The Tillandsia Usneoides Plants

Characteristics

• Its common name notwithstanding, Spanish moss is not from Spain, and it's also not a moss. An unlikely bromeliad plant family relative is the pineapple (Ananas comosus). Pineapple is a terrestrial bromeliad that grows outdoors in U.S. Department of Agriculture plant hardiness zones 11 and 12 with its roots growing into the soil. But Spanish moss, which grows in USDA zones 8 through 11, is an epiphytic bromeliad -- also called an air plant -- because it grows attached to trees. Spanish moss has no roots, but it is a true flowering plant that is capable of performing photosynthesis to make its own food -- it isn't a parasite of its tree host.

Life Cycle

• Spanish moss flowers are not easy to see, but you may detect their presence by the fragrance they release at night. The tiny three-petaled flowers are green and may open successively on the plants for up to four months. Fertilized flowers produce seed pods that split open when mature and release hairy seeds that are dispersed by the wind. The seeds lodge in trees by using holdfasts that grasp branches or tree bark. When the seeds germinate, the new shoots can cling to branches with their scaly stems. Birds help propagate Spanish moss asexually by plucking strands to line their nests. The severed strands attach themselves to branches under the nests and grow into new plants.

Adaptations

• The cuplike scales, called trichomes, on Spanish moss stems allow the plants to cling to trees and also trap and hold water. During drought conditions, Spanish moss can go dormant and revive again when it rains, or when the humidity of the surrounding air rehydrates it. Typically, plant roots are the structures that absorb water and minerals for transportation throughout a plant’s vascular system. Because Spanish moss has no roots, its stems are adapted for this task.

Damage and Control

• Because Spanish moss is a benign epiphyte, which means it does not directly damage its tree host, any harm to the tree is indirectly caused by its prolific growth. Because trees generally grow faster than their Spanish moss guests, their limbs are usually able to withstand the weight of the hanging plants. Sometimes, the moss may grow so quickly it causes limbs to break under its weight. Extensive Spanish moss growth may also shade a tree’s leaves, impairing its ability to perform photosynthesis at the level needed to sustain healthy growth. You can remove Spanish moss from shorter trees using a rake or a hooked pole. For larger trees, you may need to hire a company with a bucket truck to remove the plants.