Calochortus ambiguus aka Doubting Mariposa Lily

Calochortus ambiguus is a small bulbous perennial in the lily family. Its common names include Arizona mariposa lily and doubting mariposa lily. Its native range runs from southern Utah to southwestern New Mexico and Sonora, Mexico. It also grows in Arizona. It lives on dry slopes, mesas, and open desert grasslands. These sites often support agaves, yuccas, and grasses. Its habitat lies about 3,280–6,560 feet [1,000–2,000 metres] above sea level.

The plant grows from a small, egg-shaped bulb. Garden size is given as about 0.7 feet [0.2 metres] tall. Its spread is about 0.3 feet [0.1 metres]. A fuller account gives stems reaching 0.3–1.3 feet [0.1–0.4 metres]. These thin stems seldom branch and carry one to three narrow, grass-like leaves. The plant grows at a moderate rate. Its small size suits close viewing in a native garden.

The cup-shaped flowers open in spring. Each has three broad petals and three narrower sepals. Petal colours range from white or pale pink to lavender. Dark veins and marks add contrast inside the flower. The inner surface may also have spots or fringes. Each petal has a clear nectar gland near its base. Native solitary bees do most of the pollination. Small butterflies and beetles also visit the flowers. Upright, three-angled capsules follow flowering and turn tan as they dry.

Grow this lily in full sun with good drainage. Sandy or loamy soil suits it, including soil low in nutrients. It accepts neutral to alkaline ground, even strongly alkaline soil. It can grow in dry or moist soil and withstand drought. The source lists USDA hardiness zones 6–9. Sow seed in autumn, or divide bulbs after dormancy. Suggested uses include dry native gardens and wildflower restoration. Its flowers provide food for native insects. Ground squirrels and pocket gophers may eat the bulbs.

Cooked bulbs are edible and contain starch. Apache and Hopi people used them as food, roasting or boiling them. Cooking gives the bulbs a soft texture and mild taste. Their small size makes gathering a meal slow work. Raw bulbs may upset the stomach because they contain saponins. Do not gather plants from protected habitats. The source records no known medicinal uses. It also reports ceremonial use of the flowers as offerings.