An Encyclopedia of Horticulture. 



186 



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

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

 Grass or Weed. Ord. Poli/fjonea'. A very large g-enns 

 (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 campanulato, usually coloured, 

 with five somewhat unequal segments; pedicels articu- 

 lated above or below the middle. Leaves alternate, with 

 ochreate stipules. A groat number of the species, twelve 



Fig. 227. Polygonum orientale, 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. cunpidatum and P. aachalinense 

 are specially noteworthy and fine amongst hardy plants 

 where space is allowed them to develop. The annuals 

 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. orientale, 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. afflne (kindred).* Jl. rosy-red, 

 in dense spikes, freely produced 

 thronghout the autumn. ;. few 

 and narrow. h. 6in. to Sin. 

 Nepaul, 1822. A very (irna- 

 mental, hardy perennial. (B. M. 

 6472.) SYN. P. lirunonisCL. J. F. 

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



P. alplnnin (alpine). /. snow- 

 white, piinicleil. Slimmer. I. 

 ovate-lanceuhite, 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. amphlbiuxn (amphibious). 

 Willow Gniss. d. bright red, 

 in dense, ovate spikes. July. 

 I. lanceolate. Stem round, leafy. 

 North temperate and Arctic 

 regions (Uritain). An aquatic 

 or serai-aquatic perennial herb. 

 When growing in water, the 

 petioles are very Inng and the 

 stipules smooth ; whilst the ter- 

 restrial form has short petioles and 

 hispid stipules. (Sy. En. B. 1242.) 



Vol. III. 



Polyg-ouum — continued. 



P. amplexicaule (stem -clasping;).* /. bright rose-red or white, 

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

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

 acuminate, the lower long-petioled, 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. /. reddish-pink, in a dense, 

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

 railical, large, oblong or ovate-obtuse, glaucous lieneath, on long 

 pe.tiules. h. l^ft. Europe (Britain), North and West Asia. 

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



P. Briinonis (Brown's). A synonym of P. ajfine. 



P. capitatum (headed). Jl. pink, small, gi-owing in dense, round 

 heads, on long stalks, from the upper leaf axils, l. uvate or 

 elliptical, 2in. long, ^een, markecf 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-hartly, perennial herb, with a neat, 

 spreading habit. (Ref. B. 11.) 



P. chlnense folils-plctis (painted-leaved Chinese), l, some 

 green, others purple, and all with a V-shaped mark, margined on 

 the inside with a dark line nf deep purple or blackish-green. 

 China to India, &c. Hardy perennial herb. (B. M. 5238.) 



P. compactum (compact).* ji. white, in erect racemes. Septem- 

 l>er. I. somewhat crimped, h. 2ft. Japan, liefore 1875. This 

 is proliably a variety of P. cuspidatuin ; but it is very distinct in 

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

 not mcn-e than half so tall. The leaves, too, are of a much darker 

 colour. Its habit is, however, less graceful than that of /*. cus- 

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



P, cuspldatum (pointed-leaved).* /I. creamy-white, forming 

 drooping, feathery panicles, 4in. to 5in. long, succeeded by scarlet 

 fruits. Sunnner. I. large, somewhat distichous, oval-oldong, 

 cuspidate, petiolate. h. 4ft. to 8ft. J:ipan, 1825. A hardy 

 perennial herb, of quick growth, antl having lon^, slender stems. 

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

 6503; L. & P. F. G. i., p. 137 ; R. G. 291.) Syn. P. Sicboldii {of 

 gardens). 



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

 droojiing, ov:d-oblung, finely splashed ur marbletl with pale green 

 and yellow. Jai)an, 1865. A hardy perennial, fine for sub- 

 tropical gardening. 



P. orientale (Eastern).* Jl. deep rosy-purple or white, in long, 

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

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

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

 free-gi"owing, hardy annual, with very robust stems, which give 

 off numerous, lateral shoots. See Fig. 227. (B. M. 213.) 



P. sachalinense (Sachalin).* ji. of a delicate greenish-yellow 

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

 summer. I. broadly ovate or ovate-oblong, acuminate, the lower 



Fig. 228. Polygonum s.\chalinense. 



2b 



