MICROSCOPIC STRUCTURE OF WEED SEEDS 



559 



Measurements, seed coats, 122m ; outer integument, 27m ; outer 

 layer of same, 22m ; inner layer of same, 5m ; palisade layer, 70m ; 

 subpalisade, 25m. (P. H. Rolfs.) 



OOE3Q^ 



T 



QSOCb 



Fig. 426. Microscopic structure of the seeds of some Malvaceous weeds. 

 I. Shoo-fly (.Hibiscus trionum). II. Indian Mallow or Butterprint (Abutilon 



theophrasti) . III. Mallow (Malva sylvestris). IV. Sida (Sida spinosa). 



V. Cheeses or common Mallow (.Malva rotundifolia) . 

 ep=epidermal cells. m=malpighian cells. ll=light line. pi=pigment layer. p= 



parenchyma cells. pal=palisade or malpighian cells. n=nucellus. en=en- 



dosperm. h=trichome. t=plant hair or trichome surface view 

 (Drawings hy P. H. Rolfs.) 



Cheeses or Mallow {Malva rotundifolia L.). 



The roughened, somewhat velvety, dark grayish seeds consist 

 of an outer row of rather large, rather thick-walled cells, walls 

 colorless. This layer is followed by the very long Malpighian 

 cells, which are longer than the cells of the rest of the testa, light 

 line near the upper part of the cell, lower portion of cell slightly 

 yellowish. Cavity spindle-shaped near the middle. The dark 



