Quercus phellos
Common name: 
Willow Oak
KWER-kus FEL-os
Native to (or naturalized in) Oregon: 
  • Broadleaf deciduous tree, 50-60 ft (15-18 m), excurrent (ie., prolonged main axis from which lateral branches arise), oblong oval crown, fairly open (light shade), descending branches, (growth habit similar to a pin oak); stems slender, reddish-brown to dark brown.  Leaves alternate, simple, 5-13 cm long, narrow (0.8-2.5 cm wide), elliptical or lance-shaped (willow-like), wavy entire margin.  Autumn color yellow or russet red to red.  The species is monoecious, producing separate male (staminate) and female (pistillate) flowers on the same tree.  Male flowers are produced in drooping yellowish catkins about 5-7.5 cm (2-3 inches) long.  Female flowers are inconspicuous appear in groups of 2-3 near the tips of twigs, developing into small acorns, about 1.5 cm or less.
  • Sun, transplants easier than other oaks, has a fibrous root system.  Prefers moist well-drained soil but can adapt to difficult habitats.
  • Hardy to USDA Zone 5      Native range from New York to Florida, west to Missouri and Texas.
  • phellos: according to Jacobson (1996) the term is an ancient Greek name for the cork oak (Q. suber), and for some reason Linnaeus applied it to this species.
  • Corvallis: a row of them north of the Osborn Aquatic Center, Circle Ave. and Highland St.
  • Oregon State Univ. Campus: southwest corner Dixon Recreation Center
Click image to enlarge
  • male catkins and expanding leaves

    male catkins and expanding leaves

  • plant habit

    plant habit

  • foliage


  • leafy shoot

    leafy shoot

  • leaves


  • plant habit, fall

    plant habit, fall

  • branches, fall

    branches, fall

  • branches, fall

    branches, fall

  • leaves, fall

    leaves, fall

  • plant habit, spring (61 years-old)

    plant habit, spring (61 years-old)

  • trunk (61 years-old)

    trunk (61 years-old)

  • trunk, bark

    trunk, bark

  • winter twigs and buds

    winter twigs and buds