Yucca is a genus of perennial shrubs and trees in the agave family, Agavaceae. Its 40-50 species are notable for their rosettes of evergreen, tough, sword-shaped leaves and large terminal panicles of white or whitish flowers. They are native to the hot and dry (arid) parts of North America, Central America, South America, and the Caribbean. Early reports of the species were confused with the cassava (Manihot esculenta). Consequently, Linnaeus mistakenly derived the generic name from the Carib word for the latter, yucca.
Yuccas have a very specialized, mutualistic pollination system, being pollinated by the yucca moth; the insect purposefully transfers the pollen from the stamens of one plant to the stigma of another, and at the same time lays an egg in the flower; the moth larva then feeds on some of the developing seeds, always leaving enough seed to perpetuate the species.
Source : http://en.wikipedia.org/wiki/Yucca
See Also : Online Flowers Ordering, Flower Hong Kong, Hong Kong Flower