St. John Lily or Poison Bulb is an evergreen perennial from Southeast Asia. In Arriyadh, it is best in partial shade and a humid environment. Broad, dark-green foliage emerges from an enormous bulb more than 25 cm across. It should be buried half in fertile soil that is rich in humus. Numerous arching leaves reach between 1 and 1.5 metres long and some 12 cm wide, and gradually taper to the apex. If damaged by frost, they are soon replaced by new growth. Fleshy roots are easily damaged during transplanting. From spring until autumn, thick pedicels bear umbels of up to 100 large, fragrant flowers with linear white petals that made imaginative people call it Spider Lily. The tubes measure some 7 cm in diameter. Inflorescences appear several times per season and may develop capsules of 5 cm across with globose seeds. All parts are toxic if ingested. If daughter bulbs are not detached, they eventually create an imposing bunch. C. asiaticum tolerates full sun when grown in well-drained, moist soil. Some drought is tolerated by established plants on open ground. In containers, regular irrigation is essential. Potting soil should retain water without getting logged. Watering may be reduced in winter when the plant goes dormant, usually without losing its leaves. Irrigation should be resumed in early spring. Slow-releasing fertiliser should be applied at this time, while potted plants do best with water soluble nutrients every fortnight. In winter, plants may be divided, and new plants may also be achieved by sowing.