SPERMATOPHYTA— POLYGONACEAE 419 



as that found in rhubarb, and rheotannic acid. The patience dock R. Patien- 

 tia), pale dock (R. altissimus) and curled dock (R. crispus) are troublesome 

 weeds; French sorrel (_R. scutatus) is cultivated in Europe and used as a salad. 

 The presence of the silver plant of the west (Briogonum umbeltatum) is said 

 to be indicative of gold and silver. Muehlenbeckia platyclados of the Samoan 

 Islands is frequently cultivated in greenhouses. The mountain sorrel {Oxyria 

 digyna) is used as a salad plant. 



Genera of Polygonaceae 



Sepals 6; stigmas 3 ■. 2 Rumex. 



Sepals S, occasionally 4, erect in part. 

 Achenes triangular or lenticular. 



Embryo slender curved around one side of the endosperm 3 Polygonum. 



Broad cotyledons of embryo twisted and plaited 1 Fagopyrum. 



1. Fagopyrum (Tourn.) L. Buckwheat 



Annual or perennial; somewhat fleshy, smooth, leafy herbs with erect 

 stems; leaves petioled and alternate; hastate or deltoid flowers, small, white, 

 or greenish, paniculately-racemose, perfect; calyx S-parted, persistent, the divi- 

 sions like petals; stamen 8; ovary 1-celled, 1 ovule, style with 3 divisions; 

 fruit an achene, 3-angled ; endosperm mealy ; cotyledons broad. About 6 species 

 native to the old world. 



Pagopyrum esculentum Moench. Buckwheat 



Smoothish plants; leaves hastate, abruptly narrowed above the middle; 

 sheath half-cylindrical; racemes somewhat panicled, many flowered; sepals 

 white, fragrant, with 8 honey-bearing yellow glands situated between the stamens. 



Distribution. A common escape in eastern North America. Native of 

 Eastern Europe and Western Asia. 



Fagopyrum tataricum (L.) Gaertn. India-wheat 



Annual, similar to the above species; leaves deltoid, hastate ;flowers smaller; 

 pedicel short. 



Distribution. In waste places from eastern Canada to New England. Na- 

 tive to Asia. 



Poisonous properties. Fagopyrum contains the glucoside indican C^gHj^NOu 

 found also in Nerium and other plants. The plant produces bloat especially 

 if consumed before bloom. 



Several years ago the writer received a complaint from a farmer stating 

 that the feeding of buckwheat had produced a ra.>!h upon his hogs. Feeding of 

 buckwheat and the eruptions or urticaria following are well known to veter- 

 inarians. 



Dr. Millspaugh says of buckwheat : 



Many individuals cannot partake of pancakes made frcn the flour of the seeds without 

 experiencing a severe itching especially observed about the large joints. A peculiarity of 

 this itching is that it occurs after the removing of the nothing and when first retiring 

 at night. The eruption incident to and following this itcl-'ng takes the form of vesicles 

 which degenerate into dry, dark colored scabs. Another symptom arising is a glutinous 

 condition of otherwise natural feces, making expulsion qu'*e difficult. Increased urinary 

 discbarge is also present in many cases. 



