(Common buckthorn, now considered as an
invasive species in parts of North America)
The spines like roofing nails, the branching dense—
on the Plains, a plant like that had plenty of takers.
Laid out in hedgerows, windbreaks, pasture fence,
it crowned with thorns the outlines of the acres
of pioneers who set their minds, and feet,
flat on the ground, to turn it to their will.
But history, never simple or complete,
met botany, in which buckthorns don’t keep still:
They rove, seize opportunities, play their cards
sharply, and cheat at plant-genetics races.
Scourges of wildlands and of well-kept yards,
they screw us to all sorts of sticking places
and join with other European invasions,
pricking like conscience down the generations.