384 FLOWERS OF GARDEN AND GREENHOUSE 



house. Their bold, beautifully-coloured flowers make them highly- 

 desirable plants, but their uncertainty of germination and settlement is 

 a bar to their popularity. Most of them refuse to grow when divided, 

 and bought seeds are slow to germinate. Seed of one's own harvesting 

 sown as soon as ripe is more promising, but even this takes six months or 

 more to show any result, and purchased seed may require several years. 

 The best plan is to buy plants from a nursery and seek to establish 

 them, afterwards raising seedlings from your own seed. A well-drained 

 compost of three-parts loam to one of peat, with the addition of small 

 stones, is best for them, and porous stones should also be pressed into the 

 soil close round the plants. The drainage must be perfect, for Gentians 

 require much water when growing, but cannot endure stagnant moisture. 

 Description of Gentiana acaulis, the Gentianella, two-thirds of the 



Plate 183. natural size. Fig. 1, section of flower, natural size. 



Among other genera of Gentiaxej'. may be mentioned the 

 following :— 



SABBATiA(named after L.Sabbati, an Italian botanist of the eighteenth 

 century). American Centauries. A genus of about thirteen species of 

 hardy annuals or biennials, with shortly tubular wheel-shaped flowers 

 and opposite leaves, affecting moist and bogg}^ situations, but of rather 

 capricious growth in gardens. Natives of North America and Cuba. 

 S. campestris, introduced from Texas (1855), is about a foot high, with 

 yellow-centred, rose-coloured flowers in clusters, S. cahjcosa has leafj- 

 calyx -lobes and deep red corolla (introduced 1812); and S. stellaris has 

 awl-shaped calyx-lobes and bright rosy-purple corolla (introduced 1817). 

 Seed sl\ould be sown thinly in pots, or on a shady border, as soon as 

 ripe. Flowers throughout following sununer. 



SwKKTrA (named in honour of I. Swert, a Dutch cultivator of bulbs, 

 s.'ventrrnth century). A genus of alxnit forty species of erect herbs, 

 natives of Europe, Asia, and Africa. S<'vcral species are cultivated in 

 greeuh(jus,.s. .S. rur;/ .nh,>s,, (introduced tVom India, 1836) is an annual 



annual with white flowers spotted with purple or green : June to August. 

 S. petri'vis \s a hardy perennial from Euroix\ witli <krk spotted blue 

 flowers : July. Seeds of the two first sliould be sown on a hot-bed in 

 spring, and the seedlings pricked out where they are to flower : those 

 of S. pvrenniii should be sown on pans of peaty soil, and afterwards the 

 plants should have a moist bog-like situation for growth. 



Menyanthes (Greek, men , a month, and anthos, flower). Buckbean. 

 A genus of two species of hardy perennials, one American, one British, 



