During a dry spell, if a cold front triggers an inch or more of rain on lawns or other open ground, Drummond's rain lilies will appear in two to three warm days, or a week in cool weather. Miraculously, out of nowhere it seems, they are blooming. The single snow white flowers on leafless stems up to a foot tall are a botanical resurrection that may occur after any extended dryness from June to October. Often they form eye-catching colonies, so it amazes me that yard mowers just cut right through them as if they don't exist. Rain lilies are "weeds" in suburban lawns but to me a pleasing reminder that natives can survive our monocultural mania.

Copper lilies have the same flowering regime but occur locally only along highways. A botanist colleague thinks this species could be an historic import brought by Spanish explorers-missionaries from temperate South America via Mexico. Its local distribution seems to follow the old Spanish trails, except where soil has been moved around by construction. Copper lilies bloom in what corresponds to early spring in the temperate southern hemisphere, and there are no reports of the plant in the six thousand miles of intervening space. If they were responsible, the Spanish of five hundred years ago were only human, insofar as introductions are concerned.

People have a tradition of importing aliens. Even first Americans carried and traded animals, plants, and seeds. Considering that to move domestic and unintended organisms among continents and islands is human, our capacity to alter faraway landscapes is both fascinating and disturbing. I point to modern society for self-service that threatens the Biosphere but acknowledge that we have learned from successive generations of ancestors whose introductions, intended more for personal survival than for pleasure, became agents of extinction by outcompeting, overeating, or poisoning native organisms.