AN ENCYCLOPAEDIA OF HORTICULTURE. 



185 



POLYOrONTJM (from polys, many, and gonu, a knee- 

 joint ; referring to the numerous joints of the stem). Knot 

 Grass or Weed. OBD. Polygonece. A very large genus 

 (nearly 150 species) of handsome, annual or perennial, 

 greenhouse or hardy herbs or (rarely) under-shrubs, of 

 variable habit, found throughout the world, but rare 

 within the tropics. Flowers usually fasciculate, some- 

 times so lax that they may be regarded as axillary; 

 perianth funnel-shaped or campanulate, usually coloured, 

 with five somewhat unequal segments; pedicels articu- 

 lated above or below the middle. Leaves alternate, with 

 ochreate stipules. A great number of the species, twelve 



Polygonum continued. 



P. amplexicaule (stem-claspingX* . bright rose-red or white, 

 in solitary or twin racemes 2in. to 6m. long. September 

 and October. L cordate-ovate or cordate-lanceolate, long- 

 acuminate, the lower long-petipled, the upper sessile and 

 amplexicauL Stems 2ft to 3ft high, from a strong, woody root- 

 stock. Himalayas. Hardy perennial herb. (B. M. 6500.) 



P. Bistorta. Bistort or Snakeweed. fl. reddish-pink, in a dense, 

 terminal, erect, solitary spike. June to September. L chiefly 

 radical, large, oblong or ovate-obtuse, glaucous beneath, on long 

 petioles. A. lift Europe (Britain), North and West Asia. 

 Perennial herb. (Sy. En. B. 1243.) 



P. Brnnonis (Brown's). A synonym of P. affine. 



P. capitatnm (headed), fl. pink, small, growing in dense, round 

 heads, on long stalks, from the upper leaf mril^ J. ovate or 

 elliptical, 2m. long, green, marked with dark V-shaped bands, 

 extending from the midrib at the centre to the base of the leaf. 

 Stems slender, diffuse, hairy, rooting. North India. A pretty 

 little, cool greenhouse or half-hardy, perennial herb, with a neat, 

 spreading habit (Bet B. 1L) 



P. cbinense 

 green, others pu 

 the in 



inside with 

 China to India, Ac. 



foliis-pictts (painted-leaved Chinese). L, so 

 purple, and all with a V-shaped mark, margined 

 th a dark line of deep purple or blackish-gree 



deep purple or blackish-green. 

 Hardy perennial herb. (B. M. 5238.) 



Septem- 



FIG. 227. POLYGONUM ORIENTALS, showing Habit, detached 

 Spike, and Single Flower. 



of which are British, are of no ornamental value what- 

 ever, but the following are desirable and worth growing. 

 They are of the easiest possible culture in any ordinary 

 garden soil, but they well repay generous treatment and 

 a good position. P. cuspidatvm and P. sachalinense 

 are specially noteworthy and fine amongst hardy plants 

 where space is allowed them to develop. The uTiTinala 

 are raised from seeds, sown in the open border, in spring, 

 or raised in heat, and after- 

 wards planted out. This latter 

 plan is the best with such 

 species as P. orientate, which, 

 in a warm, sunny spot, in good, 

 rich soil, forms a very fine 

 plant. The perennials are in- 

 creased by dividing the root- 

 stocks. 



P. compactnm (compact).* fl. white, in erect racemes. 

 ber. 1 somewhat crimped, h. 2ft. Japan, before 1875. This 

 is probably a variety of P. eufpidtitum ; but it is very distinct in 

 the way implied by its name, being more compact and rigid, and 

 not more than half so talL The leaves, too, are of a much darker 

 colour. Its habit is, however, less graceful than that of P. au- 

 pidatum. Hardy perennial herb. (B. M. 6476.) 



P. enspidatnm (pointed-leaved).* fl. creamy- white, forming 

 drooping, feathery panicles, 4in. to -Sin. long, succeeded by scarlet 

 fruits. Summer. L large, somewhat distichous, oval-oblong, 

 cuspidate, petiolate. h. 4ft. to 8ft. Japan, 1825. A hardy 

 perennial herb, of quick growth, and having Ion;:, slender stems. 

 It is best grown as an isolated specimen. See Fig. 226. (B. M. 

 6503; L. A P. F. G. i., p. 137 ; B. G. 291.) SY>. P. Sieboldii (ot 

 gardens). 



P. filiforme variegatum (thread-like, variegated).* L large, 

 drooping, oval-oblong, finely splashed or marbled with pale green 

 and yellow. Japan, 1865. A hardy perennial, fine for sub- 

 tropical gardening. 



P. orientate (Eastern).* fl. deep rosy-purple or white, in long, 

 drooping racemes, which are both terminal and axillary. August. 

 L large, ovate-acuminate, pilose or nearly glabrous, h. 3ft to 

 4ft, or sometimes nearly 10ft East Indies, 1707. A large and 

 free-growing, hardy annual, with very robust stems, which give 

 off n!unero5s, lateral shoots. See Fig. 227. (B. M. 213.) 



P. sachalinense (Sachalm).* fl. of a delicate greenish-yellow 

 colour, in axillary racemes; bracts ovate, long-pointed. Late 

 L broadly ovate or ovate-oblong, acuminate, the lower 



(kindred).* fl. rosy-red, 

 spikes, freely produced 



in dense . 



throughout the autumn. I. few 

 and narrow, h. 6in. to 8in. 

 Nepaul, 1822. A very orna- 

 mental, hardy perennial. (B. M. 

 6472.) SYN. P. Bmnonit (L. J. F. 

 117 ; L. & P. F. G. 37). 



P. alptnnm (alpine), fl. snow- 

 white, panicled. Summer. L 

 ovate-lanceolate, deep green, with 

 ciliated margins, h. 3ft. to 4ft 

 Alps, 1816. This very desirable 

 perennial is particularly useful 

 where cut flowers are much in 

 request 



P. ampnibium (amphibious). 

 Willow Grass. A. bright red, 

 in dense, ovate spikes. July. 

 I. lanceolate. Stem round, leafy. 

 North temperate and Arctic 

 regions (Britain). An aquatic 

 or semi-aquatic perennial herb. 

 When growing in water, the 

 petioles are very long and the 

 stipules smooth ; whilst the ter- 

 restrial form has short petioles and 

 hispid stipules. (Sy. En. B. 124a) 



VoL HI. 



FIG. 228. POLYGONUM SACHALINENSK. 



2B 



