Asparagus is a perennial garden plant belonging to the Lily family (Liliaceae). While approximately 300 varieties of asparagus have been noted, only 20 are edible.
Asparagus, its fleshy spears topped with bud-like compact heads, is often thought of as a luxury vegetable, prized for its succulent taste and tender texture. It is harvested in the spring when it is 6 to 8 inches tall. While the most common variety of asparagus is green in color, two other edible varieties are available. White asparagus, with its more delicate flavor and tender texture, is grown underground to inhibit its development of chlorophyll content, therefore creating its distinctive white coloring. It is generally found canned, although you may find it fresh in some select gourmet shops, and it is generally more expensive than the green variety since its production is more labor intensive. The other edible variety of asparagus is purple in color. It is much smaller than the green or white variety (usually just 2 to 3 inches tall) and features a fruitier flavor. It also provides benefits from phytonutrients called anthocyanins that give it its purple color. With prolonged cooking, the purple color may disappear.