Any plant of the order Cactacæ, as the prickly pear and the night-blooming cereus. See Cereus. They usually have leafless stems and branches, often beset with clustered thorns, and are mostly natives of the warmer parts of America.
The official domestic street window display plant in Belgium. Not just any type of cactus mind you, but these long tall spike-free green ones that have narrow pointed leaves and reach for the sky between the lace curtains and the window pane. Very attractive and original.
Cactus are bad Feng Shui when placed inside the home or at the front door as thorns capture and contain sha within the home. However, its an effective plant in the garden as it protects your home. Thorns or needles counter sha chi (negative energy) headed in your direction.
Cactus is a general, modular, parallel environment for solving systems of partial differential equations. The code has been developed over many years by a large international collaboration of numerical relativity and computational science research groups and can be used to provide a portable platform for solving any system of partial differential equations.