angles appearance blue branch branches branching Cacti cactus clusters columnar edges flora frilled frills fruit fruiting garden-display green green-fruit height high irregular large leaf light long multiple-branched perennial points prickles Prickly protection ribbed ribbing shade shadows shapes sharp sky spikes spines succulent sunlight sunshine surface surfaces tall textures Unripe unusual appearances arid clumps colorful coloring colors colourful colouring colours display edge garden-plants greenery leaves ornamental perennials plants pointed ribs shape short-spikes small-spines spiny succulents variations variety barrel barrel-cactus round abundance ageratum annuals bedding bloom bloomimg blooms blue-billy-goat-weed blue-billygoat-weed borders chick-weed color colored colour coloured containers cultivars cultivated edging exotic florets floss floss-flower flower flowers fluffy fuzzy goatweed hardy leafy potting-plants profusion purple rock-gardens soft weed wild attract-prey attracted attraction carnivore carnivorous carnivorous-plants cover devour digest digested digesting distinctive enzymes funnel herbaceous insect-trap insects nectar-like-secretions nutrient-source nutrients operculum passive-trap pitcher-plants pitchers pitfall-traps prey proteases rims slippery species trap vegetation veins