Yesterday, I posted about one of the few plants that I know of that flowers before the vernal equinox. But I wanted to dedicate today’s post to the only plant I know of that is native to northeastern North America and flowers in the middle of winter.
This is Witch Hazel (Hamamelis virginiana):
Witch Hazel is fascinating for a number of reasons. It produces an astringent which has cytotoxic properties active against certain cancers, and used for acne. It was also used to make divining rods (supposedly to find water), but there’s no scientific support for that.
It has these crazy flowers with long yellow ribbons, and tiny red sepals, that appear in the middle of winter…technically, they flower from September through November, but in urban areas, I’ve seen flowers on them in February during a snow storm.
The name means “together fruit”, which is descriptive of the flowers being present at the same time as the fruit of the previous year. Indeed, although the flowers are pollinated in the fall, fertilization does not occur until months after. Here’s a quote from Shoemaker (On the Development of Hamamelis virginiana, 1905): “Fertilization takes place in May, five to seven months after pollination.”
But there is little else flowering when Witch Hazel is flowering, and that makes it a mystery. For example, this species depends on insect vectors for pollination, but there are not many insects flying around in November! Its habit of flowering when through hard frosts and even snow seems odd, and suggests that the benefits of high fidelity visitation outweigh the costs of low frequency visitation.
Naturally, my question was “What pollinates the Witch Hazel flowers?” The answer seems to be mainly flies, and mainly a tiny fungus gnat (Anderson & Hill 2002): “A species of dark-winged fungus gnat in the genus Bradysia constituted 42% of all flies collected.“
In other words, because Witch Hazel is the only thing flowering, it is also pretty much the only pollen that insect vectors can be carrying, so every pollen transfer is sure to be the right species. There is some evidence that this lack of “pollen interference” could be advantageous.
The real clue comes from comparing the flowering of this species with its closely related cousins. Here’s an explanation from Shoemaker (1905): “In comparing Hamamelis virginiana with its relatives, it seems certain that it was once a spring-flowering plant, whose blossoming has worked backward through the winter.”
What a fascinating plant!