MICROSCOPIC STRUCTURE OF WEED SEEDS 



535 



sisting of an inner seed coat and a nucellus. The endosperm con- 

 sists of thin-walled parenchyma cells with granular contents con- 

 sisting of starch grains and protein. 



Fig. 412. Microscopic structure of some seeds of the Pink family (Cary- 



ophyllaceae). 

 I. Bouncing Bet (Saponaria officinalis) . II. Catchfly (Silene antirrhina). III. 



Virginia Catchfly (Silene virginica). 

 ep=epidermis. p=parenchyma» n=nucellus. h=hypoderm cells. en=endo- 



sperm. 

 (Drawings by L. H. Pammel.) 



The seeds of Virginia Catchfly (Silene virginica) are irregular. 

 The outer walls are greatly thickened, irregular, the underlying 

 parenchyma cells being slightly elongated. This, layer is followed 

 by the nucellus and the aleurone layer and remaining endosperm 

 cells containing starch grains and protein material. 



Silene inflata is described and figured by Harz*. 



*Samenkunde 2 :10-79. 



