MICROSCOPIC STRUCTURE OP WEED SEEDS 



533 



embryo are somewhat elongated ; the remainder are nearly as broad 

 as long; these contain no starch but albuminoids and fat. 



Fig. 410. Microscopic structure of seeds of the Chenopod family. CChenopodia- 

 ceae). I. Russian Thistle (.Salsola kali va,T, tenuifoUa). II. Lamh's Quar- 

 ters (.Chenopodium, album'). 



ep=epidermis. p=parenchyma cells. t=testa. n=nucellus. en=endospenn. 

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



NYCTAGINACEAE, FOUR-O'CLOCK FAMILY. 



Wild Four-o'clock or Umbrella Plant {Oxybaphus nyctagineus 



(Mx.) Sweet). 



The nutlike fruit of the wild four-o'clock or umbrella plant is 

 somewhat hairy; the outer portion of the pericarp is made up of 

 thick black-brownish cells from 6 to 9 rows. The epidermal cells 

 are smaller, some of the eeUs elongated into one-ceUed thick- walled 

 trichomes. Adjacent to the testa are bundles of thick-walled, 

 sclerotic cells, the outer layer of cells of the testa consisting of 

 mucilaginous cells with colorless walls. This is followed by a 

 second layer of thin-walled parenchyma cells. The nucellus con- 

 sists of an indefinite granular mass, followed by the endosperm, 

 and the thin-walled cells of the embryo. 



CARYOPHYLLACEAE, PINK FAMILY. 



Soap wort or Bouncing Bet {Saponaria officinalis L.). 



The kidney-shaped, black, roughish seeds consist of tangentially 

 elongated, thick, black, rough cells, the outer layer being brownish 

 colored, while the cell cavity is red or blackish brown. The inner 

 walls of the testa are thinner, the cells are elongated and the inner 

 seed coat is much compressed. The nucellus is indistinguishable 

 from the inner seed coat. This is followed by the endosperm. 



