Petalidium 



( 180 ) 



Petunia 



PETALIDIUM (syn. PSBUDO-BABLERIA). 



Unarmed stove shrubs (or I. Acanthacea;). 

 Propagation, by cuttings, in spring. Soil, loam two 

 parts, leaf mould one part, and sand one-sixth. 

 Pinch once to obtain well-furnished plants. 



Principal Species : 



barlerioides, 3' to 4', Je., st. ev., wh. 



PETALOSTEMON. (PRAIRIE CLOVER.) 

 Hardy or half-hardy herbs, perennials for the 



most part (ord. Leguminosse), allied to Dalea. 



Propagation, by division of the roots in spring. 



Any ordinary garden soil. 



Principal Species : 



candidus, 1', Jy., hdy. violaceus, 1', Jy., hdy. 



per., wh., leaflets seven P er '> ra P ur> > leaflets 



to nine. five. 



PETASITES. 



Hardy herbs (ord. Composite), with woolly leaves 

 and more or less fleshy rhizomes. Fragrans, the 

 Winter Heliotrope, and officinalis, the Bog Rhubarb, 

 or Butter Bur, are well-known plants. The former 

 is occasionally employed as a pot plant, for flower- 

 ing in the cool conservatory in winter. It makes 

 an excellent fringe to rockery bordered fountain 

 basins or miniature waterfalls. OiBcinalis (syn. 

 vulgaris) makes a charming picture, when in full 

 vigour, by the banks of ponds or streams in the 

 wild garden. If a light but rich soil is given the 

 leaves attain to enormous proportions and are quite 

 tropical in appearance. They are of spreading 

 habit, and when unconflned in a garden fragrans 

 often becomes a nuisance. Propagated by division. 

 Any garden soil will do. 



Principal Species and Variety : 



fragrans, 6", Feb., wh., gigauteus, 6", the Ivs. 



fragrant (syn. Tussilago have edible petioles, 



fragrans). Winter like Rhubarb ; m Japan 



Heliotrope. they are used for make- 



frigidus, 6", Ap., My., shift umbrellas, 



wh. (tyn. Tussilago officmalis, 1' to 5', Mch., 



frigida). My. , wh. (XI/HS. Tussi- 



japonicus, wh. (syn. lago Petasites and T. 



Nardosmia japonica). vulgaris). Bog Rhu- 

 barb, Butter Bur. 



PETIVERIA (syn. MAPA). 



One species (ord. Phytolaccacea?), a branching 

 stove shrub, which may be increased by cuttings 

 of the half-ripened shoots. Soil, loam and peat, 

 with sand. 



Only Species and Variety : 



alliacea, 2' to 3', Je., octaudra. Ivs. smaller 

 st., wh. Guinea-hen and dwarfer (syn. 



Weed. octaudra) . 



PETREA (syn. PETR^EA). 



Stove shrubs, including twiners (ord. Verben- 

 acese), from tropical America, and several of them 

 of great beauty. Propagated by cuttings, in a 

 light, sandy soil, in bottom heat, covered by a bell- 

 glass. Soil, turfy loam three parts, leaf mould one 

 part, and old Mushroom bed manure one part, with 

 one-sixth sand. 



Principal Species : 



arborea, 12', Je., st., bl., volubilis, 12', Jy., st. cl., 

 vio. (tyn. erecta). pur. Purple Wreath. 



Petalolepis (of Letting, are Petalacte). 

 Petasoitylis (see Leianthus). 



Other Species : 



macrostachya, 20', Je., st. and Stsipelia: is kept 



cl., HI. (HI/II. Stapelias). distinct. 



This is referred by Index rugosa, 6' to 8', Jy. , st., 



Kewensis to guiaiieusis, bl. 



PETROBIUM (syn- LAXMANNIA OP 

 FORSTKR). 



There is only one species (ord. Composite), and 

 it is an ornamental stove tree, increased by cuttings. 

 Soil, good, sandy loam. 



Only Species : 



arboreum, Je , st. tree, yel. 



PETROPHILA. 



Greenhouse shrubs (ord. Proteacea;). Very few 

 are in cultivation. The same culture as for Banksia 

 (which see) will suit. 



Principal Species : 



acicularis, 2', My., wh., red. 



Other Species : 



heterophylla, 4', Je., wh. rigida, 2' to 3', My., wh. 

 pulchella, 6 to8.Jy.,wh. Serruriu', 3' to 4', My., 



(*//. Protea puichella). wh. (//. glanduligera). 



PETTERIA. 



The only species, ramentacea (syn. Cytisus Wel- 

 denii, ord. Leguminosse) is a hardy shrub of erect 

 habit, requiring the same treatment as the hardy 

 Cytisuses. It is of little garden value. 



PETUNGA (syns. HIGGINSIA OP BLUME, 

 and SPICILLAHIA). 



Glabrous stove shrubs (ord. Rubiacece), of 

 branching, twiggy habit, and bearing white flowers. 

 Propagated by cuttings in April, in sand, over 

 bottom heat. Soil, fibrous peat and loam in. equal 

 parts, with one-fifth sand. 



Principal Species : 



Roxburghii, 3' to 8', My., flowers small, wh. 



PETUNIA. 



Description. Ornamental, half-hardy or hardy, 

 annual or perennial herbs (ord. Solanaceaj), largely 

 cultivated in pots and baskets, or used for bedding 

 plants. For the latter purpose, the small-flowered, 

 profuse-blooming varieties are best, the double 

 varieties and those with large single flowers 

 making handsome pot plants trained to a trellis 

 or wire frame. The cultivated Petunias are 

 derived from violacea and nyctaginiflora. Named 

 varieties are not now largely grown, but a selec- 

 tion appears on p. 181. 



Propagation. By seeds, which germinate freely 

 if sown in March in a hotbed, in light, fine soil, 

 and only slightly covered with earth, as the seeds 

 are very small. The seedlings ought to be pricked 

 off as soon as they can be handled. They are 

 afterwards potted off singly and pinched to make 

 bushy and compact plants, growing them on near 

 the glass in an intermediate temperature. Plants 

 to be grown in pots may receive their final shift in 

 May, when those for bedding should be hardened 



Pelroeal/is (sec Draba). 

 Petrocarya (see Parinarium). 

 Petrocoptis (see Lychnis). 

 Petrogeton (see Crassula). 

 Petroseliuum (see Parsley). 

 J'ettigree (see Jluscus arulcattts). 

 Pettlqrue (see llttxeux (U'ldcatus). 

 Pettyiehin (see tfcnista angltca). 



