American Witch Hazel

With October nearly over, temperatures are starting to dip. The asters and goldenrods have traded their floral displays for their wind-dispersed seeds that take advantage of the fall breeze. Alas, floral displays in the northern hemisphere are nearly over. There is one major show left for those living in eastern North America. From October through November (and even into December in some regions) one species of understory shrub puts forth a display reminiscent of a firework extravaganza if the fireworks only came in yellow.

I am, of course, talking about American witch hazel (Hamamelis virginiana). This wonderful shade-loving shrub goes largely unnoticed throughout the summer. Come fall, however, it makes up for its subtle appearance by offering up some of the last flowers of the season. Seemingly overnight their branches become adorned with unique little flowers whose petals shoot out like four little party streamers. They somehow manage to look both modest and showy all at once.

It may seem strange for any plant to be flowering so late. What possible advantage could this entail? Some experts believe that late flowering evolved as a way for American witch hazel to avoid competition with other flowering plants. Indeed, it certainly attracts its fair share of pollinators in desperate search of a late season meal. Flies and bees make up a majority of pollinator visits. It could also be possible that American witch hazel flowers so late to avoid hybridizing with its spring-flowering cousin, the Ozark witch hazel (Hamamelis vernalis). Regardless of its "intentions," this fall flowering strategy comes at a cost.

Despite garnishing a fair amount of pollinator attention, American witch hazel doesn't have enough time following pollination to produce fruit before winter hits. As such, fertilization of the ovaries is delayed until May the following year. The fruits, which are contained in woody capsules, spend the entire growing season maturing into viable propagules. Once mature, the seed capsules begin to dry until they become so taught that the capsule bursts. If you are lucky and attentive enough, you may be able to hear a small snap as the seeds are forcibly ejected from the capsule.

What's more, fruit set in this species is rather low. Analyses of over 40,000 witch hazel flowers showed that less than 1% produced viable seeds. Despite all of this, American witch hazel is nonetheless a successful species in eastern North American forests. It is proof that evolution need not be all or nothing. Any slight advantage is still an advantage. This hardy shrub is, at the end of the day, a survivor.

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