While driving around town with my air conditioner on MAX A/C, practically the only tree I see blooming these days is the resilient retama, with its clouds of yellow, 5-petaled flowers floating on wispy branches that bend in the hot wind. Retama grows well in poor, dry soils, which is why it’s often seen growing on the hills and cliffs near Central Texas highways. When it’s unusual leaflets finally succumb to summer’s heat by defoliating, the thorny, chlorophyll-rich trunk and branches become a still brighter green and continue on with photosynthesis. Retama is a legume, producing 3 to 5 inch long seed pods that can be collected for propagation when they dry and turn brown. Retama is an easy-care tree that provides food and habitat for insects, butterflies, birds and small mammals.