Female Pronubas live in the blossoms. After mating, the moth collects a ball of yucca pollen and jams it onto the stigma (female part) of the flower. Yucca pollen is heavy and sticky; it doesn’t float around in the wind. Other insects do not transport it. The Pronuba insures that the plant will produce seeds by fertilizing the blossom and then she lays eggs in the base of the flower where the seeds will grow. The larvae that hatch from her eggs eat many seeds, but a lot of the seeds mature, too. The moth will not lay her eggs anywhere else.
The Pronuba must have yuccas to reproduce. The yuccas must have Pronubas to reproduce. Neither can get along without the other.
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A Prickly pear cactus [Opuntia]. Like all desert cactus, these are well adapted to the arid environment. Like Ephedra, cactus are all stem, have no leaves, and the stems (or “pads”) contain green chlorophyll, the critically important element in food production. Cactus spines are modified leaves that serve as effective protection, but are not functional food producers. When moisture is abundant, cactus pads get plump and smooth. During extended dry spells, the pads shrink and wrinkle as the plant uses the stored water. How has the weather been around here recently? Look at the cactus and you can tell!
8 0.5 (4.8)
You won’t get a very good view of Kachina Bridge here, but you will find it much easier to understand how bridges are formed if you walk out to the canyon rim. There is no trail, but it’s an easy walk without unusual hazards other than the ever present cliffs. Remember, DON’T WALK ON THE CRYPTOGAMIC CRUST!
Desert Varnish
[Desert] varnish, the dark streaks on the canyon walls, is common in arid areas such as this. Each time the rock gets wet, some moisture is absorbed by the rock. Water actually seeps into tiny spaces between the grains of sand. Later, the moisture is drawn out of the rock and evaporated by hot, dry air. While inside the sandstone, however, the water dissolves minute amounts of minerals like iron and manganese. When the water comes to the rock surface and evaporates, the minerals come with it—but the minerals do not evaporate. They accumulate on the surface of the rock over thousands of years, slowly forming a very thin dark crust.
White Canyon