Where we are now is in one of the most common biomes in the Southwest: the piñon-juniper woodland. Its characteristic plants are the piñon pine and the juniper. As I looked up from my book just now, there they were right in front of me:
Although this isn't what most people think of as cactus country, it's pretty common to find little beavertail cactus (genus opuntia) hanging out with their bigger siblings:
The big old spines are the most obvious reason to avoid blundering into one of these guys. But the lasting misery if you do comes from the clusters of glochid hairs at the base of the spines. As Wikipedia observes:
Most cacti possess spines, some large enough to cause serious wounds. Glochids however, though smaller, commonly induce more troublesome, more persistent, dermatological manifestations in humans. Though minute, glochids commonly are barbed and once they have penetrated the skin barbed glochids are practically impossible to dislodge without leaving scraps of foreign material in the wound.
Most people who come in contact with glochids are pretty unhappy:
If the glochidia are allowed to remain in the skin, a dermatitis may ensue that will persist for months. It may help to treat the affected area with a topical corticosteroid.[ However, since the presence of glochidia is the inciting factor, removal of these minute spines would seem to be a more rational approach.
The thing is, they're really hard to remove. Go read the Wikipedia article referenced above!
Class dismissed. It's cocktail time for me!