AN ENCYCLOPAEDIA OF HORTICULTURE. 



71 



Pentas continued. 



under a propagating glass, in gentle heat. The plants 

 should be occasionally pinched as they grow, to en- 

 courage a more compact habit. 



P. carnea (flesh-coloured)." fl. disposed in numerous, large, 

 cymose heads. Winter, and almost all the year round. I. soft, 

 opposite, bright green. h. lift. South Africa, 1842. A hand- 

 some, compact-growing, soft-wooded sub-shrub. See Fig. 75. 

 (B. M. 4086 ; B. R. 1844, 32.) 



P. c. kermesina (carmine).* A showy plant, differing from the 

 type chiefly in having flowers of a lively carmine-rose, tinted 

 with violet in the throat. (R. H. 1870, 130.) 



P. parviflora (small-flowered). fl. flame-colour; corolla tube 

 twice or thrice as long as the calyx. April. I. ovate or oval- 

 oblong, acuminate, narrowed at base, scarcely pubernlous on the 

 veins, h. 2ft. Western tropical Africa, 1846. Sub-shrub. 



PENTATAXIS. Included under Helichrygum. 



PENTLANDIA. Included under Urceolina 

 (which see). 



PENTSTEMON (from pente, five, and stemon, a 

 stamen; the fifth stamen being present and conspicuous, 

 although sterile). Beard-tongue. STN. Penstemon. OBD. 

 Scrophularinece. A genus comprising about sixty-six 

 species of very ornamental, mostly hardy, perennial herbs 

 or sub-shrubs, natives of (mostly Western) North America, 

 including Mexico. Flowers red, -violet, blue, white, or 

 rarely yellowish-white, showy; calyx of five imbricated 

 segments ; corolla tube usually elongated, equal or ventri- 

 cose; limb bilabiate, the upper lip two-lobed, and the 

 lower three-cleft, bearded or naked; stamens four, didy- 

 namous, shorter than the corolla, the staminode filiform, 

 with a clavate or spathulate tip, generally much shorter 

 than the stamens; peduncles dichotomously many- flowered, 

 bracteate at the ramifications and disposed in a terminal 

 panicle or thyrse, which is often leafy at base, rarely one- 

 flowered, and disposed in a simple raceme. Leaves 

 opposite, the radical and lower ones petioled, gra- 

 duating into amplexicaul floral ones, or decreasing into 

 bracts. Flowering branches often erect, simple, rarely 

 diffusely branched. Amongst popular hardy plants, few 

 surpass Pentstemons for their usefulness and ornamental 

 character in the mixed border or rock - garden, or for 

 planting in beds by themselves. Their flowering season 

 commences about June, and continues until after the 

 appearance of frost, in autumn. Many of the species 

 are very attractive, and are indispensable in the 

 choicest collection of herbaceous plants; and a selection 

 from the numerous varieties, improved so much of late 

 years, is equally valuable for garden decoration and for cut 

 flowers. 



Pentstemons are very varied in colour, and possess 

 a naturally graceful and exceedingly floriferous habit. 

 They may readily be propagated from seeds, and also 

 from cuttings; the latter method being most generally 

 adopted for perpetuating species and named varieties. 

 Seeds may, however, sometimes be obtained, in favour- 

 able seasons, from plants that do not readily produce cut- 

 tings ; under such circumstances, it is most important to 

 collect them, if required for increasing stock. If pre- 

 served from named varieties, with a view to raising new 

 ones, only such as have finely -formed flowers and dis- 

 tinct colours should be selected for seed-bearing. Seeds 

 should be sown in pans or shallow boxes of light 

 Boil, about February, or early in March, and placed 

 on a gentle hotbed. So soon as the seedlings are 

 large enough to handle, they should be potted off singly, 

 or pricked into boxes, and kept in a little warmth 

 until established, when they may be gradually hardened 

 and placed in a cold frame. Towards the end of May, 

 plant them in a prepared border outside, where, if pro- 

 perly attended to, many will flower in the ensuing autumn. 

 Seeds may also be sown, in the open ground, early in 

 June, when- the plants should be potted up in August, 

 and preserved in cold frames through the winter, for 

 flowering early the following year, after being again 



Pentstemon continued. 



transferred to the outside. Cuttings root readily at 

 almost any season when they are procurable. The best 

 time to take them is in August and September, from the 

 numerous side-growths that are usually plentiful at that 

 season. They may be inserted in cutting-pots or pans, 

 and placed in a close frame without artificial heat, or, 

 failing this, under a hand glass, in a sheltered position,' 

 where coverings may be readily applied, if necessary, 

 afterwards. For the winter, the plants succeed best in 

 a cold frame ; they may be put into permanent quarters 

 again, outside, during April, or earlier, should the 

 weather be favourable. It is important, first, to expose 

 them for a few days, in order to thoroughly harden 

 them, and avoid an undue check. 



Although Pentstemons are hardy, they frequently 

 succumb when subjected successively to wet and frost, 

 the first-named being, perhaps, the more destructive of 

 the two. It is important, therefore, to provide good drain- 

 age, particularly for any of the more select species or 

 varieties. A sandy loam, enriched with leaf mould or 

 decayed manure, should be the compost prepared, if 

 necessary, or these ingredients may be added to fairly 

 good soil in borders for enriching it. Pentstemons well 

 repay for liberal treatment and a rich soil. They re- 

 quire plenty of water throughout the summer ; it is in 

 winter when they suffer from being too wet. The best 

 plan is to insert cuttings annually, and preserve a stock 

 in a cold frame. If any old plants are to kept outside, 

 they should be covered, in autumn, with ashes. 



The species and varieties best known to gardeners are 

 described below ; except where otherwise indicated, they 

 are hardy, herbaceous perennials. 



P. acnmlnatns (taper-pointed), fl. lilac, or changing to violet ; 

 corolla tube scarcely enlarged above ; sterile filament bearded 



above ; panicle strict, interrupted ; cyme 



L entire ; radical ones petioled, oblong or ovate, obtuse, mu- 



cronulate ; upper 



P. angustifolius (narrow-leaved). 



ile, crowded. July. 

 or ovate, obtuse, mu- 

 r ones connate, clasping. Stem erect, 1ft. high. 



A synonym of P. eampanu- 



Fio. 76. PE.VTSTEMO> BARBATUS, showing Habit and portion of 

 detached Inflorescence. 



P. antirrhlnoldes (Snnpdragon-like).* ,/f. lemon-yellow; corolla 

 ventricose, naked, with large lips; sterile filament densely 

 bearded on one side ; peduncles two-leaved, often one-flowered. 

 Summer. L spathulate-lanceolate or oval, sub-petiolate, rather 

 small, entire, A. 9in. to ISin. 1824. Plant sub-cinereous, much- 

 branched. (B. M. 6157.) 



P. atropurpureus (dark purple). A synonym of P. eampanu- 

 lotus. 



P. attenuatos (attenuated) fl, yellowish-white or bluish-purple, 



lla 

 viscous-pubescent 



variable ; corolla more than iin. long ; inflorescence villous or 

 viscous-pubescent July. J. very glabrous, nearly always entire, 

 rarely slightly denticulate; caullne ones lanceolate or oblong. 

 A. IJft. to 2ft. 1827. (B. R. 1295.) 



P. aznrena (azure-blue).* fl., corolla of a beautiful azure-blue, 

 reddish-purple at the base of the tube, more than Iin, long ; 



