These closely allied plants require similar treatment, and may be suitably mentioned together. The connection is so close indeed that several of the species of either bear in gardens the generic name of the other. The stove species should always be kept moist, while the plants which do with greenhouse temperature need to be kept dry while at rest in winter. The pots must be large and filled with good loam and leaf-mould, with a dash of silver sand. The bulbs should be just below the surface. A few, which have been also known as Ismenes, are understood to be hardy in favoured places. Ordinary stove heat will suit the following:--Hymenocallises:--andreana, Choretis, expansa, lacera, ovata, macrostephana, maculata, speciosa; and Pancratiums verecundum and zeylanicum. For the greenhouse there are:--H. Amancaes, calathina, harrisiana, littoralis (syn. adnata), macleana (the hardiest), tenuifolia. In looking over catalogues to order these, Pancratium, Hymenocallis, and Ismene should all be referred to on account of the uncertainty about the nursery names.
These are best known because of the popular R. africana, often called Calla æthiopica, the Arum Lily, or Lily of the Nile. All the species like a very rich soil, and a plentiful supply of water while growing. R. africana can be grown as a hardy aquatic in some warm districts in these islands if the crowns are well below the depth to which the water is frozen. It is, however, most grown as a greenhouse or window plant, especially when white flowers are wanted early. After flowering, it may either be planted out in trenches in the garden, or dried off and started in the same pots. Potting may be done about September, and the plants grown in ordinary greenhouse temperature. Albo-maculata, hastata, and melanoleuca are less beautiful. Adlami, elliotiana, Pentlandi, and Rehmanni are all newer and of much beauty, the second and third having yellowish flowers.
Although Sprekelia formosissima, known also as Amaryllis formosissima, the "Jacobea Lily," is sometimes recommended as a half-hardy bulb, this is of doubtful expediency, and it is better to treat it as a cool greenhouse bulb and to grow it in pots. It is sometimes planted out on a sunny border below a wall in April and lifted in September, but we recommend planting it in turfy loam, well-decayed manure and a little sand, in pots, and treating it like the Hippeastrum, but in a rather lower temperature. It grows about two feet high, and has crimson or white flowers about June. There is another named S. Cybister, which has red flowers about April.