Sunday, May 22, 2011

Woolly Plantain

What’s blooming in the area: Snowball, Persian yellow, pink shrub, hybrid tea and miniature roses, pyracantha flowers above last year’s dark berries, wisteria, silver lace vine, iris, peony, oriental poppy, Jupiter’s beard, purple salvia; grapes killed by cold and those that hadn’t broken dormancy both leafing; buds on daylilies.

Beyond the walls and fences: Tamarix, fernleaf globemallow, cheese mallow, western stickseed, purple and tumble mustards, alfilerillo, scarlet bee blossom, white evening primrose, bindweed, gypsum phacelia, woolly plantain, escaped alfalfa, American licorice, western goat’s beard, native and common dandelions, June, needle, rice, and three awn grasses; cheat grass turning red; buds of Russian olive and loco; Virginia creeper seedlings and tree of heaven suckers coming up.

In my yard: Beauty bush, privet, skunkbush, winecup, vinca, yellow alyssum peaked, golden spur columbine, oxalis, baptisia, small-leaved saponaria, Bath pinks, snow-in-summer, blue flax, pink evening primrose, pink salvia, catmint, perky Sue and chocolate flower; buds on hollyhock, sea pink and coral bell; seed pods appearing on Siberian pea tree; rose of Sharon developing new leaf buds after existing ones killed by cold; put in tomatoes and warm weather seeds.

Bedding plants: Sweet alyssum, pansy; buds on snapdragon.

Inside: Zonal geranium, aptenia, asparagus fern.

Animal sightings: Cows brought into village pasture; hummingbird around Bath pinks, gecko, white spider crawled out of iris flower, hornet tried to land on snowball in the wind; harvester and small black ants, earth worm.

Weather: Some rain late Tuesday, followed by near freezing temperatures Thursday morning that punished some plants and flowers; winds most afternoons; 15:17 hours of daylight today.

Weekly update: The most amazing thing about woolly plantain is where it grows. While it’s interesting the little annual has bloomed at least three years along the road, it’s astounding the only place it grows outside the arid west is Patagonia in southern Argentina and Chile.

Nina Rønsted’s team believes Plantago diverged within the Plantagina family a little over seven million years ago in the Miocene when grasslands developed and that the genus began spreading about 5.47 million years ago. Most of the subgenera existed before the formation of the great glaciers two million years ago.

Some species of Plantago emerged in the historic record in Patagonia some 17,000 years ago when the glaciers were receding. Vera Markgraf’s team found pollen in cores that suggest the area around Coyhaique in the Aisén province of Chile was drying into an open ground shrub-steppe. The genus increased between 13,700 and 11,000 years ago when grasses dominated the steppe and fire activity declined. The pollen then disappeared from their soil samples when the amount of charcoal increased.

Farther south Rodrigo Villa-Martínez and Patricio Moreno found Plantago pollen in soil cores from 12,600 years ago drilled in the Torres del Paine National Park. It was disappearing from the strata by 10,800 years ago when the westerly winds began moving and moisture levels began changing.

Today the South America range of woolly plantain extends from Patagonia into the pampas north of Buenos Aires, but stops at the Amazon drainage. In Chile, it doesn’t reach as far west as the coast.

One would guess Plantago patagonica began as a grassland species that survived in refuges during the glaciers to reemerge when conditions dried. The grasslands would never have had to be contiguous for it to spread between the tip of South America and New Mexico, just close enough for migrating animals to spread the reddish-tan seeds.

Today, the short plant is primarily found on the western plains and in the intermountane region from Baja and Sonora north into the prairie provinces of Canada with scattered populations through the upper midwestern areas freed late from the ice. In Ohio, the only known population grows on “an old beach ridge associated with pre-glacial Lake Warren” in Williams County, which borders Michigan. In Michigan, the taprooted annual’s been found in the band of counties north of the glacial hills separating the state from Ohio and near Lake Michigan.

Rønsted’s group implies the fires that came with a changing climate and forest vegetation is what reduced its range. A team led by Todd Esque found that recent burning caused a significant decline in the number of Plantago species seeds in the ground in the Mojave, and the loss was greater for plants that grew under shrubs than in the open. While a single fire wasn’t enough to exterminate the plants, the repeated fires east of the Mississippi could certainly have had that effect, if they had once grown there.

In the areas that remained grasslands, grazing may have limited woolly plantain’s population. It’s eaten by guanaco and sheep in South America, and cattle and prairie dogs in this country. All those mammals prefer grasses, but the winter annual is eaten because it’s there when other vegetation’s scarce and it’s neither poisonous nor prickly.

If the plants are able to survive long enough to reproduce, the seeds are collected by harvester ants. However, if the seeds survive, they can last some time in dry soil to germinate when conditions are right.

In my yard, the narrow spikes appear for a few years, then disappear. They bloomed in my north-facing garden from the middle 1990's until about 2001. In 1999 they emerged along the east side of the house where they grew until grasses took over in 2004. By then, some seeds had settled in back where they were last seen in 2008. They can survive competition in the desert, but perhaps not in wetter areas where plants become more muscular.

If patagonica is a species that once had a much larger range and has been forced to retreat to disconnected environments hostile to other plants, it has persisted because it modified itself into a winter annual rather than a perennial. Unlike the common plantain I knew as a child, which had broad leaves that lay on the ground, this has narrow leaves that stand erect to collect the sun without being overly exposed.

Most important, the plant has developed an ability for a single seed to germinate and reestablish a colony. The tiny, four-petaled flowers appear in dense, short stalks covered with white hairs that isolate each flower. They fertilize themselves by activating the male anthers when the female stigmas are receptive. Most plantains are out-breeders.

Edward Voss thought woolly plantain probably wasn’t native to Michigan because the earliest report was from Washtenaw County in 1928. Judging from the plants in my yard and growing down the road, it seems to be a native plant that’s constantly being reintroduced back into its historic range, perhaps by vehicle and heavy equipment tires since the 1920's. Then, it dies out for the same old reasons, because nothing really important changed in its absence.

Esque, Todd C., James A. Young and C. Richard Tracy. “Short-term Effects of Experimental Fires on a Mojave Desert Seed Bank,” Journal of Arid Environments 74:1302-1308:2010.

Kartesz, John T. Floristic Synthesis of North America range map, available on John Hilty’s Illinois Wildflowers website for “Plantago patagonica (Woolly Plantain).”

Markgraf, Vera, Cathy Whitlock and Simon Haberle. “Vegetation and Fire History During the Last 18,000 cal yr B.P. in Southern Patagonia: Mallín Pollux, Coyhaique, Province Aisén (45°41'30¢ S, 71°50'30¢ W, 640 m Elevation),” Palaeogeography, Palaeoclimatology, Palaeoecology 254:492-507:2007.

Ohio Department of Natural Resources. Division of Natural Areas and Preserves. “Plantago patagonica Jacq., Woolly Plantain,” available on-line.

Rønsted, Nina, Mark W. Chase, Dirk C. Albach and Maria Angelica Bello. “Phylogenetic Relationships within Plantago (Plantaginaceae): Evidence from Nuclear Ribosomal ITS and Plastid trnL-F Sequence Data,” Linnean Society Botanical Journal 139:323-338:2002.

Sharma, Namrata, Pushpa Koul and Awtar Krishan Koul. “Pollination Biology of Some Species of Genus Plantago L.,” Linnean Society Botanical Journal 111:129-138:1993.

Villa-Martínez , Rodrigo and Patricio I. Moreno. “Pollen Evidence for Variations in the Southern Margin of the Westerly Winds in SW Patagonia over the Last 12,600 Years,” Quaternary Research 68:400-409:2007.

Voss, Edward G. Michigan Flora, volume 3, 1996.

Photograph: Woolly plantain growing along the shoulder, its spike shrouded in white hairs, 15 May 2011.

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