Mutualisms in Cacti at 8,000' Elevation
It's always enjoyable to encounter plant relationships like this in ecosystems. Though I wouldn't necessarily call it a mutualism, it sure does come close.
Here is Mammillaria andersoniana - among a few other species - a very rare and tiny little species of cactus that grows out of rockwalls composed of the volcanic rock rhyolite. This species of Mammillaria doesn't often grown alone, but usually occurs with a Tillandsia species and a species of the "spike moss" (which isn't a moss at all), Selaginella.
Both the Tillandsia and the Selaginella no doubt provide a substrate for the cactus to germinate on this vertical face of rock, but the relationship likely becomes a mutualism once the Mammillaria reaches adequate size, with both partners benefitting & receiving an edge up in this dry environment.
I love noticing these kinds of associations. I've long noticed that plenty of Meso-American cacti species often grow in beds of lichens, mosses, & "spike moss" (the genus Selaginella) & this situation was starkly illustrated for me again recently.
I have no problem anthropomorphizing here, and I certainly think doing so can sometimes help us imagine how these mutualisms benefit all species involved, so long as we are able to think beyond our "bipedal primate frame-of-reference", accepting that there CAN be pragmatic scientific logic behind our depiction of these relationships. I think that lady Robin Wall Kimmerer talked about this in that book she wrote, the genera in question being Solidago & Symphyotrichum.
Whatever your take on it, it's an association that's sitting there right in front of you smacking you in the face when you're standing in habitat. It's also another example to me of why studying habitat - as opposed to just "collecting" plants in horticulture or focusing on plant and ignoring the rest - is so important. More importantly, CONSERVING & PROTECTING the habitat is important. These plant communities have a right to exist despite whether us human primates are able grasp the concept of whether leaving them intact and functioning benefits us or not (hint : it does).
