abstract architectural backdrop background barrier basic brick brick-wall bricks brickwork cement colored coloring colors coloured colouring colours constructed exterior external firm linear lines mortar perspective perspectives secure security smooth solid standard strength strong style surface surfaced surfaces texture textured textures traditional-brick-wall variation varied various wall walled wallpaper well-built african arid Cacti cactus clumps clusters display distinctive edge edges flora garden-plants green greenery irregular leaves light ornamental patch perennials plants pointed protection ribbed ribbing ribs section shade shape shapes sharp short-spikes small-spines spikes spines spiny succulents sunlight unusual variations variety