Garden sign story: Air Plants
They’re so hairy! Bromeliad leaves have trichomes — microscopic modified hairs or scales.
Tillandsias have velvety surfaces that reflect light and heat, giving them silvery sheen. Spanish Moss, (Tillandsia usneoides) doesn’t have roots; instead, the trichomes on its surface trap and absorb moisture from rainwater and fog, and nutrients from the air. Some tillandsias have protective trichomes that ooze mucilage — sticky goo that deters small herbivores and pathogens.
Image (left): Scanning Electron Microscope image of a bromeliad trichome. ©Science Photo Library/Alamy Image (right): Spanish moss in Caddo Lake State Park, USA.
Desert-dwelling tillandsias can handle searing heat and sunlight. Their hairy trichomes trap humidity, keeping their leaves moist. The trichomes also act as sun-screen, reflecting damaging infrared and UV radiation.