Australian competitive compound leaves evergreen tree fast-growing fast-spreading flora flower spikes flowers invasive native native flora native plant ornamental plant prolific prolific seeder Queensland native red spikes schefflera actinophylla spikes terminal inflorescence tree umbrella tree unique flowers appearance background blooms composite composite-bloom curved floral flower flower-head flowering-shrub garden-flower garden-plant leaves leucospermum-cordifolium nature open patterns perennial petals pin-cushion-shape pincushion pincushion-protea proteas red shrub shrubs spike stalks stamens stigma symmetric symmetry