arching Australian black boy bush bushland evergreen flowering fragrant grass tree layers outback plant resin slow-growing spike spiny leaves stout trunk unusual Xanthorrhoea Xanthorrhoea preissii angles appearance black-boy bush-plants corner garden grass-tree ground-cover mantle multiple-flower-stalks native-plants plants raised-garden spikes spiny-leaves stout-trunk tall trimmed Xanthorrhoea-preissii background brown curly dead drought dry gras tree leaf leaves texture vegetation circular dried layered remainder rim abstract descending fronds hanging lines spiky strands green light standing straight sunlight upright wallpaper