Yuccas have been blooming in Columbia over the past week; most are Adam's Needles, natives of the Coastal Plain from New Jersey to Alabama. Like all yuccas, they are characterized by a rosette of tough, evergreen, pointed leaves and a fast growing flower stalk that yields large, bell-shaped blossoms; most species produce white or cream-colored flowers though some are fringed with purple, green or reddish hues. Some yuccas, like Adam's Needle and the "bear grass" yucca of the Great Plains, do not form basal stems while others, like the Joshua Tree of the Southwest, have prominent, branching trunks.
Contrary to popular perception, yuccas are not cacti; rather, they are members of the agave family and are closely related to lilies. All are native to the Americas and at least 60 species are found in dry or sandy habitats of the U.S. and Mexico; some species, including Adam's Needle and the Spanish Bayonet, are widely planted as ornamentals and, if placed in well-drained soil, can tolerate a wide range of climates.
For naturalists, the most interesting fact about yuccas is their symbiotic relationship with the yucca moth, which actively pollinates these plants. Rather than passively transferring pollen in the act of feeding, the female yucca moth brings pollen from one plant to another, directly fertilizing the recipient; in concert, she lays some of her eggs within the flower and, when they hatch, the larvae feed on the developing seeds. A natural balance insures that not all of the seed is destroyed and, when the pods dry and split, the viable seeds are spread about by wind or by animals that feed on the pods.