521. The list of Leas hardy annual plants embraces many fine flowers, such as different varieties of the African Marigold (Tagetes credal), and of the French Marigold (T. patula); the Amaranth or Love lies bleeding (4nraran thus caudatus), and Prince's Feather (4. hypochondriacus); the rich and elegant Balsams, many varieties, (Impatiens balsamina); different kinds of Chrysanthemum, particularly C. tricolor, and also of Zinnia ; with the Indian corn (Zea mays), and Tobacco plant (Nicotiana tabacum), which arc curious. For these and others a moderate hot-bed is ne cessary, on which they may be soul] in March or April, so as to be ready fur transplanting into the borders in May or June. it is better, however, instead of removing the seed. lings at once to the open border, to prick them into a nur sery border, covered with a canvas awning, or hooped over and protected by mats at night : here they may be allowed to establish themselves and get hardy, for some weeks. In dry weather, frequent watering is essential, especially at the times of transplanting.
522. The list of Tender annual plants is not numerous, unless the balsam and some others from the less hardy list be included, which in the northers part of the island is al ways the case. Many varieties of Cock's-comb (Celesta cristata), with scarlet, purple, and yellow heads, some of the plants dwarfish, others three or four feet high, are ex ceedingly ornamental. The Globe amaranth (Gomphreena globosa) of various sorts, with the Amaranthus tricolor, having each leaf composed of three colours, bright red, yellow and green, are likewise among the more showy of the tender annual flowers. The Egg-plant deserves the same character; not on account of its flower, but of its singular and elegant berry, which has much of the shape and appearance of a large egg, as already noticed (§ 403). The Ice-plant (Mesembryanthemum crystallinum), remark able for its stalks and leaves being covered with crystal line globules like small icicles, and the well-known Humble plant (Mimosa pudica), may also be mentioned. These are raised, in March, in a small hot-bed that is in a pretty strong state of fermentation, and afterwards transferred to one that is larger and of more moderate warmth. In general, the plants are subsequently kept in flower-pots, and are placed near the green-house plants,or perhaps in the green house, the shelves of which they may thus decorate, while the proper inhabitants are abroad. Here too, if properly attended to in regard to watering, they will ripen their seeds, which they seldom do in our climate without the protec tion of glass. A few eock's•combs, globe.amaranthts, and egg-plants, likewise make a fine appearance on the back shelves of a hot-house.
Biennia! Flowers.
523. Some flowers which are, strictly speaking, biennial, often cultivated among the annual kinds : Such are, the Indian pink, (Dianthus Chinensis); the Palma Christi, (Ricinus pahna Christi); and the Sensitive plant, (Mimosa sensitiva). Others are always treated as biennial plants, being kept in nursery rows for the first season, and planted out the next. Some of the most common are, Honesty or satin-flower, (Lunaria annzta,) white and purple flowered ; French Honeysuckle, (Hedysaruni coronarium,) red and white ; Yellow Horned Poppy, (Glazed= luteum); tree primrose, several species, ((enothera bzennis, &c.) ; and
Mullein of diltcient kinds, (Vcrbascum.) particularly the Moth-mullein, ( blattaria,) yellow and white flowered.
Rock-work.
524. In forming a piece of rock-work, it is found very useful to have at least the two or three outward layers of stones composed of moor-stones, that is, of such as have long lain exposed to the action of the weather. At the bases of greenstone and basalt hills very suitable masses may ge nerally be found : those should be selected which have ca vities in them, are unequal on the surface ; keeping in view also that they must be of such shape as to be capable of being piled on each other in a sloping direction without cement. If such weather-worn stones he selected, and mossy earth be used in place of cement, many kinds of ferns, and various cryptogantous plants, will be found to thrive, which would not succeed on sandstone, or on masses of any kind of rock fresh dug from a quarry. Besides, some part of the stones being always seen, the appearance of these is to be considered. Masses covered with lichens, especially Lichen atro-flavus, geographicus, ventosus, pe rellus, and stellaris, are therefore desirable. Pieces of plum-pudding stone and of serpentine have likewise a very good effect; some joints of columnar basalt are in some places introduced, and large petrifactions, or casts in sand stone or limestone, of the trunks and branches of trees. Large shells, too, particularly valves of the Chaim gigas, are occasionally placed in the rock-work ; and among sand in these sonic plants will thrive, such as Cotyledon umbi licus. All plants which grow naturally in a dry soil may be accounted fit for the rock-work. Several species of Di anthus, particularly D. deltoides, armeria, and egesius, are highly ornamental. Red Valerian, (Valeriana rubra,) and a- %%hite variety of it, grow very readily among stones. If peat-earth be used, Erinus alpinus is a desirable plant. It forms close tufts, and produces its pretty purple flowers from April to July ; and when well established, it often ri pens its seed, and sows itself. Different species of Mad moil are suitable, particularly Alyssum saxatile and del toideum. Cerastiutn repens grows freely, but is apt to overrun the other plants : indeed, if it be wished at any time entirely to hide a heap of rubbish with garden plants, this is one of those to be selected for the service. To those already mentioned may be added. Erigeron alPinum ; Cy clamen Europxum and herdeixfolium ; the spring Gen tian, Gentiana verna ; Soldanella alpina ; purple Saxifrage, (Saxifraga oppositifolia,) and double Sengreen, (S. granu-_ Iota, fl. pl.); the borage-leaved Mullein, ( Verbasrum My coni) ; alpine Lychnis, (Lychnis alpina) ; and different spe cies of Primula, P. nivalis, integrifolia, helvetica, and mar ginata. The basil-leaved Soapwort (Saponaria ocymoides) is one of the most beautiful little plants that adorns the flower-garden, and it is peculiarly well suited for rock-work. All the smaller species of hardy Stone-cm-op deserve a place, in particular Sedum album, glaueum, rupestre, ai zoon; and sexangulare ; as well as several species of House-leek, especially the cobweb kind, (Sempervirum arachnoideum). In small flower gardens, the rock-work is -often constructed on the margin of a little pond for hardy aquatic plants.