Asia fly green nature plants small traps Venus 2012 6th astronomy Copenhagen Denmark june Nyberg passage passing planet sun carnivorous catch danger digests Dionaea muscipula Flytrap insect plant red trap botanic garden botanics devour eating flies flower flowers glasgow grip insect eating nutrition savage attract-prey attracted attraction carnivore carnivorous-plants clumps clusters coloring colors colouring colours cover digest digested digesting display distinctive edge edges enzymes flora funnel herbaceous insect-trap insects nectar-like-secretions nutrient-source nutrients operculum passive-trap perennials pitcher-plants pitchers pitfall-traps prey proteases rims slippery species unusual variations variety vegetation veins