Hesperocallis undulata aka Desert Lily

Hesperocallis undulata is a desert bulb. It belongs to the Asparagaceae family. Its names include desert lily, ajo lily, and evening beauty. It grows wild in southern Nevada and western Arizona. Its native range also covers northwestern Mexico. Plants For A Future lists California in its range too. It grows on dry, sandy flats and gentle desert slopes. It also grows in creosote bush scrub below 2,460 feet [750 metres].

The plant grows at a slow rate from a deep underground bulb. It reaches about 3 feet [0.9 metres] tall. Its spread reaches about 1.3 feet [0.4 metres]. The bulb stores food and helps it survive long droughts. It stays beneath the sand through the hot desert summer. This depth shields it from heat and grazing animals. Most bulbs measure about 0.07–0.2 feet [0.02–0.06 metres] across. Old plants may have larger bulbs.

White flowers bloom after winters that suit the plant's growth. Plants For A Future gives February to March as bloom time. Flowers may last just a few weeks before growth disappears. The plant does not bloom each year on a set schedule. Each flower has both male and female organs. The flowers give insects nectar and pollen. Insects move pollen between flowers. Small birds and rodents may eat the seeds. Its scent gives the plant value in gardens.

In gardens, it needs sun and soil that drains well. Sandy or loamy soil suits it. The soil can be mildly acid or mildly alkaline. Neutral soil suits it too. It can grow in dry or moist soil and withstand drought. Plants For A Future gives USDA zones 8–11. That source also lists UK zone 9. Suggested sites include beds near walls that face south or west. For their first two years, seedlings need deep pots. Disturb them as little as possible during this time. Give little water while the plant rests and does not grow. Do not let the compost dry out fully.

People have used the bulb as a starchy food. They can eat it raw or cooked. Cooking makes its taste and texture better. Its mild taste recalls potato or chestnut, not garlic. Taking the bulb kills the plant. Plant numbers take a long time to recover. Some parts of its range have legal protection. Leave wild plants alone where the law bans collection. The supplied evidence does not show whether it is safe for pets. It names no specific pests or diseases. Plants For A Future lists no known uses as medicine. It also reports no risk of the plant becoming a weed.