Buddleja marrubiifolia
Buddleja marrubiifolia, commonly known as the woolly butterflybush, is a perennial shrub which is endemic to the Chihuahuan Desert from southern Texas to San Luis Potosí in Mexico, where it grows on limestone and gypsum soils in canyons and arroyos at elevations of elevation. The species was first named and described by George Bentham in 1846. Description. "Buddleja marrubiifolia" is a dioecious multi-branched shrub that is high with greyish to blackish rimose bark. The young branches are terete and tomentose, bearing ovate to rhomboid leaves that are long by wide, membranaceous to subcoriaceous, and densely tomentose on  both surfaces. The inflorescence is a terminal globose head which is in diameter, comprising 35 flowers, deep yellow turning orange; the corollas are long. Ploidy: "2n" = 38. Cultivation. The shrub is cultivated throughout Tucson, Arizona to attract butterflies. It is also planted as an ornamental in Hawaii. The shrub is in commerce in France, sold by several specialist alpine nurseries, and was introduced to the UK in February 2013, with one small plant acquired by the Longstock Park Nursery, NCCPG national buddleja collection holders, and another by the Royal Botanic Garden Edinburgh. Hardiness: USDA zone 7.