Arizona Summer "Poppies' - really Big-flowered Caltrop

This July (2021) was the rainiest in (measuring) history. A lot of the water came in heavy thunder showers and may have run off quickly, but we also had some long-lasting slower drizzle that hopefully soaked in deeply. I’m not sure that on the west side of the Tucson Mountains this will end the record breaking drought of 2020 and before. But temporarily, things are looking up: In the lower desert around our house, Palo Verde seeds germinate and seedling powerfully push up through the wet sand, Mammilarias bloom, Ironwoods and Mesquites leaf out, so do our Ocoltillos. Creosote bushes turn from brown husks into shiny-green yellow-star-spiked beauties.

At slightly higher elevations, grasslands turn into wildflower carpets. Silverdollar-sized (?) orange flowers of so-called Arizona Poppies are so far the main contributors.

Instead of Poppies, I’d rather call these wilfd flowers Arizona Caltrop or Kallostremia grandiflora, because this summer annual is not related to our orange poppies of spring that it superficially resembles. It rather belongs to the family Zygophyllaceae and is therefore a relative of the creosote Bush Larrea tridentata. Another relative that I sadly often encounter on our dirt road is the invasive goat-head or puncture vine (Tribulus terrestris).

A rich pollen load of the flowers is probably responsible for a common Spanish name: mal de ojos (sore eyes). They must also be rich in nectar, as big Scoliid Wasps, Colpa octomaculata are the main visitors, but these solitary wasps do not collect pollen. Nevertheless, curling their heavy bodies around anthers and stylus, they visit flower after flower, and seem to be major pollinators of Big-flowerCaltrp.

On the leaves of Kallostremia I repeatedly found a relatively uncommon leaf beetle, Leptinotarsa peninsularis. Although I yet have to find larvae, I think that Caltrop is the hostplant of this Leptinotarsa.