Brush up against a yucca plant and you won’t forget it.
The needle-like points on its long, narrow leaves can deliver memorable puncture wounds.
Yuccas are relatives of aloes, hostas, asparagus, and lilies.
More than forty species of yucca occur throughout the Americas and the Caribbean, mostly in hot, arid regions.
Several kinds are native to South Carolina, including Spanish bayonet (Y. aloifolia), which can reach impressive heights of 10 feet or more.
In the Lowcountry, look for yuccas growing above the sand dunes and in other exposed, sandy spots near the ocean. They’re easily recognized by their rosette of dagger-like leaves and tall stalk of beautiful, creamy-white flowers.
Yuccas are also popular landscape plants since they’re highly tolerant of sun, heat, salt, and drought.
The leaves contain long, tough fibers, once woven by native Americans into baskets and rope. The roots were used for making soap, and the flowers for food.
Yuccas are particularly interesting to biologists because of the mutually beneficial relationship between these plants and yucca moths, their only pollinators.
Once yucca comes into bloom in the summer, the tiny female yucca moth visits a flower and collects pollen grains from the stamens, or “male” floral structures.
After packing the pollen into a little ball, which it carries in its mouth, the moth flies to another yucca flower, usually on a different plant.
Next it lays an egg inside the base of the pistil (“female” structure) of the flower. The moth also brushes the top of the pistil with pollen, thus fertilizing the flower and promoting seed production.
After hatching, the yucca moth larva feeds on the developing seeds within the fruit (capsule) of the plant.
Once it’s fully grown, the larva exits the capsule, burrows into the ground, and spins a silken cocoon. When it emerges as a moth the following spring, it mates and the cycle continues.
Meanwhile, the yucca capsule matures and releases whatever viable seeds are left—usually quite a few—ensuring a continuing supply of plants for future yucca moths.
Vicky McMillan, a retired biologist formerly at Colgate University,lives on Hilton Head Island. She can be reached at email@example.com.