So Wet That Things Are Dry

Dump a garbage can full of water on a dry load of top soil.  You will find that it runs off in all directions and some of it turns into sand; the organic components of the soil having washed away and the bare mineral contents of what consists of ground becomes exposed and featured as the star of the show.  So it is even in the rainiest parts of the world, and indeed our wonderful continent.  The banks of the Amazon are routinely inundated and then exposed and often leave lovely beaches in the wake of the emptying river.  The edge of the rainforest becomes a desert of sorts.  So too does the edge of the sea, with wave action constantly moving around large quantities of the prime material component of our lovely beaches. 

In general, North America starts out very wet on the west coast, with quite dry patches south of Monterrey Bay in California, and then turns bone dry past the mountains which trap the Pacific moisture dead in its tracks.  Eventually deserts, more mountains, grasslands which are nearly deserts, and then the edge of a grand forest progresses eastward and southward.  The Gulf of Mexico sends its bounty west and north into rainier lands of less extreme temperatures and we have our grand forests both tropical and temperate.  Still, this is a pretty dry place.  Even in the humid Gulf Coast one can have many cloudless days and rather arid conditions here and there, especially on beaches and riverbanks.  So it is that we can have cacti even in Florida and New York, far from where we envision they properly belong.  One only imagines what the first settlers thought of such plants, but we know for sure that wherever their descendents found them, they considered them to be a nuisance to draft animals and weeding hands alike and many were removed. 

The best places to find them in the moist east these days would thus be their most practical locations, those dry and sunny places where other plants tend to give up the ghost, the dunes of beaches.

Here we have some Eastern Prickly Pear (Opuntia Humifusa/Compressa), found on the sandier reaches of Hunting Island in South Carolina.  Too dry for the coastal marsh species, too exposed for other island denizens, too much beach and not enough ocean.  Beside them lie cones of the local Slash Pines (Pinus Elliotii), destined to be food for some sort of creature or another, unable to seed properly in a place more suitable for the desert junks that either gets ignored or detested.  The naturalist on staff at the state park noted that no one usually notices them, much less asks about them, despite how exotic and unique they seem to be this far east.  Nevertheless, our dry land has cacti nearly north to the arctic treeline, and yes, right next to both oceans.