An Encyclopedia of Horticulture, 



211 



Potato Beetle — continued. 

 locality, at a distance from other habitats, as mast be 

 the case in their appearance anywhere in Europe. 



For other Beetles destructive to Potatoes, see remarks 

 on Insects under Potato. 



POTATO ONIOIT. A variety of Onion, cultivated 

 in much the same way as Shallots. Single bulbs may 

 be planted in January, or as early in spring as weatlier 

 permits, in rows about 12in. apart, a distance of 6in. 

 being allowed in the rows. The produce is useful for 

 an early supply. Increased only by tubers. 



POTATO. SPANISH or SWEET. A common 

 name applied to Batatas edulis (which see). 



POTENTILLA (a kind of diminutive from potens, 

 powerful ; alluding to the reputed medicinal 

 power, of which these plants really possess very 

 little, being merely mild astringents, like the 

 rest of the tribe). Cinquefoil. Including Com- 

 arum, Horkelia, Sibbaldia^ and Tonnentilla. 

 Ord. Rosare(e. A large genus of glabrous, 

 pilose, or silky-tomentose, mostly hardy sub- 

 shrubs or herbs, rarely annuals. According to 

 the authors of the " Genera Plantarum," the 

 species number about 120, although upwards 

 of 220 have been accorded specific rank 

 by various authors. They are natives of the 

 temperate and frigid regions of the Northern 

 hemisphere, rarely occurring in the tropics ; 

 only two species have been found in the 

 Southern hemisphere. Flowers white or 

 yellow, very rarely red or purple, often 

 disposed in corymbose cymes, rarely axillary 

 and solitary : calyx persistent, with a concave, 

 hemispherical, or urceolate tube, and five (rarely 

 four) erect or spreading, triangular-ovate, val- 

 vate lobes ; petals five (rarely four), obovate, 

 orbiculate, or linear-spathulate : stamens usually 

 numerous. Leaves alternate, or the floral ones 

 opposite, digitately three to seven-foliolate or 

 imparl - pinnate ; leaflets solitary, or bi- or 

 ternate, often lobed or divided ; stipules adnate 

 to the base of the petioles. Several species 

 of this genus are very desirable subjects for 

 rockwork, bare banks, and similar situations ; 

 they thrive in almo-st any moderately good 

 garden soU, but a sandy one is preferable. 

 PotentiUas may be readily propagated by divi- 

 sion, or by seeds. Some of the hybrid forms 

 are of far more importance to horticulturists 

 than the typical species. The undermentioned are hardy 

 herbaceous perennials, except where otherwise specified. 



P. alba (white). /. white, with a dark orange ring at the ha.se, 

 nearly lin. across ; petals obcordate, longer than the calyx ; 

 pedicels axillary ana terminal. February to August. I., lower 

 ones quinate, upper ones ternate. Stems procumbent, weak. 

 European Alps, &c. 



P. alpestrls (mountain). Jl. bright yellow, about lin. across, 

 with cordate petals and acute sepals; pedicels axillary 

 and terminal, long. July, l.y radical ones of five, rarely of 

 seven, wedge-shaped, rather hairy leaiiets, deeply cut in the 

 upper half. Stems ascending. /(. 6in. to 12in. Europe, &c. 

 (Britain). (Sy, En. B. 429.) 



P. ambigua (doubtful).* jl. rich yellow, about lin. across, and 

 just overtopping the dense carpet of foliage. June. I. green, 

 fonuing a dwarf, dense mass. h. bin. Himalaya, 1851. A creeping 

 plant, of free growth. (B. M. 4615.) 



P. arguta (sharply-serrated). Ji. pale yellow, in a crowded, dichoto- 

 mous panicle; petiils obovate, entire, longer than the calyx. 

 June and July. I. pinnate ; leaflets roundish-ovate, oblique at 

 base, doubly and deeply toothed. Stem erect, pubescent, h. lit. 

 to 3ft. North America, 1826. (B. R. 1379.) 



P. argyrophylla (silvery-leaved).* Jl. yellow, jin. to l|in. in 

 ■ liann-ter ; pet.als olicordate-cuneate ; calyx silky. Summer. /., 

 Ifatiets sessile or slightly stalked, green, finely silky above, white 

 beneath ; teeth acute. A. lift, to 3ft. Himalaya. S\y. P. iimquis 

 (B. R. 1841, 37). 



P. a. atrosangninea (dark blood-coloured). Jl. of a beautiful 

 dark crimson. Himalaya, 1822. Sy.\. P. atrosaiiquinea (L. B, C. 

 786 ; B. M. 2689). 



Poteutilla — eontinued. 



P. atrosangulnea (dark red). A synonym of P. argyrophylla 

 atroxanfiuiiica. 



P. Clusiana (Clusins'). jl. in terminal corymbs ; corolla white, 

 large ; petals roundish, hardly longer than the calyx. June to 

 August. I., radical ones quinate, cauline ones ternate ; leaflets 

 ovfd-cuneiforni, pubescent, tridentate at apex, with coimivent 

 teeth, h. 6in. Eastern Piurope, Ac, 1806. (B. M. 1327 ; 

 J. F. A. 116.) 



P. Comarum (Comarum). Marsh Cinquefoil or Potentil. This 

 is the correct name of the plant described in this work as 

 Cijinanun palw^tic 



P, congesta (crowded).* Jl. crowded, terminal ; corolla white > 

 petals longer than the calyx ; outer calyx segments quite entire- 

 August. (., radical ones pinnate ; leaflets eimeate-oblong, cut at 

 the apex. Ii. 1ft. to 2ft. California, 1826. (B. M. 2880, under 

 name of Horlcclia coufiesta.) 



P. formosa (beautiful). A synonym of P. mpalciusis. 





FlG. 265. POTENTILLA FRUTICOSA, showing Flowering Branch, detached 

 Flower, with Petals removed, and Carpel. 



P. fruticosa (shrubby).* Jl. yellow, sub-corymbose, numerous, 

 small, with obovate-roundish petals, longer than the calyx. 

 Summer. I. pinnate; leaflets oiilong-lanceolate, ciuite entire, hairy. 

 h. 2ft. to 4ft. Northern hemisphere (Britain). Shrub. See 

 Fig. 265. (Sy. En. B. 436.) 



P. gracilis (slender). /, golden-yellow ; petals obcordate, longer 

 than the silky calyx. July. I. quinate, lower ones on long 

 petioles, upper ones sessile ; leaflets lanceolate, deeply and pin- 

 natifiiily serrated, white-tomentose beneath. Stem hairy, 

 corynil)osely panicled at apex. h. 1ft. to 2ft. North America, 

 1826. (B. M. 2984.) 



P. grandiflora (large-flowered). Jl. yellow, large ; petals 

 obcordate, twice the length of the caly.x ; receptacle pilose. 

 June and July. I. ternate ; leaflets obovate, cuneate at base, 

 deeply serrated, pilose. South F^urope, 1640. Plant ascending. 

 (B. M. 75.) 



P. Hopwoodiana (Hopwood's).* yi., petals beautifully variegated, 

 marked with a spot of detp rose-colour at the base, and from it 

 to the centre of a pale stiaw-colour, edged with bright rose- 

 colour. June and July. I., lower ones with five or six leaflets, 

 upper ones ternate ; leaflets oblong-cuneiform, coarsely toothed, 

 hairy on both surfaces. A. IJft. A hybrid. (B. R. 1387 ; 

 S. B. F. G. ser- ii 61.) 



P. insignls (remarkable). A synonym of /'. anjyrophylla. 



P. laclniosa (jagged-leaved), jl. yellow, disposed in coiymbuse 

 panicles; ptt.-i'ls irbcord:ite, much longer than ihe calyx. June 

 and July. (. with five to seven oblong, laciniately-pinnatifid, 

 pilose leaflets. Stem erect, reddish, h. 1ft. to Uft. Hungary, 

 1816. A .sub-.species of P. rccla. (B. R. 1478.) 



P. luplnoldes (Lupine-like). A synonym of P. nivalis. 



