Picnic Table Naturalist, Page 3: Aliens

(above) My favorite alien: Verbascum Thapsus (Great Mullein)

Picnic Table Naturalist, June 8, 2009 – Aliens

A perennial North American political debate is border security, along with illegal aliens and all other economic and social issues loosely connected to it. The latest dispute was during the recent presidential debates, but it has since fizzled out, forgotten by everyone save a small constituency nearest to Canada and Mexico.

But, what about border security in the natural world? Ever since there’s been international travel and commerce (commencing seriously with colonial Philadelphia’s itinerant Bartram family) there has come with it the travel (accidental and intentional; beneficial and detrimental) of non-native plant species. In the last few decades, there have been realizations made and initiatives taken towards the identification of “invasive” species, but this term applies to a minority within the hoarier definition of “alien” species; several of which are cherished plants. Two prominent eastern-Pennsylvania examples of the former are purple loosestrife and Norway maple. However, there are many examples of the latter “alien” species. Visit and look carefully in any suburban forest or meadow plot, and you will quickly encounter numerous species which are officially alien (or non-native) to your area (Peterson’s A Field Guide to Wildflowers or other nature guide will help you make the distinction). Some quick examples (seen around my picnic table as I write) are garlic mustard, Norway maple, Vinca vine (aka periwinkle), and English ivy. Some meadow (and lawn!) examples are the marsh marigold, white clover, dog violets, great mullein, and crown vetch.

A sub-group of these “alien” plants are those introduced deliberately for specific purposes; even as international goodwill tokens, which eventually became warnings against naïve botany. Some examples here: kudzu (otherwise known as “the vine which ate the South”), promoted as forage and an ornamental by the Japanese government, and crown vetch, propagated by the Pennsylvania DOT as an effective erosion preventative along highways. Still other examples are multi-flora roses and Osage orange trees, both touted heavily to farmers during the last century as vigorous and effective (there’s that word again!) windrows. Neither is planted much as windrows anymore, and both, particularly the rose, have become nuisances which can choke out other native plants (often ill-equipped to deal with botanical aggression on their home turf).

Now, to entertain a botanical connection to a political issue: what about the illegal alien problem? There have been and continue to be many solutions posited, but one which is drastic enough to make a point in both society and botany, is the immediate initiation of the full removal of all alien peoples from the United States proper. To understand how nearly impossible and potentially deleterious this would be, apply it directly to botany. How possible would it be to completely eradicate all alien plants? Well, first there needs to be location of the offenders; then positive identification (easier said than done); eradication; and finally reparation for the inevitable wrongly-deported cases. Not very feasible, right? Simply something to think about when you’re tempted to castigate an “alien” group, and you come upon English ivy creeping through the native wintergreen in your local woods.

Alicia –   – (Friday, 12 June, 2009)  

Nicely put. I particularly like your last paragraph!

pam farrell  – (Saturday, 15 August, 2009)  

Nice mullen in the photo. We had one that grew over 6 feet.

pam farrell  – (Saturday, 15 August, 2009)  

Nice mullen in the photo. We had one that grew over 6 feet.

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