abundant angles appearances castor-beans castor-oil castor-oil-plant castor-seeds cluster clusters common cotyledons Euphorbiaceae fast-growing flower flowers foliage highly-toxic inflorescences invasive large large-leaves leaf leaves medicinal palm-of-Christ palma-Christi poison poisonous ricinus-communis seed-pods seedhead shrub shrubbery spiky-green-seed-capsule spiny surface surfaces textured textures toxic toxins vegetation wasteland-weed weed widespread arid Cacti cactus clumps coloring colors colouring colours display edge edges flora frilled frills garden-display garden-plants green irregular light ornamental perennials plants pointed protection ribbed ribbing ribs shape shapes sharp short-spikes small-spines spikes spines succulents sunlight unusual variations variety various barrel barrel-cactus round symmetry colorful colourful