Texas Sage

The Leucophyllum frutescens, or Texas Sage, is a compact silver-grey shrub out of the Chihuahuan Desert, and it is among the most useful plants available for hot alkaline ground. Small felted leaves give the plant its pale colour, and every rise in humidity triggers a flush of bell-shaped magenta to lavender flowers, which is why it is also called the barometer bush.
It asks for sharp drainage, full sun and very little water, and it will refuse heavy irrigation outright, which makes it a natural fit for medians, verges and desert schemes.
Texas Sage is one of the few shrubs that will flower repeatedly on a hot alkaline median with almost no water reaching it.