Friday, August 30, 2013

Weekend Walkabout: Alert Gardener Spots Tillie Tree!

Alert Gardener Jim of Miami sent me some remarkable photos of a tree that is absolutely festooned with native Tillandsias. There are at least three separate species, probably more, living in great profusion on this tree in a suburban lot.
The trees around this tree (most of the same species) have hardly any Tillies at all. What is it about this tree that makes it so remarkably attractive to Tillandsias?
I've consulted my textbook on Tillandsias, Air Plants by David Benzing, and have not found a definitive answer. But there are some clues. Tillandsias can be very fussy about where they will grow. They like a certain sort of bark, and often, the presence of certain mosses or a particular species of ant. Does this tree harbor the right sort of ants? Does it grow the best moss? Or is it nearest to a sprinkler-sprayer so the Tillandsias get more water during droughts? What do you think??
When so many Tillandsias are involved, I have to ask that question of symbiosis vs. parasitism. At what point does the tree get hurt by its enthusiastic guests? According to my research, (completed with a couple of books, sunscreen, and a mimosa in my backyard), Tillies can cross the line into parasitism by weighing down and breaking tree branches, and blocking light that the host needs to photosynthesize. This tree seems healthy enough, but I'll bet it's worried....

We have no Tillie Trees here on the sand dune, but I do know of some gorgeous Gaillardia pulchella flowers that are perfect for weekend contemplation:
Have a wonderful weekend, and for those in the USA, Happy Labor Day!


  1. Very interesting Marla. How do the tillandsias get to the tree in the first place? Is it via seeds, or fruit, or are the small plants carried by some type of animal? Perhaps the reason this tree has so many is due to the way they travel from existing habitat to new habitat. Here in Maryland we have a lot of mistletoe in many of the trees. It is spread by birds moving the sticky fruit, usually on their feet. If the birds frequent a particular tree, that tree is more likely to end up with mistletoe on it. Ecology is a complicated business sometimes. :) Have a Great Labor Day.

  2. Tillandsias reproduce by offsets (pups) and by seeds. The pups may stick with the mother plant, or fall off of it at various stages and sizes, depending on the species. Seeds are very small and can be carried by birds, other animals, insects, or the wind. Growth of a new plant by seed is incredibly slow, though.