Psidium 



( 243) 



Pteris 



- peudula, 50', pendu- 

 lous brauehes. 



- puiuilii, chvart' and com- 

 pact. 



- Stairii, Ivs. nearly wh. 

 in spr., uot so strong a 

 grower as the type. 



- Stautlishii, Ivs. larger 



than the type, silvery 



beneath. 

 taxifolia, Ivs. long and 



branches stout, dwarfer 



than the type, 

 maguirica (sen Abies mag- 



iiifica). 

 nobilis (sec Abies nobilis). 



PSIDIUM. (GUAVA.) 



A largo genus (pnl. Myrtacese) of stove trees, 

 shrubs, and sub-shrubs. Few of them are of any 

 garden value, and the genus is best known because 

 of the economic value of Guava, the delicious Guava 

 of the tropics. Cattleianum has been fruited under 

 glass in Britain with considerable success. Prop- 

 agation, by cuttings of the young shoots beginning 

 to get linn at the base, inserted in sand, under a 

 bell-glass, with bottom heat. Soil, fibrous loam 

 three-parts, leaf mould one part, and cow manure 

 one part, with one-eighth sand. Drainage must be 

 free, for the plants need a good deal of water, and 

 ;lo not like to be frequently disturbed. Large 

 wooden tubs will be required for fruiting plants, 

 or they may be planted out in a prepared border, 

 and the growths trained to a wall or trellis. 



Principal Species and Varieties : 

 cattleianum, 10' to 20', aroraaticuin, 5' to 8', 



My., wh., fruits claret Jy., wh., fruits yel. 



colour, reddish pulp, as pomiferum. Red Guava. 



large as a small Fig. pyriferum, Je., wh., 



There is a var. littorale. Pear shaped. Common 



(iu.iva, 6' to 15', Je., Guava. 



wh., fruits yel., globose, 



astringent (/. Guava). 



Other Species and Varieties : 

 aroniaticum (we Guava passeanum, 3' to 6', wh., 



var.). fruits gru. or yel., Pear 



cordatum (sec moutaiium) . shaped, 



inoiitanum, 5', My., Jy., polycarpon, 3', My., wh. 



\vh. (xi/n. cordatum). pyriferum (zee Guava 



Mountain (liiava. var.). 



PSILOTUM. 



Club-mosses (ord. Lycopodiacefe) of no great 

 horticultural value, although they are interesting. 

 Propagation, by cuttings. Triquetrum likes a well- 

 driiined pan of fibrous peat ; it will grow on stems 

 of dead Tree Ferns. 



Principal Species : 



triquctrum, 9", St., Ivs. very small or wanting, 

 stems forked. Mascarenica and nudum are vars. 



PSORALEA. 



A large genus (ord. Leguminosse) of hardy or 

 greenhouse, annual, biennial, or perennial herbs 

 and shrubs. Propagation, by cuttings of the half- 

 ripened shoots, in April and May, in sand, under a 

 bell-glass, for the shrubs ; by root division before 

 growth commences, for the herbaceous species. 

 Soil, light, rich loam for the hardy species, peat 

 for the pot plants. Although upwards of 100 

 species have been described, comparatively few of 

 them are in cultivation. 



Principal Species and Variety : 



acnleata, >' to 3', Jy., 

 grh. sin 1 ., bl., wh. 



]tiimat;t. :V to G', My., Jy., 

 grh. slir., hi. 



Other Species : 



aphylhi, 4' to"', sum., grh. 



shr., bl.,wh., Ivs. simple, 

 glandulosa, !', sum., hlf- 



iidy. slir., wh., bl. 



arborea, 6' to 8', My., 

 grh. shr., bl. (syn. 

 arborea). 



melilotoides, 1' to 2', 

 Aug., hdy. per., pale 

 pur. 



PSYCHOTRIA (syns. MTRSTIPHYLLUM 

 and PSYCHOTROPHUM). 



Stove shrubs, and erect and climbing herbs (ord. 

 Kubiacew). A few make good garden plants. 

 Propagation, by cuttings in spring, in sandy peat, 

 with brisk bottom heat. Soil, equal parts of loam 

 and peat, with one-sixth sand, and a few pieces of 

 charcoal. Free drainage. 



Principal Species : 

 cyauococca, bl., berries jasininiflora, shr., wh. 



bl., ripening in win., a (*//. Gloneria jasmiui- 



pretty herb, very useful flora). 



for win. decoration (./. sulphurea, cl., bl., fruits 



cyauocarpa). yel. 



Other Species: 

 leucocephala (see Eudgea racemosa, 2' to 3', Je., 



macrophylla). shr., wh., small, 



pilosa, herb, wh., fruits tabacifolia, Sep., shr., yel. 



bl. (*'/n. chontalensis). 



PSYLLA. 



A considerable number of species is included in 

 this genus of small insects (ord. Homoptera), and 

 they all bear a general resemblance to Aphides. 

 They are social in habits, and occasionally are 

 covered and protected by a cotton-like excretion. 

 They live by sucking the sap from the young 

 branches and leaves of plants, and sometimes these 

 wounds develop into galls. They differ from 

 Aphides by their greater size ; shorter, thicker 

 thighs, which enable them to make enormous 

 leaps ; harder bodies, and round wings. They do 

 not increase asexually. The two species which 

 most concern gardeners are pyrisuga, which does 

 considerable damage to Pears, and Mali, the Apple 

 Sucker. 



Although it is not difficult to kill the insects, it 

 is difficult to destroy the eggs without hurting the 

 trees. (i&e INSECTICIDES.) The persistent removal 

 of dead wood and snags should not be forgotten. 



PTELEA. 



Hardy trees (ord. Rntacetc). Propagation, by 

 seeds and layers. Garden soil. 



Principal Species and Variety : 

 trifoliata, 4' to 8', sum., aurea, foliage golden 



gru., yel. Hop Tree, when young, a pretty 



Swamp Dogwood. shrubbery plant. 



PTELIDIUM. 



A handsome stove shrub (ord. Celastrineas). 

 Propagation, by cuttings of ripe shoots, in sand. 

 Soil, loam and peat, with sand. 



Only Species : 



ovatum, 3', flowers grn., Ivs. very small. 



PTERIDOPHYLLUM. 



Herbaceous plants (ord. Papaveraceae), with 

 thick rhizomes. Allied to Hypecoum. Probably 

 not in cultivation. 



PTERIS. 



Description. This genus of Ferns (ord. Filices) 

 contains many useful and handsome garden plants. 

 Tremula, cretica, and serrulata, with their numerous 

 varieties, are grown by the thousand for market 

 purposes. The genus is remarkable for its wide 

 range hardy, greenhouse, and stove species are 

 included, and the length of the fronds varies from 



Psila (.ier Carrot Maggots). 

 1'tarmica (see Acliillea). 



