altitude canada cluster flower group high little minute montane mountain natural nature patch plant Rockies Rocky Mountains small tiny yellow abundant angles appearances castor-beans castor-oil castor-oil-plant castor-seeds clusters common cotyledons Euphorbiaceae fast-growing 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