Trail Tech

On the trails in the Sonoran Preserve in North Phoenix, topographic maps and backcountry sense have been replaced by cell phone technology. 

Botanical Weapons

I've got two flat tires on my mountain bike right now, thanks to Tribulus terrestris, one of the most well-armed members of the plant world. Also known as caltrops, the fruits have stiff, hard spines that are much like spiky weapons of the same name that has been used in war for over 2000 years to disable horses, elephants and barefoot soldiers. Larger versions have been used in modern warfare against wheeled vehicles.  These plants are equal to the metal version if you are traveling by bicycle, a fate I've befallen to over a dozen times in my life. Bummer!!

News to me, though, is the long-time medicinal use of the plant to "promote a healthy male libido and support testosterone."  I suppose this belief is derived from the Doctrine of Signatures that once guided herbalists, i.e. that whatever body part or desirable characteristic a plant emulates, it would also cure. So, if you're male and you want to be stiff and hard, like the spines of Tribulus terrestris, just drink a little tea of the plant. Unfortunately, clinical trials have not demonstrated any of the supposed benefits. 

Goatheads, devil's thorn and puncturevine are just a few of the other names used for this sturdy species. It thrives in desert climates and is also tolerant of extremely disturbed habitats, so is common in urban areas around the world. Although it has spread to every continent, it is believed to have evolved in the Mediterranean region.  Around here, you'll find it in parking lots, growing in cracks in the street, along highways, in empty lots and abandoned agricultural fields. A single plant can cover many square yards of land. Though the fruit is onerous, the little yellow flowers that precede them are very pretty.

Are Greens Green?

Using an average of about 150 acres per course, my calculations estimate that nearly two percent of the land area of the Phoenix metro region, or about 40 square miles, is devoted to golf. With 169 golf courses sprinkled around the Valley of the Sun, that's a lot of green space. But how "green" are greens?  Despite the volume of water necessary to maintain them, especially in the desert, the ecological value of golf courses is significant within the context of the urban area. Researchers J. Colding and C. Folke of the Stockholm Resilience Centre in Sweden compared the biodiversity and species richness of 200 golf courses around the world with that of adjacent land uses. Not surprisingly, golf courses supported more diverse flora and fauna than surrounding landscapes in urban and suburban areas. About 60% of courses are "roughs," which includes ponds, forests, sand pits and meadows, which greatly increases habitat diversity for wildlife when added to the fairways and greens. Better than an equally vast parking lot anyway!

Added to these benefits, tournaments like the Phoenix Open taking place in Scottsdale this week have found ways to incorporate environmental awareness into the game. Saturday is promoted as a "Green Out" to raise donations for environmental organizations. Tournament managers also boast that they were able to divert 97% of the waste generated during the week long event from going to landfills in 2012. This year they are aiming for zero waste. I'll be cheering them on!

Urban Native

Twining milkweed (Sarcostemma cynanchoides), aka fringed twinevine, is a native plant in the Sonoran Desert, commonly found growing on trees and shrubs along washes. Urban development has been a boon to this hearty vine, providing ample habitat in the form of wire fences.

Twining milkweed is one of the most abundant native plants found in industrial areas, bringing life and beauty to some of the most thoroughly altered parts of the desert. Best of all, the vine establishes readily on its own and requires no irrigation.

In the fall, beautiful clusters of flowers appear, which are excellent nectar sources for many insect species, and especially for the closely related queen and monarch butterflies.

The Pits

One of the conspicuous features of Phoenix landscapes is the acreage of blonde crushed rock that is spread in lieu of lawns. I've always wondered where all this gravel comes from, and found one source today at the Madison Granite gravel pit in north Phoenix. The site manager was proud to let me know that two truckloads of sand from this site had been purchased for filming of the Spiderman 3 movie. You can see the evil Sandman emerge from a pile of Madison granite at 37-40 seconds in this trailer. 

Although I was denied permission to photograph the quarry from the ground, Madison Granite is easy to spot on Mapquest, just east of I-17, and conveniently located near one of the City of Phoenix waste transfer stations. The future of the pit could go a couple of ways. It could function as a landfill, or like many other quarries around the nation, be transformed into a lake, such as this one below, which is just a few miles west of here in Peoria, AZ. I sort of like the idea that the rocks in my front yard are contributing to the formation of a future wetland, where migratory waterfowl can stopover or spend the winter. 

Saguaro Hive

Last spring I found and old saguaro that is host to a hive of feral honeybees (Apis mellifera), on a hill just a ten minute walk from my house.  I went to visit them a few days ago to see how the hive is doing after our record low freezing temps last week. I was glad to find them humming audibly in their sunny south-facing hole in the cactus.

On one of our coldest mornings, I had visited another nearby hive in the cliffs of Deem Hills. The bees there had hunkered deep into the crevice that day, but did send one bee out to investigate me. It buzzed at me but passed on by, having determined, perhaps, that I was not a real threat to the colony. A few days later, the bees there are also back to their normal activity, commuting into the neighborhood to gather nectar and pollen.

Chuparosa

Chuparosa (Justicia californica) is one of our native shrubs that has been adopted by the horticulture industry to be cultivated and planted throughout the urban area. Also known as hummingbird bush, the tubular flowers are stocked with nectar to lure their co-evolved pollinators. Look closely at the flowers and you'll see the pollen bearing anthers and pollen receiving stigma positioned perfectly so that the pollen will be dusted onto a hummingbird's head, and then dabbed onto the stigma of the next flower it visits.

Last week here in Phoenix, sub-freezing temps wilted the already blooming stems of chuparosa around our neighborhood. But any native plant that has made it through thousands of years of our erratic winter weather can bounce back from a freeze pretty quickly. Indeed, just one week after the last freezing morning, the local shrubs are back in business, which makes our hummers really happy!