Class VI. Order V. 87 



RUMEX BRITANNICA. L. Yellow rooted water Dock. 



Valves very entire, all of them grauiferous ; 

 leaves lanceolate with obsolete sheaths. 



A tall species growing in deep mud in watery situations, 

 Leaves broad-lanceolate, smooth and even. Stem furrowed, 

 surrounded above the joints with torn sheaths, a character which 

 distinguishes it from Rumex verticillatus, another aquatic spe- 

 cies with long tubular sheaths. Valves of the calyx large, 

 heart-shaped, entire, each bearing a grain. July. Perennial. 



RUMEX ACETOSELLA. L. Sorrel. Sheep's sorrel, 



Flowers dioecious, leaves lanceolate, hastate ; 

 calyx valves without grains. 



A common and unprofitable intruder into every species of 

 ground, but particularly such as are dry and sandy. The root 

 leaves furnish a good example of the halberd shape or hastate 

 form. Flowers in panicled racemes, small, with stamens and 

 styles on distinct plants. Valves ovate, entire, destitute of 

 grains. The acid properties of the plant are well knowo. 

 May. Perennial. 



POLYGYNLH. 



110. ALISMA. 

 AI.ISMA PLANTAGO. L. Water plantain. 



Leaves ovate, acute, capsules obtusely three 

 cornered. Sm. 



Common in small ponds and ditches. Leaves radical, peti- 

 oled, ovate, acute, smooth, nerved, entire. Panicle decompound, 

 its branches given off in whorls with bractes. Flowers with 

 three calyx leaves and three deciduous petals of a purplish 

 white. Capsules three cornered, obtuse. June, July. Peren- 

 nial , 



