2740 



POLYGONATUM 



POLYGONUM 



May-July. Moist woods, N. H. to Man., S. Ga., La. to 

 New Mex. and Utah. 



cc. Plant with Ivs. pubescent beneath. 

 bifldrum, Ell. Fig. 3101. Height 8 in. to 3 ft.: Ivs. 

 2-4 in. long, K~2 in. wide: fls. often 2 in axils, some- 

 times 1-4. April-July. Woods, New Bruns. to Mich., 

 south to Fla. Mn. 8:49. 



P. intermedium as offered in the European trade is presumably 

 P. intermedium, Dum., which is commonly considered nothing 

 more than a form of P. multiflorum, All. P. macrdnthum of foreign 

 trade-lists is botanically unknown. The plant offered in the 

 American trade as P. mdjus is not known botanically, but it is said 

 to grow 3 ft. high and bear pendent creamy fls. in May and June. 



WILHELM MILLER. 

 F. TRACY HUBBARD.! 



POLYGONELLA (diminutive of Polygonum). Poly- 

 gonacese. About 7 species of American plants closely 

 allied to Polygonum and of no horticultural standing, 

 although one or two names may appear in the trade. 

 P. polygama was offered in Mass, in 1881, but it is 

 probably not hardy N. The genus differs from Poly- 

 gonum in having only the inner sepals erect and the 

 calyx enlarged in fr., while in Polygonum all the sepals 

 are erect and the calyx is not enlarged in fr. 



polygama, Gray (P. parvifolia, Michx.). Diffuse 

 shrub: Ivs. wedge-shaped, vertical, those on sterile 

 shoots imbricated: racemes J^-1H in. long, very numer- 

 ous, in an oblong or corymbose panicle; fls. white, yel- 

 lowish or rose-color; filaments aU alike; stigmas nearly 

 sessile. Aug., Sept. Dry sandy soil, Fla. to N. C. 



americana, Small (P. ericoldes, Engelm. & Gray. 

 Gonopyrum americdnum, Fisch. <x Mey.). Perennial, 

 frutescent: Ivs. linear, persisting : racemes dense, diver- 

 gent; calyx white or pink; pedicels divergent, jointed 

 below the middle: achene elliptic-oblong, chestnut- 

 brown. Dry soil, Mo. to Texas, east to Ga. and Ala. 



POLYGONUM (Greek for many-jointed). Including 

 Persicdria, Bistorta, Tovdra. Polygondcese. JOINTWEED. 

 KNOTWEED. SMARTWEED. Erect or twining plants, 

 grown for ornament, the flowers and foliage often 

 attractive. 



Mostly herbs, annual or perennial, with small fls. on 

 jointed pedicels in racemes, spikes or heads (sometimes 

 solitary): Ivs. alternate, simple, jointed to an ocrea or 

 sheath which clasps or surrounds the st. and may at 

 length split and become indistinct: fls. apetalous; calyx 

 gamosepalous, 4-6-parted; stamens 3-9, sometimes 

 exserted; ovary 1-loculed, with 2-3-parted style or 

 stigma (latter capitate), ripening into a triangular or 

 lenticular achene. The species are per- 

 haps 200 (if the genus is held to include 

 Persicaria), of very wide distribution from 

 arctic to tropical countries, and they are 

 of widely different habit, from small 

 annuals, slender twiners, to subshrubs. and 

 ranging in habitat from dry open lands 

 to deep woods and watery swamps. The 

 calyx is corolla-like, often large 

 enough and with sufficient color 

 to render the infl. showy. Polyg- 

 onum is closely allied to Rumex, 

 the docks, and also to Fagopyrum, 

 the buckwheats. Rumex differs in 

 uniformly having a 6-parted calyx, 

 some of the lobes often bearing 



a grain-like tubercle on the back, the stigmas tufted. 

 Fagopyrum differs in having an achene surpassing the 

 calyx and in details of the embryo. Most polygonums 

 are weedy plants, and only a very small proportion are 

 of merit for cult. One of the commonest species is the 

 doorweed (Fig. 3102), Polygonum aviculare. It is a 



3102. Common doorweed or knotweed. Polygonum aviculare. 

 (XI; the details enlarged ) 



3103. Polygonum baldschuanicum. (.Spray X H) 



decumbent wiry small-lvd. annual or perennial, growing 

 along walks and in other hard dry soil, where it makes a 

 sod-like mat. The axillary fls. are very small, seldom 

 seen by others than botanists. Other polygonums are 

 the common smartweeds of swales and damp grounds. 

 For monograph of native and intro. species, see Small, 

 "Monograph of the North American species of the 

 genus Polygonum," in Mem. Dept. Bot. Columbia 

 College, 1895. 



Most of the cultivated polygonums are hardy border 

 plants, requiring no special skill or care. They are prop- 

 agated by seed and division, chiefly the latter. The 

 rhizomatous species, as those of the East Asian region, 

 produce readily divisible plants. Some of the cultiva- 

 ted kinds are annual, as P. orientale, and this species is 

 the only one that is known as a familiar flower-garden 

 plant, although it is now little grown and the seed is 

 difficult to secure in the trade. P. sachalinense is a 

 robust coarse plant of some value where screening foli- 

 age is desired and to occupy intractable ground ; it was 

 once extravagantly advertised as a forage plant. -P. 

 baldschuanicum is an attractive and worthy climber, 

 hardy in the northern states. P. Sieboldii is one of the 

 best of the species for the back or bold border and is 

 useful for forming single clumps when strong herbaceous 

 foliage effects are desired. The other species are em- 

 ployed mostly in wild gardening or for similar effects. 

 The amphibious kinds make interesting subjects for bog- 

 gardens. The pink or red often curved spikes of the 

 Persicaria group are sometimes very ornamental. The 



