Saturday, May 15, 2010

Ocotillo


Bina tapped the scarlet buds growing from the gray spiny stalk. She stripped the seeds, crushed them against a rock, and then added nopal cactus generating a gooey supper gruel. As the evening sun set she laid against the slope of the arroyo and watched the shadows in the thin forest of spiny stalks disappear with the night.

The Ocotillo plant also known as the Devil’s Walking Stick, Jacob’s Staff, desert coral, candlewood and coach whip is native to the Trans Pecos and the desert southwest including Baja California. The scarlet blossoms that grow from the slender spiny branches have been used by natives for food and beverage. The Cahuilla soaked the blossom in water for drink and the seeds, crushed into flour, have been eaten as cakes and mush. Hardened nectar from the blossoms was consumed as rock candy.

The plant’s spiny branches have been found in pre-historic wattle and daub structures in the La Junta region of the Rio Grande providing structural support for the earth plaster. The Seri tribe also used the Ocotillo for their brush houses. The branches are still used today to fashion fences that can become living hedges when posted in the earth with sufficient rain.

Heights of thirty feet have been recorded with widths approaching 10 feet. The Ocotillo blossoms produce nectar with the flavor of honey and are favorites for hummingbirds.

To survive in the hot harsh environment of the desert southwest the Ocotillo sheds its leaves during low water periods thereby reducing the energy and water requirement to survive. Most of the year the long stems of the plant are bare showing only a dead waxy gray with rigid spines but it can generate enough photosynthesis to produce new leave buds within five days after receiving water. In five weeks these leaves turn yellow and drop. These quick life cycles may occur 4 to 5 times a year and produce sufficient sugars needed for growth.

Monday, May 10, 2010

Bluebonnets


“Nothing quite like a field of Blue Bonnets against the white hide of a Brahma,” a Texas Representative was said to say during the 1901 debates of what bloom should be the state’s flower.

Representative Phillip Clements of Goldthwaite suggested instead the cotton boll, calling it the “white rose of commerce.”

Rep John Nance Garner of Uvalde begged to differ suggesting the prickly pear cactus bloom was far more beautiful and the plant itself symbolic of the rugged state. Although Cactus Jack went on to be Vice-President of the United States he lost this debate.

The Texas Bluebonnet actually comes in five species of the genus Lupinus. The Big Bend Bluebonnet, Lupinus Havardi which bloom in spring throughout the Trans Pecos, have violet flowers with a yellow stamen.

The Lupinus Subcarnosus also known as buffalo clover, was the official species selected by the House of Representatives in 1901 for the state’s flower. These smaller flowers are deep blue, but occasional random genetic mutation color them white. The flowers have a central greenish-yellow center that, with age, turns red. This species grows in the southern and eastern parts of Texas near the Gulf of Mexico.

In 1971 all five lupus varieties in Texas were deemed official.

Lupinus, which is a Latin word meaning wolf, was perhaps chosen by Swedish taxonomer Carolus Linnaeus, because bluebonnets or lupins were thought to devour the soil. In fact they enrich it.

Bluebonnets are part of the legume family which includes mesquite, clover, alfalfa, beans, and peanuts. All legumes are nitrogen fixers, meaning these plants are able to take nitrogen out of the atmosphere and convert it to a nitrogen form usable by the plant. Through a symbiotic relationship between the plants roots and microorganisms known as rhizobia, atmospheric nitrogen is converted to ammonia compounds that help the plant grow and compete with other plants. In return, in a form of classic mutualism, the plant supplies the bacteria with carbohydrates, proteins, and sufficient oxygen so as not to interfere with the fixation process. This is known as diaztrophy and occurs inside nodules growing on the roots.

Lady Bird Johnson convinced the state of Texas to seed wildflowers including bluebonnets across the state’s highways. It is legal to pick the state flower, but watch how you park.

Saturday, May 8, 2010

Monahans Sand Dune Field


Bina laid in the shadow of the dune feeling the sand sift down her shoulders collecting in the damp of her stomach and forming yet another dune. The wind above blew more sand down the ridge creating tiny furled rows that avalanched in a steamy wave like sea foam coming off a breaker. She pushed her hand through the taupe, brown and red grains and marveled at their uniform size.

The dune field north of Ft Stockton, known as the Monahan’s Sand Dune field is a recent geologic phenomenon. Formed in the last 12,000 years as the Trans-Pecos became more arid, the windblown sands pile up against the western edge of the Llano Estacado and fan out west across the Pecos plains in a 60 x 20 mile swath to New Mexico.

Sparse vegetation and wind couple to shape these mobile sands into dunes. Constantly changing in shape, these elongated mounds are the result of the Aeolian process. Aeolia is the Greek god of wind. In science the Aeolian process is about how the wind shapes the surface of the earth through erosion, transportation and deposition of unconsolidated sediments in an area.

Wind erodes the surface by lifting up fine grained particles. Known as deflation these particles are transported often to nearby places but occasionally these particles reach the stratosphere and are sent far away. The turbulent eddy action of the wind also acts to change the shape of the surface sand. Abrasion is a third component of the Aeolian process whereby particles rub against each other changing their individual shapes.

Dunes are generally longer on the windward side. On the lee side the angle of repose is steeper making for a shorter slip face. The trough between dunes is called a slack.

Many specialized animals have evolved to adapt to the ever changing topography of a dune field. Most dunes form in arid and semi arid regions of the world but often water can be found several feet below the sand in the slacks of the dune.