Introducing Convolvulus arvensis


While researching the spread and dispersion of noxious invasive species of fauna and flora, one of the issues I keep noting isn’t just how many really vile invasives were introduced deliberately, or even inadvertently. What stands out is how many invasives get out of control mostly because they’re just attractive enough to avoid utter extermination. I get a giggle over how heather spread throughout South Island of New Zealand thanks to the accidental importation of heather seeds as an unavoidable contaminant in sacks of oats, and how the early explosion of heather throughout the island was suggested as a deliberate attempt by Scottish immigrants to mark New Zealand as Scottish territory forever by introducing the national flower. (Speaking as someone of Scot ancestry, you should all be so lucky. After hearing tales from relations in Aotearoa about Riddell family history, if we’d wanted to claim South Island, everyone else would have known it when they woke up with their throats cut. Twice. And that’s just for uttering in public the filthiest four-letter words you could ever utter at a Riddell family gathering: “Last Call”.)

Bindweed 2

When looking at bindweed (Convolvulus arvensis), it’s not hard to see why the US Department of Agriculture lists it as a noxious plant in Texas. It grows in soils so poor that even bluebonnets have problems. It climbs up and buries just about any other plant in the vicinity. The tendrils are tough enough that I can see where Frank Herbert got the inspiration for shigawire. Trying to run through a field infested with bindweed is a good way to break an ankle, leg, or neck. (I will say that running through a field of bindweed is still better than running through a patch of saw greenbrier: I still have scars on my legs, right above my knees, from where I did that nearly a third of a century ago. I think trying to remove my lower legs with a bandsaw would have caused less damage and hurt considerably less.) I’ve jammed up Weedeaters by getting the head too close to a bindweed clump, having the line snag a tendril, and watching as the whole clump tried to murder the Weedeater in a display of self-sacrifice, and I even did that once with a riding lawnmower when I worked as a groundskeeper for Texas Instruments. Not only does bindweed laugh at most pesticides, but its seeds are so popular with small birds that no matter how many times you think you’ve wiped it out, it comes back the next season unless you fit every last sparrow, wren, and finch in the time zone with diapers.

Bindweed 3

Unfortunately, as with Japanese honeysuckle, you have a determined and virulent invasive with enough charisma that non-gardeners don’t immediately scream “Get me the flamethrower!” when they see it. I have occasional nightmares involving a little old lady somewhere who managed to fill her garden with every last invasive in the US, and everything’s absolutely fine until the day she leaves the gate open and everything escapes. In this nightmare, bindweed is the decorative bedding alongside the Brazilian pepper trees and beneath the Ailanthus.

Bindweed 4

On a purely scientific level, passing clumps of bindweed has its moments. About one flower out of one hundred has a tinge of pink to it, which is particularly noticeable on cloudy days. I also suspect that it has quite the ultraviolet signature, judging by the number of insects racing to the flowers in the early morning. Oh, and small harmless snakes such as garter snakes and ground snakes love to hide within the tangles as they chase prey. It’s not all that bad: I just don’t want it in my front yard.

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