This low maintenance, exotic-looking succulent thrives in home environments. In fact, its one of the recommended plants to filter out indoor toxins, especially formaldehyde-based pollutants found in carpeting, furniture, cleaners and foam insulation. Sansevieria cylindrica, also called Spear Sansevieria, is an easy-to-grow ornamental plant that requires watering only once or twice a month. Each round, smooth, grayish-green leaf is 1.5 thick with dark green stripes and a pointed terminal end. The stiff upright leaves reach 2-5 in height. Allow to dry out between waterings.