In the foothills one of the most conspicuous flowering species nowadays is the bush or small tree whose rain- soaked flowers, slender fruit and pinnate leaves are seen below:
Where the species enters Texas and Arizona it's sometimes called Yellow Bells, as well as a host of other names. It's TECOMA STANS, a member of the same family as Trumpet Creeper and Catalpa, the Bignonia Family. It occurs in arid habitats as far south as Argentina. Here in places it's weedy, forming big blobs of yellow along roads. In fact, despite it being the Official Flower of the US Virgin Islands, the plant is weedily invading Florida, southern Africa, Pacific islands and, of course, Australia. Its slender fruit pods produce abundant small, wind-dispersed seeds with papery wings making it easy for the species to advance into new territory.
My "Plantas Medicinales de México," calling the plant "Tronadora," devotes extra space to the species because traditionally here it's been considered an antidiabetic -- it lowers the blood-sugar level in diabetics. In diabetic mice, extracts of Yellow Bell have been shown to provide significant effects, as reported here.