Species of the Month: American Witch Hazel
One of Ontario’s most beautiful native shrubs is American Witch Hazel (Hamamelis virginiana). Witch Hazel shrubs are widespread in Norfolk County, commonly found in the understories of moist upland forests and Oak Woodland-Savannas. Witch Hazels obtained their name due to their superficial similarity to Hazels (Corylus sp.), which has similar foliage, and growth form. In early American folklore, Witch Hazels were considered to be at a location of an underground water source – one interpretation of how these shrubs obtained the name “Witch”, named after the practice of water witching or dousing.
In the spring and summer months, identification of Witch Hazel shrubs is best achieved by leaf shape, and growth form. Witch Hazel shrubs have oval-shaped leaves with rounded teeth (edges). Considering the growth form, Witch Hazel usually occurs as an understory shrub with an asymmetrical crown, usually slightly above human reach. Witch Hazel shrubs are much smaller than canopy trees, such as Sugar Maple (A. saccharum) and Tuliptree (Liriodendron tulipifera), with a mature height usually between 3-10 meters. Saplings are small but abundant, and clonal colonies are produced through root suckering. Often, a Witch Hazel plant will have 2 or 3 stems.
Witch Hazel stands out for its unique blooming period, being the sole native shrub in Ontario that flowers in the fall. Around the time the leaves start turning color, the yellow flowers will emerge on Witch Hazel shrubs. These flowers are long-lived, lasting through November – typically pollinated by flies.
After pollination, fruit and seed development is delayed until spring. The spherical fruit capsule, which is wood-like in texture, ripens in late-summer. When the seeds have ripened sufficiently, the fruit capsule opens, ejecting oval black seeds up to 15m from the parent shrub.
In Norfolk County, Witch Hazel shares its habitat with many other shrubs of mesic and dry forests; these include Alternate-leaved (Pagoda) Dogwood (Cornus alternifolia), Flowering Dogwood (Cornus florida), Grey Dogwood (Cornus racemosa), Red Elderberry (Sambucus racemosa), Blue-Beech (Carpinus caroliniana), American Hazel (Corylus americana), Spicebush (Lindera benzoin), Chokecherry (Prunus virginiana) and Viburnum species.
Witch Hazel is one of the many species of native plants that show an Eastern North America – East Asia floristic disjunction. This describes a biogeographic pattern where a plant genus is found in Eastern North America and East Asia (specifically, Japan, Korea and adjacent areas), but is not found elsewhere in the Northern Hemisphere. This floristic disjunction is partially attributable to glaciations in the Pleistocene epoch (“Ice Age”), which wiped out Hickories and Tulip Trees in Europe, but not in North America. There are many native species in Norfolk that show this biogeographical disjunction. There are only 4 other species of Witch Hazel in the world, all of these blooming in early spring (February-March), rather than late autumn. These are the Japanese Witch Hazel (H. japonica), Chinese Witch Hazel (H. mollis), Ozark Witch Hazel (H. vernalis), and Bigleaf Witch Hazel (H. ovalis), with the latter two species from the southeastern U.S.
The leaves, bark, and twigs of this plant are utilized for various medicinal purposes, such as treating diseases, acting as an anti-inflammatory, and helping with complications during pregnancy.
Written By:
Matthew Palarchio, Honour’s BSc in Environmental Science candidate, Western University
