Tumblin’ tumbleweed

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The spring winds blew the other afternoon, hurling great clouds of soil from newly-plowed fields into the air. Tumbleweeds bounced across roads and open spaces like giant soccer balls. When my step-daughter, Molly, and I rode our bikes across town the next morning, drifts of prickly tumbleweed skeletons turned the sidewalks into a slalom course.

A symbol of the West in movies and popular songs, tumbleweed is actually not native here at all. As Russian-thistle, its other common name, suggests, tumbleweed comes from Russia’s arid shrub steppes, half a world away. After hitching a ride to America in the 1870s with flax seed brought by Ukrainian farmers, tumbleweed spread like wildfire across disturbed places in the West, colonizing plowed prairies, overgrazed rangelands, road edges, corrals, and the bare earth of abandoned farms. No wonder that one Hopi name for tumbleweed is “white man’s plant.” By the time the Sons of the Pioneers recorded “Tumbling Tumbleweeds” in 1934, this invader had come to symbolize the rootless, restless Western culture.

Tumbleweed is now ubiquitous throughout the West. When young, bright green, and succulent, tumbleweed, a relative of spinach, attracts browsers and grazers. Desert cottontails and small rodents nibble on its high-calorie shoots, as do pronghorn antelope, bighorn sheep, domestic sheep, and cattle. But this fast-growing annual quickly becomes inedible, forming a globular mass of tough and prickly stems, as it grows up to six feet high, and fifteen feet across.

One way that botanists classify plants is to label them by the conditions they prefer: for instance, plants adapted to saline soils are “salt-lovers”; others requiring the damp soils along streams are “water-lovers.” Tumbleweed is a “wind-lover.” Tumbleweed’s minute flowers, containing no nectar to attract bees, wasps, hummingbirds, or other nectar-sipping pollinators, depend on the wind, releasing clouds of tiny pollen grains to float on the river of air. Because of its windborne pollen and its abundance, tumbleweed is a major irritant to hay fever sufferers in the Southwest.

Wind assists tumbleweed again when the seeds are ready to disseminate. Tumbleweed’s large, dry, ball-shaped skeleton sways with the tug of the wind, until eventually the single stem snaps, freeing the plant to bound across the arid soil. With each bounce, tumbleweed drops some of its prodigious number of seeds – a single plant can produce up to 200,000 seeds – spreading its genes far and wide before piling up in the lee of a building or snagging on a fence.

Like them or not, tumbleweeds are a part of the modern West, a reminder of our heedless tinkering with the balance of arid environments. As spring winds propel tumbleweeds into the air to leap across the landscape and scatter their progeny, I dream of the day when their seeds will have a hard time sprouting in healthy deserts and grasslands.