Salvinia (in honor of Antonio Salvini, 1633-1722, an Italian professor of botany) is a water fern genus, "water spangles" in the vernacular. The plants float in calm and warm, sunny waters. With their clusters of deciduous, rotund fronds, they look like water critters swept about and kept afloat by armies of submersed rootlike strands of foliar tissue (that are actually leaves in disguise). The upper frond surface has water-repellent hairs, and their configuration helps to define the differences between species. Some species are ornamental. Others are invasive. Cultivate the good ones in aquariums and, depending on the cold tolerance, in water features in Zones 6 to 10.
Salvinia minima (smallest) is semihardy in Zones 8 to 10. This small species has petite 1/4- to 1/2-in. (6- to 13-mm) round leaves topped with freestanding hairs. It is from the U.S. Southeast and ranges down through Mexico to South America.
Youthful plants of Sadleria cyatheoides, shown in this year 2000 photo, pioneer through the remains of a 1982 lava flow in Hawaii's Volcano National Park.
Salvinia natans crowds the surface of a water feature in the Stobbe garden.
Salvinia molesta (annoying), which has closed "eggbeater" hairs, is, in keeping with its name, a serious threat to the health of many waterways in the world, with severe consequences for local populations. The spread has been partially brought under control by the appetite of a S. molesta-specific weevil. It is illegal to import or plant this in the United States and most countries of the world. Salvinia auriculata (ear-shaped) is somewhat similar to S. molesta. It is against the law to plant this as well.
Salvinia natans (floating) from Europe and Asia is the hardiest of the lot. Fronds are oblong and hairs are free. It is a novelty for pond and container surfaces in Zones 6 to 10.
Was this article helpful?