36 



characteristics is likely to be confounded with the true pigweeds, 

 which, however, are Amaranthus, and not Chenopodium. 



The seed as found is double convex in shape, and its diameter 

 laterally varies between .75 — 1.5 m.m. In color it is black and 



d 



Figure 29 

 Fig. 29. Lambs-Quarters. 



shiny. Very often the seed is found encased in the hull or cover 

 in which it grows. It is then gray in color and of the same gen- 

 eral shape as the seed itself. By rubbing between the fingers 

 the covering may be removed and the shiny black seed exposed. 

 The outer seedcoats when cleared and examined under the mi- 

 croscope are seen to be made up of large, roughly rectangular 

 irregular cells which vary in diameter from 25 — 75ai and which 

 are covered with minute rough projections similar to those of 

 rough pigs\'eed. The size and rectangular shape of the cells 

 distinguish this seed from species of Amaranthus. 



LADIES' THUMB, SMARTWEED. 



{Polygonum Persicaria, L.) 

 This seed is often found in feeds and more especially in chick 

 feeds, and is much like a flattened buckwheat seed having two 



Figure 30 

 Fig. 30, Ladies' Thumb. 



faces instead of three; it is from 1 — 2 m.m. in length and .75 — 

 1 m.m. broad, and dark glossy brown to black in color, and very 

 smooth. 



