Many plants are more useful than the Knot Grasses, it must be admitted, but without a brief reference to some few of the more attractive pecies this work would not be complete. The genus is a very large one) and contains hardy annuals, greenhouse evergreen shrubs, greenhouse herbaceous perennials, hardy herbaceous climbers, hardy herbaceous trailers, hardy herbaceous border plants, and hardy perennial rock plants. The first three sections are excluded from the present edition as being beyond our scope, while the best climbers and trailers will be found mentioned in our article on ClimbiNG. AND Trailing Plants, although a couple are described under rock garden species below. Left, then, with the perennial border and rock plants, we may point out that the first are plants of extremely easy culture, more suitable for the wild garden or shrub border than for the perennial parterre. Common garden soil and a sunny or lightly shaded spot are alone the essentials to success ; J and propagation, a matter of extreme ease, may be effected by seeds sown outside from March to July, or by division of the roots from October to March, any time between which months forms a suitable planting period. Perennial Border Species. We mention the following as being the most noteworthy of the numerous species : Polygonum alpinum.This and its varieties polymorphum and songaricum bear white flowers from June to July, and average 18-24 ins. in height. P. amplexicaule (S)m. P. petiolatum). This and its variety oxyphyllum produce red and white flowers respectively from mid-June onwards for six weeks, and average 1J-3 ft. in height. P. angustifolium.This nurserymans species has now been renamed P. Laxmanni. P. aviculare.This, the Common Knot Grass, is not worth growing.See Knot Grass in article on Weeds. P. baldschuanicum.See article on Climbhg and Trailing Plants. P. Bistorta.This is not worth growing save for medicinal purposes. See Bistort in our article on Medicinal Herbs. P. Convolvulus.This is a troublesome weedj and not worth growing. See Black Bindweed in article on Weeds. P. cuspidatum (Syn. P. Sieboldi). This plant, on account of its foliage, is specially useful for the wild garden. It bears white flowers from June to September, and grows 6-12 ft. high. P. divaricatum (Syn. P. salignum). This spreading species bears white flowers from July to August, and grows 1J-3 ft. high. P. Laxmanni (Syn. P. angustifolium). This is a well-known and useful white June blooming sort, about 12 ins. high. P. molle.This is a white sort blooming from June to August, and growing about i yd. high. A sort of this name is described by another authority as being synonymous with P. polysiachyurn, which see. P multiflorum. See article on Climbing and Trailing Plants. P. petiolatum.Syn. P. amplexicaule, which see. P. polystachyum. This is a white sort blooming from July to September, and averaging i yd. in height* P. sachalinense.This, on account of its very handsome foliage, is specially useful in the wild garden. It bears white flowers from June to September, and grows 4-12 ft. in height. P. salignum.Syn. P. divaricatum, which see. P. Sieboldi.Syn. P. cuspidatum, which see. h. virginianum.This is a useful Iwhite August blooming sort about I yd. in height. Rock Garden Species. Only three species of this large family are suitable for the rock garden. Two of these, P. affine and P. vaccinifolium, are valuable for covering large spaces. All are propagated by division of the roots in autumn or spring. Polygonum affine (Syn. P- Brunonis). This is a strong-growing creeper. Flowers rosy-pink. Site open. Soil sandy loam. Flowering Period, July to September. Height, 9 ins. P. sphaerostachyum (Syn. P. macrophyllum).This forms tufts of leathery leaves. Flowers bloodred in drooping spikes. Site shady . Soil boggy. Flowering Period, June. Height, 9 ins. P. vaccinifolium.This is a wellknown trailing plant. Flowers rosypink in spikes. Site open. Soil sandy loam. Flowering Period, July to October. Height, 9 ins.
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