Spanish Bayonet

Spanish bayonet (Yucca aloifolia) has an erect trunk, 3-5 in (7.6-12.7 cm) in diameter, reaching up to 5-20 ft (1.5-6.1 m) tall before it becomes top heavy and topples over. When that happens, the tip turns upward and keeps on growing. The trunk is armed with sharp pointed straplike leaves each about 2 ft (0.6 m) long. The young leaves near the growing tip stand erect; older ones are reflexed downward, and the oldest wither and turn brown, hanging around the lower trunk like an Hawaiian skirt. Eventually the tip of the trunk develops a 2 ft (0.6 m) long spike of white, purplish-tinged flowers, each blossom about 4 in (12.7 cm) across. After flowering, the trunk stops growing, but one or more lateral buds are soon formed, and the uppermost becomes a new terminal shoot. Any other buds become branches, but these are usually few, and the plant has an open, airy habit. Spanish bayonet also produces new buds, or offshoots, near the base of the trunk, forming a thicket. There are several cultivars available, including 'Marginata' with yellow margined leaves and a variety (var. draconis) with a branching trunk and wider, recurved leaves.

Spanish bayonet is similar to Spanish dagger or mound lily (Y. gloriosa) but the latter can be recognized by its more branched, interlaced habit which creates an overall moundlike appearance, and by its leaves which are: bluish-green instead of dark green; less rigid, tending to bend downward at the middle; wider and longer; and with smooth instead or rough margins.

Spanish bayonet is native to coastal areas, including sand dunes, shell mounds and shorelines, from North Carolina to Mexico and in the West Indies. It is widely cultivated and naturalized throughout much of the southern US.

WARNING: They don't call it Spanish bayonet because it's named after Señor Bayonet! The tips of the leaves are pointed and sharp! Do not plant Spanish bayonet near walkways, patios or in areas frequented by children and pets. This plant can inflict painful puncture wounds even through heavy clothing!
(credit: http://www.floridata.com/ref/y/yucc_alo.cfm)