THE RHUBARB FAMILY. 133 



Etherowe, were prisoners for the night, through losing their way. 

 " In the neighbourhood of Mottram." (B. G.) Fl. July, August. 



Curtis, iii. 489; E. B. xxviii. ]!)45. 



2. Small Wintekgreen — [Pyrola nimor.) 

 Chat Moss. (Mr. William Chambers.) Fl. July. 



Curtis, iv. 009 ; E. B. iii. 158 ; Baxter, iii. 239. 



XXII.— THE RHUBARB FAMILY. Polygonncece. 



Herbaceous plants, frequently of coarse and ungainly habit in stems 

 and foliage ; the flowers numerous, individually minute, but con- 

 spicuous in their large panicles or spikes. Leaves alternate, petiolate, 

 simple, often broad and large, with membranous stipules, which form 

 a thin semi-transparent sheath round the stalk, technically called an 

 ocrea, and, generally speaking, sufficient to stamp the family. Flowers 

 regular, consisting of calyx only, in five or six pieces, pink, white, or 

 greenish ; five, six, or eight stamens inserted on the base of the 

 perianth, and a solitary, one-seeded ovary, which is free, and sur- 

 mounted by two or more styles or stigmas, the latter in some cases 

 prettily tufted. Fruit usually a triangular or flattened nut. In the 

 sorrels the flowers are often unisexual. 



Few parts of the world are unacquainted with the Polygonacea. 

 In the northern hemisphere they occupy every meadow in the shape 

 of sorrels, and every ditch and piece of waste ground as coarse docks 

 and weedy persicarias, twining species of which latter creep into the 

 cornfields to spoil the grain. Sorrel on the one hand, and rhubarb 

 upon the other, may be taken as the representatives of their general 

 qualities. In both of these oxalic acid is copiously formed ; the stalks 

 of rhubarb also contain abundance of malic acid, giving them their 

 agreeable flavour when cooked. The roots ai;e universally nauseous. 



Twenty-nine species groAV wild in England, sixteen of them near 

 Manchester, referable to the two great sections or genera of docks and 

 persicarias. 



Sec. 1. The docks have a perianth of six divisions, three inner and 

 three outer, the interior segments large, and the stigmas tufted. The 

 stamens are uniformly six, and the flowers sometimes unisexual. 



Sec. 2. The persicarias have the perianth in five nearly equal divi- 

 sions, and the stigma undivided. Stamens five to eight. 



