Corylus cornuta

Corylus cornuta is grown commercially for its edible nuts. Wildlife and birds utilize much of this plant for food.
Photo Credit: © William S. Justice. Courtesy of Smithsonian Institution, Dept. of Systematic Biology, Botany.
Corylus cornuta
Common Name: beaked hazelnut
Plant Functional Group: Deciduous broadleaf
Class > Order > Family: Magnoliopsida > Fagales > Betulaceae
What does the species look like?

Beaked hazelnut is a deciduous shrub to small tree growing 3 to 49 feet tall, with plants forming thickets connected by underground roots. Male and female flowers are separate on the same plant. The tiny, inconspicuous male and female flowers are grouped into clusters. The many male flowers are grouped into long, yellow-brown, caterpillar-like clusters (catkins), and the several female flowers are enclosed by a scaly bract, showing bright red flower parts when receptive. One-year-old sprouts will produce male flowers; two-year-old sprouts will also produce female flowers. Flowers are pollinated by wind.

Beaked hazelnut grows in mesic and/or lightly shaded sites on well-drained soils (sands, sandy loams, and gravels in its western-most distribution, and loam and loamy sands in other places); on moist sites in its southern and western-most distributions, and generally preferring dry-mesic soils in other areas. It occurs along forest edges and openings; in thickets, coves, canyons, and old fields; and on rocky slopes, wooded hillsides, and streambanks. Plants growing in heavy shade may not flower or fruit, and germination and establishment rates are also reduced.
Where is the species found?
States & Provinces
AB, AL, BC, CA, CO, CT, DE, GA, IA, ID, IL, MA, MB, MD, ME, MI, MN, MT, NB, NC, ND, NH, NJ, NL, NS, NY, OH, ON, OR, PA, PE, QC, RI, SC, SD, SK, TN, VA, VT, WA, WI, WV, WY
Special Considerations for Observing

If drought seems to be the cause of leaf color or fall for a plant, please make a comment about it for that observation.
Which phenophases should I observe?
Do you see...?
Leaves Breaking leaf buds
One or more breaking leaf buds are visible on the plant. A leaf bud is considered "breaking" once a green leaf tip is visible at the end of the bud, but before the first leaf from the bud has unfolded to expose the leaf base at its point of attachment to the leaf stalk (petiole) or stem.
More...

How many buds are breaking?

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000
Leaves
One or more live, unfolded leaves are visible on the plant. A leaf is considered "unfolded" once its entire length has emerged from a breaking bud, stem node or growing stem tip, so that the leaf base is visible at its point of attachment to the leaf stalk (petiole) or stem. Do not include fully dried or dead leaves.
More...

What percentage of the potential canopy space is full with leaves? Ignore dead branches in your estimate of potential canopy space.

  • Less than 5%
  • 5-24%
  • 25-49%
  • 50-74%
  • 75-94%
  • 95% or more
Increasing leaf size
A majority of leaves on the plant have not yet reached their full size and are still growing larger. Do not include new leaves that continue to emerge at the ends of elongating stems throughout the growing season.
More...

What percentage of full size are most leaves?

  • Less than 25%
  • 25-49%
  • 50-74%
  • 75-94%
  • 95% or more
Colored leaves
One or more leaves show some of their typical late-season color, or yellow or brown due to drought or other stresses. Do not include small spots of color due to minor leaf damage, or dieback on branches that have broken. Do not include fully dried or dead leaves that remain on the plant.
More...

What percentage of the potential canopy space is full with non-green leaf color? Ignore dead branches in your estimate of potential canopy space.

  • Less than 5%
  • 5-24%
  • 25-49%
  • 50-74%
  • 75-94%
  • 95% or more
Falling leaves
One or more leaves with typical late-season color, or yellow or brown due to other stresses, are falling or have recently fallen from the plant. Do not include fully dried or dead leaves that remain on the plant for many days before falling.
More...


Flowers Flowers or flower buds
One or more fresh open or unopened flowers or flower buds are visible on the plant. Include flower buds or inflorescences that are swelling or expanding, but do not include those that are tightly closed and not actively growing (dormant). Also do not include wilted or dried flowers. For Corylus cornuta, the male inflorescence is a catkin which is initially compact and stiff, but eventually unfolds to become longer and hang loosely from the branch. Female flowers are very small and petal-less, emerging from buds on the twig.
More...

How many flowers and flower buds are present? For species in which individual flowers are clustered in flower heads, spikes or catkins (inflorescences), simply estimate the number of flower heads, spikes or catkins and not the number of individual flowers.

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000
Open flowers
One or more open, fresh flowers are visible on the plant. Flowers are considered "open" when the reproductive parts (male stamens or female pistils) are visible between or within unfolded or open flower parts (petals, floral tubes or sepals). Do not include wilted or dried flowers. For Corylus cornuta, the male flowers will open once the initially compact catkin has unfolded and is hanging loosely. Female flowers are open when the tuft of red pistils is visible.
More...

What percentage of all fresh flowers (buds plus unopened plus open) on the plant are open? For species in which individual flowers are clustered in flower heads, spikes or catkins (inflorescences), estimate the percentage of all individual flowers that are open.

  • Less than 5%
  • 5-24%
  • 25-49%
  • 50-74%
  • 75-94%
  • 95% or more
Pollen release
One or more flowers on the plant release visible pollen grains when gently shaken or blown into your palm or onto a dark surface.
More...

How much pollen is released?

  • Little: Only a few grains are released.
  • Some: Many grains are released.
  • Lots: A layer of pollen covers your palm, or a cloud of pollen can be seen in the air when the wind blows

Fruits Fruits
One or more fruits are visible on the plant. For Corylus cornuta, the fruit is a nut hidden by a long, fuzzy, tubular husk that changes from green to brown.
More...

How many fruits are present?

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000
Ripe fruits
One or more ripe fruits are visible on the plant. For Corylus cornuta, a fruit is considered ripe when both the nut and the husk are brown.
More...

What percentage of all fruits (unripe plus ripe) on the plant are ripe?

  • Less than 5%
  • 5-24%
  • 25-49%
  • 50-74%
  • 75-94%
  • 95% or more
Recent fruit or seed drop
One or more mature fruits or seeds have dropped or been removed from the plant since your last visit. Do not include obviously immature fruits that have dropped before ripening, such as in a heavy rain or wind, or empty fruits that had long ago dropped all of their seeds but remained on the plant.
More...

How many mature fruits have dropped seeds or have completely dropped or been removed from the plant since your last visit?

  • Less than 3
  • 3 to 10
  • 11 to 100
  • 101 to 1,000
  • 1,001 to 10,000
  • More than 10,000
What do these phenophases look like?

There is currently no photoguide available for this species. If you'd like help us create one, use the guidance document and species template provided here. Then send it via email to education@usanpn.org when it is complete.

USDA PLANTS profile for beaked hazelnut (USDA Symbol: COCO6 )