I originally identified these dried, mat-forming plants as trailing windmills (Allionia incarnata). Tom Chester corrected my misidentification. They are California caltrop (Kallstroemia californica), a member of the caltrop family (Zygophyllaceae), along with puncture vine (Tribulus terrestris), creosote bush (Larrea tridentata) and California fagonia (Fagonia laevis). In fact, Kallstroemia californica is not even on my Anza-Borrego plant list, and I don't recall ever encountering it in Coyote Creek. This plant would be hard to miss this year. It was apparently in bloom last fall. Special thanks to Tom Chester.

Regarding California Caltrop (Kallstroemia californica). According to Tom Chester (personal communication, 8 Mar 2023): "It was a "holy grail" plant for me for a decade, since i had never seen it. It turns out it is a strictly-monsoonal species, so there has to be monsoonal rain in the sandy areas where it grows. As you know, monsoonal rain is quite spotty, and not present in the borrego springs area very often."

This explains why I never noticed this fascinating plant and why it wasn't on my Anza-Borrego plant list. In fact, it was not listed in Flora of San Diego County by Mitchel Beauchamp (1986), the book I used for years in my Plant ID class (Botany 110) when I was once quite knowledgeable about our native flora.

California caltrop has small yellow flowers. Like puncture vine, the fruit separates into 5 seed-bearing sections; however, unlike punture vine, the sections do not have long, sharp spines like the medieval weapon called a caltrop. Images of the flowers and fruit of California caltrop are available at iNaturalist.

Naturalized hitchhiking plants often grow very well in disturbed sites, and this is how some of California's most noxious weeds were introduced. The earliest reported collection of puncture vine in California was made at Port Los Angeles in 1903, presumably the result of a ballast dump. Within a few decades it had spread throughout the state, reaching epidemic proportions in some cultivated valleys. The burs were carried in the wool of sheep, in hay, straw, other feed, manure, melons, alfalfa, cotton, potatoes, picking sacks and boxes, tents, sand, gravel, farm and industrial machinery, and in rubber tires of automobiles and airplanes. Puncture vine is the scourge of every bicyclist and is a major factor in the popularity of inner tube repair kits. Although it only has a "Sock Removal Difficulty Factor" (SRDF) of 3 in the official Wayne's Word Table Of Ultimate & Painful Hitchhikers, this may be a gross underrating for this naturalized hitchhiker.

Puncture vine belongs to the caltrop family (Zygophyllaceae), so named because of the shape of the wicked fruits. At maturity, the fruit dries and breaks apart into five seed-bearing sections called carpels. Each section is armed with several sharp spines that readily penetrate bicycle tires or your shoes. This plant family also includes creosote bush (Larrea tridentata) and California fagonia (Fagonia laevis), a lovely purple wildflower also found in Coyote Creek & rocky slopes of Coyote Mountain.

During medieval times, a vicious weapon called a caltrop was used in European warfare. This was an iron device with four points so designed that one was always facing upward, whichever way it landed, to impale the hooves of enemy cavalry horses. A similar device was also used in World War II to destroy truck tires on enemy supply convoys. The widespread water caltrop (Trapa natans) also has a four-pronged fruit that resembles a caltrop.

My serious passion for ants officially started after retiring from Palomar College. I was sitting at the summit of nearby Owens Peak wondering which tiny ant species was after the crumbs from my Nature Valley granola bar. It turned out to be the orange desert ant (Forelius pruinosus). Another ant on Owens Peak really sparked my interest because it was a species of Pheidole, the ant genus that fascinated me at age 10! If you are interested, this is all explained at the following link: Left: A curious (friendly) Pheidole vistana major worker on my thumb at the summit of Owens Peak. These warrior (soldiers) have fought with other larger field ants (Formica) on Owens Peak. From the remains of deceased ants in battlefield area, I am quite certain the Pheidole won.

The Ant That Triggered My Interest In Biology

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A Pheidole Colony in Coyote Creek

When I first saw this ant near a sand verbena in Coyote Creek, I thought it might be a new species for me. Pheidole yaqui was reported from nearby Palm Canyon Campground, Anza-Borrego Desert State Park. It seemed like a possible candidate; however, after reading the descriptions in the key to Pheidole species, I just can't be certain. This ant has a toothlike, subpostpetiolar projection that is lacking in P. yaqui (see following image). It belongs to the Pilifera Group, including P. bicarinata, P. barbata, P. xerophila, and P. yaqui. P. barbata is similar in overall appearance & coloration, but can be ruled out because it lacks propodeal spines on major and minor workers; however, some individuals of latest ant had indistinct propodeal spines. P. barbata occurs at Dos Palmas Oasis north of the Salton Sea. Although not distinct in my images, there may be psammophore on ventral surface of minor worker.

Antwiki Key to the Pheidole Pilifera Group

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Another Remarkable Ant Species in Coyote Creek

Have you ever tried to pick up dry, loose sand with fine-tipped forceps? This desert ant is adapted to soft, loose sand. Sand spilling out of mandibles is caught in the basket of long hairs on underside of its head.

More Images Of Pogonomyrmex In Borrego Valley

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Palm Canyon & Lake Henshaw On Morning Of Return Trip

All images on this page copyright © W.P. Armstrong