Wikipedia
Manfreda is a genus of flowering plants in the family Asparagaceae, subfamily Agavoideae. Along with Polianthes, members are commonly called tuberoses. Some authorities place Manfreda in genus Polianthes, while others group place both genera in Agave. The generic name honours 14th-century Italian writer Manfredus de Monte Imperiale.
They are native to the southern United States, Mexico, and Central America.
Like others in its family, tuberoses have rosettes of leaves branching from a very short stem, and flowers at the end of a long stalk. The flowers are tubular and whitish, yellow, green, or brownish, with lengthy stamens.
The spotted manfreda, also called Texas tuberose ( Manfreda maculosa) is notable for having silvery-green leaves covered with purple spots and is a popular xeriscape plant in the Southwest US.