SPERMATOPHYTA POLYGONACEAE 419 



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

 lia), 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 (Eriogonum umbellatum) is said 

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

 Islands is frequently cultivated in greenhouses. The mountain sorrel (Oxyrla 

 digyna) is used as a salad plant. 



Genera of Polygonaceac 



Sepals 6 ; stigmas 3 2 Rumex. 



Sepals 5, 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 5-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. 



Fagopyrum 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, 6 H 31 NO 17 

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

 if consumed before bloom. 



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

 that the feeding of buckwheat had produced a rash 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 fro*n 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 rlothing and when first retiring 

 at night. The eruption incident to and following this itc'^'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 

 discharge is also present in many cases. 



