Cassia covesii or Senna covesii
This bushy perennial reproduces by seeds only, and it produces plenty of those on dried pods that I've collected over the last two years. This is a small plant and often comes in wildflower mixes, but I've never seen it for sale at a nursery, probably because it is so common. Actually, this Desert Senna plant is the only thing that came up from a package of summer wildflower seeds I broadcasted two summers ago. The stems are one to two feet high, branching from a woody base, and it flowers from March to October. Some folks find it unattractive when it is not in flower, but I don't it mind at all. It just looks good sitting there greening up a small section of my side yard. I want more of them.
The Desert Senna is an important food source to caterpillars, which helps in the spread of native butterflies. However, I've not seen any caterpillars hanging around this lone plant, ever. In general I don't see a lot of butterflies in my landscape although I have many plants that supposedly attract butterflies, but to date, butterflies have been sparse.
Desert senna is a very common native plant of dry disturbed soil throughout Arizona, which is found along roadsides and waste places, or so they say. I really don't see a lot of it along roadsides in the areas where I travel. It also grows on rocky slopes, mesas, sandy river bottoms, washes in the deserts, and desert grassland ranges. Again, I've not seen any when I've gone into these areas.
I have hundreds of seeds from this plant that I've scattered throughout my garden, and so far, not a one has come up. If the plant is so common here in the desert, one would think I'd have a yard full by now!