Depending on the authority, yuccas are usually placed in the lily family (Liliaceae) or the agave family (Agavaceae). The name Yucca is derived from "yuca," a Carib Indian name for the cassava or tapioca plant (Manihot esculenta) of the euphorbia family (Euphorbiaceae). Yucca is also the creole word for cassava. "Yuca" is not to be confused with the lovely yellow-flowered morning glory (Merremia aurea) of the Cape Region of Baja California. Apparently the connection with starchy cassava roots is that yucca buds and young flower stalks of are also roasted for food. Yuccas are trunkless shrubs with rosettes of stiff, sword-shaped leaves arising at ground level, or tree-like with distinct trunks and limbs. Examples of the rosette forms include Spanish bayonet (Y. baccata) and chaparral yucca (Y. whipplei). Tree-like forms include the Joshua tree (Y. brevifolia) of the California and Arizona desert region, and tree yucca or "datillo" (Y. vallida) endemic to southern Baja California.

Pandanus is a genus of widespread, dioecious, palm-like trees. The commonly cultivated P. utilis is native to Madagascar. It is currently being grown in the greenhouse and will be planted in the Palomar Collerge Arboretum. Another species, P. tectorius is native throughout the rocky and sandy shores of Polynesian atolls and islands. This tree belongs to its own monocotyledonous family, the Pandanaceae. Although it is called "screw pine," it is not related to the pine family (Pinaceae). Note the conspicuous prop roots at the base of the trunk which support these plants in water-logged soils and strong winds. Pandanus is second only to the coconut palm (Cocos nucifera) in importance in Polynesia and Micronesia. The fibrous leaves are used for baskets, floor coverings, mats, and for thatching houses. Ancient Polynesian mariners used the leaves to make sails for their outrigger canoes. Native Hawaiians also used the leaves of pandanus or "hala" to weave their original baskets and mats. This species is sometimes listed as P. odoratissimus, a name derived from the fragrant pollen of male plants.