Where the Wild Things Are: Invasion of the 'Exotic'!

June 13 2009
Where The Wild Things Are … the 'Invasion' of the Exotic!

I often kid Sloane that I will enact revenge on my enemies the gardener's way: I will plant Giant Hog Weed (Heracleum mantegazzianum) in their midst and so shall they be destroyed by their own seduction! Sorry for the biblical tone but certain plants seem to set off that reaction for me. I have never seen Giant Hog Weed (both its common name and its scientific name are enough to send me into a rapturous swoon; I have come to belatedly realize that one of latterly seductions for me of the plant world -- besides what should be, but seldom is, its obvious charms -- is through naming – but let’s leave that to a later post) and I can’t now remember how I came across a reference to this ‘monster.’ One of the unfortunate things you will learn about me, is that I have a predilection for monomania, for plants which seem to have a blatant - even hostile! – disregard for the human world and which have a terrifying profligacy, one plant able to release up to fifty thousand seeds at seasons end. I guess you could call it the ‘Triffid Effect’ (based on the book by English author John Wyndham ) Maybe it was that industrial/punk band I played in during the eighties that helped release some of that chthonic plant energy, still squirming around in the underbelly of my psyche.

Here are some of the particulars of this particular eldritch squirmer:
Heracleum mantegazzianum is from Asia and was imported by the Victorians, those insatiable plant fanciers, as a bodacious architectural scale plant and that it is! It can grow 10 to 15 feet high in a season, can have a central, hollow stalk up to 2 inches in diameter and grows beautiful final umbrels of white flowers a foot or more in diameter (looks kind of like a monstrous Queen Anne’s Lace). But the final straw for many is that it is covered with small hairs which can cause photo-dermatitis on those who may touch it: upon contact and then going into the bright sun, burning sensations ensue which can lead to something like chemical burn scars for some and identical sensitivity to the uncovered skin for two years! Yeah, sounds like a bad mama jama …. (o.k. rest assured that I would not REALLY plant this, unless, you know….)…but damn it's abeautiful plant. If one were an art critic, no doubt there would be (and has been!) plenty of room for ruminations around ideas of beauty, exoticism, how categorization works, nationalism, regionalism, globalism and many other sorts of, uh, turf wars, a little bit of which I will address at the end of this post.

There are two web sites of varying degrees of hystericalness here and a video here which will give a flavor of the tensions around the plant. At this point it certainly has become a mythical Triffid for me, an aura only enhanced by these reports of dread.

But of course the most beloved/hated ‘invasive exotic’ for us southerners is the ubiquitous Kudzu (Pueraria montana var. lobata). I have to say that, among the favored few things that positively define the south for me (two others being the smell of Mimosas blooming in the summer along side the roadways) the ‘Kudzu monsters’ as they are affectionately called are also one of my favorites. They are called monsters because the vine imported from Japan creeps (at a high rate of speed one might add; the standard joke for Kudzu is that abandoned cars, concrete block, and 40 weight motor oil make the best fertilizer for Kudzu) over everything around it: phone poles, houses, bodies, cars, leaving large green bulbous masses, a veritable Telly Tubby landscape along large stretches of highway, smoothing everything into a pleasant, undifferentiated, undulating green mass, becoming maybe a teeny bit ominous as night fall approaches.

The hysteria is not nearly as pronounced as over my favorite-plant-to-hate the Giant Hog Weed, perhaps because it was first introduced in the late 1800s for erosion control, and like the Mimosa (Albrezia julibrizin) decided it liked it here in the south better than its homeland in Japan where apparently it is used for all sorts of things from tea to paper and more. None of those things for some reason has caught on in the US, although it sometimes is used for nitrogen fixing and silage but it is better known as an icon or logo or allegory. Here is a page which gives it more credit than common wisdaom would credit.

But I would dare say that for most southerners, who have mostly abandoned the family farm and moved to the city/’burbs that Kudzu is simply an emblem and an occasional nuisance, an unwanted reminder of a much larger kingdom that awaits outside the gates.

Wait a minute hold the presses! Another Kudzu analogy here! These conurbations/exurbs/whatever you want to call them, are like Kudzu in their out of control nature, and their making undifferentiated areas of blankness; in a way, its the story that a southern J.G. Ballard might have written: THE SMOTHERED WORLD.

Oops! Maybe it’s already been written
I’m now reminded of an old favorite of mine I read when I was much younger by bucolic sci fi author Clifford Simak, ALL FLESH IS GRASS. You gotta like it: aliens come to earth as plants and take over to create social harmony. I found a free on-line copy you can peruse if you like. Needless to say, Simak takes a quite different approach than Ballard.

O.k., maybe you get the drift of where I’m going with all this, there’s probably no need to go into the volumes of names which are now considered ‘invasives’ and ‘exotics’. If nothing else, I would like to problematize these characterizations for you. (And before you start writing your congressperson, let me say that even though I have some appreciation for the problems involved – the family farm in MS is now abandoned and largely engulfed with Kudzu – it sometimes behooves us to try to think outside the box, er, yard).

I’m sorry, but I’m an inverterate lover of exotic plants. One gardening wag once wrote that ‘you’ve never really tried to grow a plant until you’ve killed it three times’, a sentiment I can attest to…but that’s another post also. I do love native plants (just went recently to the Native Plant Garden out on Panthersville Road recently and its a great place) but I am suspicious of the appellation ‘native plant’: native since what period of time? The time of the Mississipi Valley mound building Indians? Before or after the Little Ice Age? Before or after European colonization? Before or after Middle America Indians began trade relations with North American Indians? It seems to me that we can barely, if at all, know many of these things. Rather, indeed, there seems to be an (excuse this word in a gardening blog) ideological inclination in the categorizations which are used, an apparatus which has become adapted to an homegenized world. It’s always some thing which has been interesting to me, the threat level certain plants seem to bring forward and sometimes even apparent misinformation. (The Malaleuca forests of Florida are another extreme example of an ‘invading species’.)

Perhaps some may think that I am approaching this whole native/exotic thing from too much thinking … or maybe I’m bringing some form even of exotic thought to the ‘problem’ … maybe so, after all, it’s kinda what I do….but whatever happened to 'biodiversity'? Evolution?

But even inasmuch as that might be the case (i.e., I’m off my punk rocker brain) I was heartened to find, while I was doing a seed search, a seed bank proprietor who also has a different take on a the matter. A quote then I’m outa here for a couple days folks.
(btw: check out the J.L. Hudson seed site … incredible).

Well, this is a little longer quote than I meant to take down, but the whole page is very interesting and controversial I would suppose.

NATIVES Vs. EXOTICS: THE MYTH OF THE MENACE

Non-Native Species as Allies of Diversity

There is an idea, popular in some circles, that 'non-native' species are somehow harmful, that 'aggressive exotics' can invade ecosystems and destroy 'native species'. It surprises me to see the public and biologists alike uncritically accept this absurd notion.

"But the Emperor has no clothes!"—Folktale.

In this spirit I would like to point out that there is absolutely no biological validity to the concepts of 'native' and 'exotic' species, nor is there evidence that man's introduction of species into new habitats has any negative impact on global biological diversity. On the contrary, the aid we have given species in their movement around the world has served to increase both global and local diversity. It is one of the few human activities which is beneficial to the non-human creation. It cannot be distinguished from the movement of species by wind or ocean currents, or the aid other species give to their fellows, such as the distribution of seeds by migrating birds.
"All living beings have the right to engage in the struggle for existence."—L. H. Bailey.

There are no adequate definitions of 'native' and 'exotic', since there has been constant movement of species since the beginning of life. Witness the migration of species across the Bering Straits and the Isthmus of Panama. Great exchange of species has occurred between both oceanic and continental biota in these areas as they have been repeatedly submerged and exposed, alternately being corridors for aquatic and terrestrial life. In response to the Ice Ages, great movement of species has occurred. Even now, I understand that the armadillo is extending his range north from his native México. Is he an exotic invader? If we naturalize elephants in the tropical Americas, will they be exotics, or will this simply be the return of the Proboscidea to their pre-glacial range?

Apparent cases of destructive invasion by 'exotics' are usually examples of the beginning of an outbreak-crash population sequence occurring as a species moves into the niche provided by a heavily man-disturbed habitat, to be followed by the inevitable crash and subsequent adaptation and integration of the 'exotic' into the local ecosystem.

Intact ecosystems are highly resistant to invasion, and there are also many cases of 'exotics' acting as nurse-plants and revegetators, helping the native ecosystem to reclaim its man-destroyed habitat. I have seen a grassy meadow and a field of star thistles side by side, with only barbed wire separating them. The fence can't stop the thistle seed, yet it does not invade the intact meadow, showing the thistle to be an antibody-like response of the prairie ecosystem to overgrazing by cattle.

New species create niches for more species, further increasing potential diversity. Many species are extinct in their original habitat, existing only where they have been introduced to new areas by man. We are changing the world through our destruction, pollution, and now possible climate change. Local ecosystems need the infusion of new species to help their adaptation to a changed environment.

"You stay, I go."—Ishi, last of the Yana.

It is ironic to me to hear people of European ancestry accuse other organisms of being 'invasive exotics, displacing native species'.

Even the wildest unfounded claims of invasion by 'exotics' pale in comparison to the land area occupied by technological man's monoculture crops. These crop-deserts and modern man's extractive land-domination economy are the threat to biodiversity, not 'escaped exotics'.