Two for the price of one today, Medicago arborea and Euphorbia dendroides. Granted neither of them look at their best right now but that's because they are in the process of shutting down for the summer. In more northern climes some plants have a tendency to 'hibernate' as it were, but here in the Med some have evolved to be summer dormant, to 'aestivate' if you will.
The euphorbia spends the summer months looking like nothing more than a bunch of dead sticks, but then when its body clock decides the time is right, it doesn't even always wait for the first rains, it bursts into leaf and its shining lime-green brightens up the dull winter days.
The tree medick behaves somewhat similarly, although not quite as drastic in simulating death. It is even more colourful in winter becoming a mass of bright yellow followed by ornamental rams-horn seed pods. It is also very useful in the fact that it is capable of fixing nitrogen in the soil due to a symbiotic relationship with the bacterium Sinorhizobium meliloti.