Euphorbia micromera (desert spurge) ( ) Euphorbiaceae Our C₄ herbaceous desert flora contains 16 native species of spurge ( Euphorbia ). These prostrate or low growing annuals and herbaceous perennials that flower almost any month of the year. Most have broad ranges, extending well outside of our desert region with several non-native species also widely naturalized. One of the distinctive features of the spurges is the milky sap contained in their stems. What appears to be a single flower in spurges is instead a cup-like structure called a  cyathium  that holds a central female flower surrounded by several male flowers. The structures that look like petals are extensions of the cyathium. Desert spurge is a common prostrate annual. "California Desert Plants, Philip W Rundel, Robert J Gustafson, Michael E Kauffmann."

  Euphorbia albomarginata (rattlesnake weed) ( ) Euphorbiaceae Our C₄ herbaceous desert flora contains 16 native species of spurge ( Euphorbia ). These prostrate or low growing annuals and herbaceous perennials that flower almost any month of the year. Most have broad ranges, extending well outside of our desert region with several non-native species also widely naturalized. One of the distinctive features of the spurges is the milky sap contained in their stems. What appears to be a single flower in spurges is instead a cup-like structure called a cyathium that holds a central female flower surrounded by several male flowers. The structures that look like petals are extensions of the cyathium. Rattlesnake weed is a widespread, prostrate perennial whose common name arises from its use to treat rattlesnake bites. "California Desert Plants, Philip W Rundel, Robert J Gustafson, Michael E Kauffmann."

  Proboscidea althaeifolia (devil's claw, unicorn plant) ( ) Martyniaceae Among our showiest desert annuals, but relatively uncommon is devil's claw. This unusual member of the unicorn-plant family also utilizes C₄ metabolism and thus summer flowering. Devil's claw is a brilliant, yellow-flowered perennial. It has a sprawling growth form with large, moist, and sticky-lobed leaves. The large bilaterally symmetrical flowers, up to 1½ inch across, look like those of jacaranda and other flowers in the related bignon family ( Bignoniaceae ). It is a perennial with a stout tap root that prefers dunes. The origin of the rather sinister name devil's claw is because of the long, woody capsules, up to 3-4 inches in length, which split open at one end to form a pair of curved claws. These claws readily cling to the hooves of grazing animals, or your shoes if you are not watching where you step. Since these claws don't fit the hooves of native grazing animals, scientists have s...

  Cylindropuntia fulgida ( ) ( ) Cactaceae Hikers swear that the plants reach out and grab boots and pant legs. But in fact the spines are so strong that even the slightest grip is enough to cause one segment of the plant to break away. Don't try pulling it out; it will only stick to your hand. Experienced travelers carry a comb and use it to brush the plant away in one swift, painful motion. "Wicked Plants, Amy Stewart."

  Cylindropuntia bigelovii ( ) ( ) Cactaceae Hikers swear that the plants reach out and grab boots and pant legs. But in fact the spines are so strong that even the slightest grip is enough to cause one segment of the plant to break away. Don't try pulling it out; it will only stick to your hand. Experienced travelers carry a comb and use it to brush the plant away in one swift, painful motion. "Wicked Plants, Amy Stewart."

Quercus lobata (valley oak) ( ) Fagaceae Many oak trees host species of wasps, but California's valley oak is one of the best-known and most hospitable of all the oaks. The process begins when a wasp lays an egg on an oak leaf. The plant cells start multiplying at an unusually high rate, forming a kind of protective cocoon called a gall. Eventually the egg hatches into a larva, and the gall, which can get to the size of a baseball, becomes a home to the larva and also gives in something to eat. The larvae emerge as full-grown wasps. One species of wasp causes the valley oak to form small galls that drop off the tree. The galls can jump around for a few days as the wasp inside tries to break free. earning them the name "jumping oak galls". "Wicked Plants, Amy Stewart."