architecture building Copenhagen cupola danish Denmark dome garden glass glasshouse greenhouse hothouse Kobenhavn landmark ornamental plant tropical allium ball England english flowers Great Britain head natural nature onion pink purple stem trellis ancient decorative elements historical history old ornate stone trough walled Acer autumn color colour fall leaf leaves orange red tree yellow aquatic plant hedges kent lily pads Penshurst Place pond topiary water branches fruit green magnolia bush clipped design dordogne formal France french park shrub blue Cacti cactus clouds clusters edge edges flora frilled frills fruits garden display garden plant irregular light long ornamental plants points protection ribbed ribbing shade shadows shape shapes sharp short spikes sky small spines succulent sunlight sunshine surface surfaces tall texture textures unusual