534 



WEED FLORA OF IOWA 



Fig. 411. Wild Four-o'clock (Oxybaphus nyctagineus) . The sclerotic paren- 

 chyma, parenchyma and epidermis belong to the pericarp. 

 ep=epidermis. p=parenchyma. scl=sclerotic parenchyma. t=testa. t 1 =tri- 

 chome. en=endosperm. r=ribs. 

 (Drawing by L. H. Pammel and Charlotte M. King.) 



consisting of an outer tangential layer with granular contents. 

 The aleurone layer and remaining portion of the endosperm cells 

 consist of large rather thin-walled cells with compound starch 

 grains and protein. 



Slender Catchfly (Silene antirrhina It.). 



The small kidney-shaped seeds are rough and brownish in color. 

 The outer epidermal walls are thick, brownish black in color. The 

 underlying parenchyma cells are tangentially elongated with near- 

 ly colorless walls. This is followed by an indefinite layer con- 



