Scientific: Zephyranthes candida 
Common: rain lily, fairy lily, Autumn rain-lily, Peruvian swamp-lily
Family: Amaryllidaceae
Origin: La Plata region of South America

Hardiness zones
Sunset
1-9, 12-24
USDA 5 -11

Landscape Use: Small accent herb for mixed borders, small-scale ground cover, containers, atriums, entry ways, mesic landscape designs

Form & Character: Herbaceous perennial, evergreen, diminutive and refined, "monkey grass with big blooms"

Growth Habit: Moderately slow to clump to 8" in height by 15" spread

Foliage/Texture: Basal clumps of linear, succulent foliage that are more persistent than leaves of other Zephyranthes species; fine texture.

Flowers & Fruits: The 2-3" white crocus-like flowers are very showy.

Seasonal Color: Fall to winter cool season flowers blooms are mostly light colored to white.

Temperature: Heat sensitive in Phoenix especially in combination with drought; cold tolerant.

Light: Partial sun in Phoenix is best, though will thrive in full sun when placed in a mesic "green" landscape situation. Avoid afternoon western sun or amplified reflected sunlight conditions.

Soil: Fast draining, organic and loamy soils are best. Rain lily is salt sensitive.

Watering: Regular to keep soil evenly moist

Pruning: Removal of spent flower heads that's needed.

Propagation: periodic division of enlarged clumps, seed

Disease and pests: Spider mites

Additional comments: Presently, rain lily is a popular herbaceous perennial for small spaces with close human contact for that "up close and personal look". Given it's Phoenix and we're in 'a desert', I wonder if it's popularity will be short lived. The genus name "Zephyranthes" means "Flower of the south wind". "Candida" means "white".

Zephyranthus grandiflora has brillant large flower in summer; needs partial to full shade.