Yucca baccata

You buy the plant in the picture.

Because Yucca baccata occurs in a wide range in much of the south western USA and northern Mexico, it is a variable species.
There are small-trunked cluster forming plants that develop rosettes of 5-50 heads, developing clumps way over 2 meters.
In other areas plants form single trunks up to 2 m. Single trunks often curve and branch out.
The leaves also vary considerably in colour: there are blue-green forms and grey-green from western Texas and bordering regions in New Mexico and completely blue forms from Nevada and Arizona.
The leaves from Yucca baccata are mostly straight and rigid, but some populations have twisted leaves.
The size of the leaves from Texas plants are 30-50 cm long and 3 cm wide, others can be 80 cm long and 5,5 cm wide.
The inflorescence is in the beginning of an attractive white and purple colour and about 80 cm long, the flowers are 4-10 cm long and about 2,5 cm wide, and produce very large fleshy, eatable fruits (seed pods).
Normally the panicle measures twice the length of the leaves.
Y.baccata is a very cold hardy yucca down to -29°C what makes it a widely used plant.