Linnaea Borealis.—­A rare, native, evergreen creeping perennial.  From July to September it bears pale pink flowers; it makes a pretty pot-plant, and also does well in the open when planted in a shady position.  It enjoys a peat soil, and is propagated by separating the creeping stems after they are rooted.  Height, 11/2 in.

Linum (Flax).—­This succeeds best in rich, light mould.  The Linum Flavum, or Golden Flax, is very suitable for pot culture; it grows 9 in. in height, and bears brilliant yellow flowers.  It requires the same treatment as other half-hardy perennials.  The Scarlet Flax is an annual, very free-flowering, and unsurpassed for brilliancy; easily raised from seed sown in spring.  Height, 11/2 ft.  The hardy, shrubby kinds may be increased by cuttings placed under glass.  A mixture of loam and peat makes a fine soil for the greenhouse and frame varieties.  They flower from March to July.

Lippia Reptans.—­A frame creeping perennial which flowers in June.  It requires a light soil.  Cuttings of the young wood may be struck under glass.  Height, 1 ft.

Lithospermum Prostratum.—­A hardy perennial, evergreen trailer, needing no special culture, and adapting itself to any soil.  It is increased by cuttings of the previous year’s growth, placed in peat and silver sand, shaded and kept cool, but not too wet.  They should be struck early in summer, so as to be well rooted before winter sets in.  Its blue flowers are produced in June.  Height, 1 ft.

Loasa.—­The flowers are both beautiful and curiously formed, but the plants have a stinging property.  They grow well in any loamy soil, and are easily increased by seed sown in spring.  Flowers are produced in June and July.  Height, 2 ft.  Besides the annuals there is a half-hardy climber, L. Aurantiaca, bearing orange-coloured flowers, and attaining the height of 10 or 12 ft.

Lobelia.—­These effective plants may be raised from seed sown in January or February in fine soil.  Sprinkle a little silver sand or very fine mould over the seed; place in a greenhouse, or in a frame having a slight bottom-heat, and when large enough prick them out about 1 in. apart; afterwards put each single plant in a thumb-pot, and plant out at the end of May.  As the different varieties do not always come true from seed, it is best to propagate by means of cuttings taken in autumn, or take up the old plants before the frost gets to them, remove all the young shoots (those at the base of the plant are best, and if they have a little root attached to them so much the better), and plant them thinly in well-drained, shallow pans of leaf-mould and sand; plunge the pans in a hotbed under a frame, shade them from hot sunshine, and when they are rooted remove them to the greenhouse till spring, at which time growth must be encouraged by giving a higher temperature and frequent syringing.  They may then be planted out in light, rich soil, where they will bloom in June or July.  Height, 4 in.