wings oblong, 2.5-5 cm long, 0.8-1.2 cm wide.
  • Sun.  Will grow in doughty soils and alkaline conditions.
  • Hardy to USDA Zone 4   Native from southern Ontario to Michigan to Arkansas and Tennessee.   The inner bark turns blue when exposed; a blue dye is obtained by macerating the inner bark in water.
  • quadrangulata: with four angles., a reference to the four-angled appearance of the stems.
  • Oregon State Univ. campus: north of Kelley Engineering Center in a parking lot island.
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  • plant habit

    plant habit

  • leaf

    leaf

  • leaf

    leaf

  • leaflet, underside

    leaflet, underside

  • trunk, bark

    trunk, bark

  • winter twigs, buds, stems

    winter twigs, buds, stems