Flora Fact: Out on a Limb
Ball moss lives in trees but doesn’t harm them.
By Eva Frederick
Examine the twisting branches of live oaks (and a host of other trees) around Texas, and you’ll see one of the state’s most maligned plants: spiky-looking, dull-green ball moss.
Due to its habit of heavily colonizing tree limbs, ball moss is often assumed to have the same parasitic qualities as mistletoe, which burrows its modified roots into the branches of trees to suck out their nutrients. But these little gray-green pom-pom plants don’t even have roots: they get everything they need from the air.
Ball moss is often seen in great numbers on dead branches, which might lead observers to believe that the plant is to blame. But often these branches are dead because they lie beneath the tree’s canopy, where there is not enough sunlight for them to live. Ball moss, on the other hand, thrives in low-sun, high- humidity areas, so these dead branches are a perfect habitat.
Like its cousin Spanish moss, ball moss is not actually a moss at all, but a flowering plant in the same family as pineapples. The round ball moss rosettes, which are made up of two to 60 individual plants, flower in an understated explosion of long, slender stems topped with tiny, one-petaled lavender flowers.
When the flowers are fertilized (scientists think they are often self-pollinated) they produce brown seed pods stuffed with fluffy seeds. These are carried by the wind to land on other tree branches where they can take root and start their own colony.
Under a microscope, the smooth spikes of ball moss turn out to be completely covered in papery scales, which allow ball moss to harvest water from vapor in the air and take in other nutrients from floating dust. Because of these, ball moss can even act as a biofilter, taking pollutants out of the air. Ball moss also provides a cozy home for several types of insects and mites, and fixes nitrogen in the air, which is then transferred to the soil when the ball moss eventually falls to the ground.
The next time you see a clump of ball moss, give it a little love; even this small, understated plant has its own special place in the ecosystem.
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