GREEN-HOUSE PLANTS. 



319 



telow; flowers arranged in dense terminal heads; 

 liiight pink. Early summer months. 



P. diosmcefolia. — A larger-growing plant than the 

 preceding, which it otherwise resembles; terminal 

 heads of flowers large ; clear rose-colour. Summer. 



P. elegans — A fine showy plant, with broad, some- 

 what ovate leaves ; heads of bloom large and dense ; 

 flowers pale straw-colour. Spring months. 



P. Mendersonii. — An erect species, with slender 

 branches and bright green leaves, and an abundant 

 bloomer ; flowers rich pink. Early summer months. 



P. hispida. — A small-growing plant, with linear 

 oblong-lanceolate leaves, and bluish-white heads of 

 flowers. Spring months. 



P. linifolia. — Leaves linear, dark green ; heads of 

 flowers white. Summer months. 



P. yeippergiana. — A compact-habited plant, with 

 <iensely-set dark green leaves, and large heads of 

 snow-white flowers. Spring and early summer. 



P. rosea. — A small plant of close habit ; leaves 

 linear-lanceolate, heads of flowers deep rosy-pink. 

 Spring and early summer. 



P. spectabilis. — One of the strongest -growing 

 species ; leaves linear-lanceolate, pale green ; heads 

 very large, downy, snow-white. May and June. 



P. spectabilis rosea, — Eesembling type, bearing large 

 heads of downy rosy-purple flowers. May and June. 



Plumbago. — Fast - growing plants, some of 

 which are very handsome ; and amongst them are 

 some peculiar species, or rather, the properties found 

 in them are put to peculiar purposes. P. scandetis, 

 the Herbe du Diable of the island of San Domingo, is 

 very active as a blistering agent, and is said to be 

 used for affections of the liver, whilst P. europea is 

 used by mendicants of the South of Europe to pro- 

 duce artificial sores. P. capensis, if allowed to grow 

 without any pinching back, will make very long 

 shoots, and in this state is admirably adapted for 

 covering pillars or training upon rafters, but if regu- 

 larly attended to in the way of stopping, may be kept 

 in bush form. The leaves are oblong, entire, thin in 

 texture, and pale green ; it produces immense quan- 

 tities of large heads of flowers, which are steel-blue 

 in colour. It flowers more or less during the whole 

 season. Cape of Good Hope. 



Polygala. — A genus of Milk-worts, which give 

 their name to the order Polygalacece ; they are pretty 

 widely distributed, and many of them have valuable 

 medicinal properties. The green-house kinds are all 

 natives of the Cape of Good Hope, and form hand- 

 some specimens. 



Polygalas are aU pkints of free growth and easy 

 culture, and thrive best in a compost of two parts 

 peat, one of loam, and one of sand. After the 

 flowerin" season is over the knife should be applied 



freely, or the plants wiU become straggling, and 

 lose their bottom leaves. 



P. Dalmaisiana is a vigorous grower, with purple 

 flowers; the lower petal in all the species is keel- 

 shaped and beautifully fringed, which gives the 

 members of this genus a very distinctive character. 

 May and June. 



P. myrtifolia grandiflora. — Leaves smooth, oblong- 

 acute ; racemes of purple flowers, which are much 

 larger than in the original species. Summer months. 



P. oppositifolia major. — Leaves opposite, oblong- 

 acute ; flowers bright purple ; an improved form of 

 the species. May and June. 



Prinmla sinensis. — These are among the 

 most popular and useful of all our autumn, winter, 

 and spring blooming greenhouse plants. There are 

 now many improved varieties, chiefly the result of 

 careful selection and crossing, though obviously all 

 obtained from the original pale pink species intro- 

 duced in 1820. We have now a rich variety of 

 flower and foliage of every shade of colour, from 

 purest white to deep crimson; and of all shapes, 

 forms, and degrees of doubleness — flmbriated, ser- 

 rated, single, semi-double, double, almost to perfect 

 spheres. The old double white is, however, stiU one 

 of the best, the readiest propagated, and easiest 

 grown. The real double varieties can only be in- 

 creased through layers or cuttings ; while the single 

 and semi-double varieties are readily raised from 

 seed. To ensure a long succession of bloom through 

 the early autumn and winter, successional sowings 

 may be made from March to May. Sow in well- 

 drained shallow pans, pots, or boxes, in a mixture 

 of equal parts of leaf -mould, peat, and sand, and cover 

 lightly with fine soil or sand. Cover with a square 

 of glass to preserve moisture and protect the seeds. 

 A temperature of about 5.5° is most favourable to 

 their germination. So soon as up remove the glass, 

 and gradually inure to light and air in frames, or on 

 greenhouse shelf. "When the plants have formed 

 three 'leaves, prick off or pot singly in smaU pots. 

 So soon as these are filled with TOots,"shift again into 

 larger, or at once into five-inch pots, a size suffi- 

 ciently large for blooming the stock of Chinese 

 primroses. For the last shift a mixture of equal 

 parts of peat, loam, and rotten manure, or leaf- 

 mould, with a liberal addition of sand, is the best. 

 Let the base of the plants rest on the soil ; they must 

 not be buried ; and it is good practice to place three 

 small stakes in a triangle round the trown to keep 

 the plants steady, as they get top-heavy with foliage 

 and bloom. A temperature of 50° to 55° is not only 

 the most suitable for growth, but also for blooming, 

 though most of the doubles — notably the old white 

 — will bear five degrees more heat. 



