Rock Fleabane. A mighty mite in the Asteraceae family, this rock crevice dweller was not discovered until 1978 in the Chiricahua Mts in Arizona and later was found 200 miles east in the Black Range of New Mexico. It has been very easy and rock hardy for us and although drought tolerant, adapts to frequent irrigation if given excellent drainage. Small white flowers dot the less than 1" tall ground-hugging mat of small leaves. Perfect for a trough, filling in crevices in stone walks or chinking the seams in a rock wall.