After enduring chiggers, ticks and mosquitoes all summer, fall promises outdoor activities free of itchy and painful natural nuisances. We outdoor lovers look forward to walking through forests and fields without any nasty critters jumping on us.
Every fall, we stroll confidently in comfort until we feel a maddening itch at the ankle and find that Spanish needles have penetrated our sock, or a cocklebur has wedged into the top of our boot - and that our shoelaces, pants and jackets are plastered with beggar lice.
Why, as Oscar Wilde once asked, is nature so uncomfortable? Why does every autumn outdoor excursion have to include removing seeds from fabric?
Despite their annoying qualities, these 'natural attachments' make the outdoor world a much more interesting place. Try to keep that in mind the next time you are scraping beggar lice off your pants with a butter knife or a pocket comb.Plants have fascinating seed-dispersal methods. Most of them exploit wind, water and animals to spread and perpetuate their species. The success of these plants, in turn, contributes to the survival of many animal species that depend on them for food or shelter, and ultimately, to the integrity of ecosystems.
Jewelweed and witch-hazel, both common Missouri plants, have explosive seed capsules that discharge and propel seeds many feet. Hundreds of species in the composite or aster family, such as blazing stars and dandelions, have parachutes attached to their seeds that are carried aloft by wind. Fleshy fruit, such as permissions and wild plums, surrounds seeds and attracts birds and other animals, which then disperse them through their digestive systems. Plants like overcup oak have a corky layer inside the acorn that allows it to float down waterways to colonize new locations.
And then there are the annoying sticky seeds of, for example, plants in the genus Desmodium (known as beggar lice, sticktights, tick trefoil or tick clover) and the genus Bidens (called Spanish needles or beggar's ticks). These rely on furry animals to carry their seeds away from the parent plant to drop elsewhere and potentially germinate in other areas.
Such "seeds" (technically dry fruits encasing seeds) have ingeniously designed hairs, spines, barbs and Velcro-like hooks on their surfaces that cling to fur or clothing. The fruit's point of attachment to the parent plant is loose enough that it can easily attach to the coat or fur of any warm-blooded body that passes.