Agave tequilana planting these shoots; this has led to a considerable loss of genetic diversity in cultivated blue agave. It is rarely kept as a houseplant, but a 50-year-old blue agave in Boston grew a stalk requiring a hole in the greenhouse roof and flowered in the summer of 2006. Tequila is made only from a specific cultivar of "Agave tequilana" called 'Weber Azul'. This cultivar is larger and blue-gray in color compared to the smaller and green normal "A. tequilana". It is a rapid grower and prolific offsetter in keeping with its agricultural advantages. Tequila is produced by removing the heart
Agave parviflora pollinated by bees such as bumblebees. This species is the smallest agave in Arizona and is sought by collectors. For this reason the species has declined in its native habitat. There are only about two dozen natural populations in Arizona. Other threats to the species include road construction and mining. The plant is valued in cultivation and has gained the Royal Horticultural Society's Award of Garden Merit. Subspecies of the plant include ssp. "parviflora" and ssp. "densiflora". Agave parviflora Agave parviflora is a species of succulent perennial flowering plant in the asparagus family, known by the common names Santa Cruz