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 ball barrel Cacti cactus desert globe groups plants prickles Prickly shade Spain spanish sphere spiky spines sunlight trees xerophyte alpine Austria blue bud dainty delicate gentian Gentiana gentians group montane patch petal petals small spring tiny wild anthers background exotic filaments flora green long purple Singapore stamen tips tropical unusual whiskers-like white