Desert willow (Chilopsis linearis)
Sometimes plant names are just plain confusing. The desert willow is not a true willow, but it does grow in deserts. Actually, desert willow is in the trumpet creeper family (Bignoniaceae), which has many showy-flowered species found mostly in the tropics. Catalpa (Catalpa bignonioides and Catalpa speciosa) and trumpet creeper (Campsis radicans) are native North American species closely related to desert willow.
Desert willow, which grows as a shrub or small tree, is at home in desert arroyos. An arroyo (literally creek in Spanish) is a usually dry creek bed or gulch that temporarily fills with water after heavy rains. Each rain gives the desert willow a good watering and it responds with a spurt of new growth and new flower clusters at the end of its branches. It may have two or three growth spurts during a wet summer.
Desert willow has become a popular landscaping plant in the Southwest. It grows rapidly when regularly watered, but also tolerates long periods without water making it a good low-maintenance plant. And, its beautiful flowers add to its appeal. The flowers are usually whitish with a tinge of purple, but cultivars have been selected with colors ranging from white to deep purple.
Horticulturists have used desert willow to come up with a completely new cultivar, the chitalpa. This tree is a sterile hybrid between desert willow (Chilopsis linearis) and southern catalpa (Catalpa bignonioides). The chitalpa combines the good features of both parents. It can grow in more northern climates than desert willow, it is more drought tolerant than catalpa, and as a hybrid, it makes no fruits; and, yes it still has those glorious flowers.