Polygonatum.—Elegant liliaceous plants, with rhizomatous stems. P. multiflorum (Solomon’s Seal), 2 to 3 ft., with arching stems, and drooping white flowers from the leaf axils, is a handsome border plant, doing especially well in partial shade amongst shrubs, and also well adapted for pot culture for early forcing. Good garden soil.
Polygonum.—A large family, varying much in character, often weedy, but of easy culture in ordinary soil. P. vacciniifolium, 6 to 10 in., is a pretty prostrate subshrubby species, with handsome rose-pink flowers, suitable for rockwork, and prefers boggy soil; P. affine (Brunonis), 1 ft., deep rose, is a showy border plant, flowering in the late summer; P. cuspidatum, 8 to 10 ft., is a grand object for planting where a screen is desired, as it suckers abundantly, and its tall spotted stems and handsome cordate leaves have quite a noble appearance. Other fine species are P. baldschuanium, a climber, P. sphaerostachyum, P. lanigerum, P. polystachyum and P. sachalinense, all bold and handsome.
Potentilla.—The double varieties are fine garden plants obtained from P. argyrophylla atrosanguinea and P. nepalensis. The colours include golden-yellow, red, orange-yellow, crimson, maroon and intermediate shades. They all flourish in rich sandy soil.
Primula.—Beautiful and popular spring flowers, of which many forms are highly esteemed in most gardens. P. vulgaris, 6 in., affords numerous handsome single- and double-flowered varieties, with various-coloured flowers for the spring flower-beds and borders. Besides this, P. Sieboldii (cortusoides amoena), 1 ft., originally deep rose with white eye, but now including many varieties of colour, such as white, pink, lilac and purple; P. japonica, 1 to 2 ft., crimson-rose; P. denticulata, 1 ft., bright bluish-lilac, with its allies P. erosa and P. purpurea, all best grown in a cold frame; P. viscosa, 6 in., purple, and its white variety nivalis, with P. pedemontana and P. spectabilis, 6 in., both purple; and the charming little Indian P. rosea, 3 to 6 in., bright cherry-rose colour, are but a few of the many beautiful kinds in cultivation.
Pulmonaria.—Handsome dwarf, boraginaceous plants, requiring good deep garden soil. P. officinalis, 1 ft., has prettily mottled leaves and blue flowers; P. sibirica is similar in character, but has broader leaves more distinctly mottled with white.
Pyrethrum.—Composite plants of various character, but of easy culture. P. Parthenium eximium, 2 ft., is a handsome double white form of ornamental character for the mixed border; P. uliginosum, 5 to 6 ft., has fine large, white, radiate flowers in October; P. Tchihatchewii, a close-growing, dense evergreen, creeping species, with long-stalked, white flower-heads, is adapted for covering slopes in lieu of turf, and for rockwork.
Ramondia.—R. pyrenaica, 3 to 6 in., is a pretty dwarf plant, requiring a warm position on the rockwork and a moist, peaty soil more or less gritty; it has rosettes of ovate spreading root-leaves, and large purple, yellow-centred, rotate flowers, solitary, or two to three together, on naked stalks.
Ranunculus.—The florists’ ranunculus is a cultivated form of R. asiaticus (see [Ranunculus]). R. amplexicaulis, 1 ft., white; R. aconitifolius, 1 to 2 ft., white, with its double variety R. aconitifolius flore-pleno (Fair Maids of France); and R. acris flore-pleno (Bachelor’s Buttons), 2 ft., golden yellow, are pretty. Of dwarfer interesting plants there are R. alpestris, 4 in., white; R. gramineus, 6 to 10 in., yellow; R. parnassifolius, 6 in., white; and R. rutaefolius, 4 to 6 in., white with orange centre.
Rodgersia.—Handsome herbs of the saxifrage family. R. podophylla with large bronzy-green leaves cut into 5 large lobes, and tall branching spikes 3 to 4 ft. high—the whole plant resembling one of the large meadow sweets. R. aesculifolia, yellowish-white; R. Henrici, deep purple; R. pinnata, fleshy pink; and R. sambucifolia, white, are recently introduced species from China. They require rich sandy peat and warm sheltered spots.
Romneya.—R. Coulteri, a fine Californian plant, with large white flowers on shoots often as high as 7 ft.; R. trichocalyx is similar. Both require very warm, sunny spots and rich, sandy soil, and should not be disturbed often.