IOWA ACADEMY OP SCIENCES. 219 



CAULOPHYLLUM THALICTROIDES MicllX. 



Fruit and seed characters. — Dr. Gray^^ong ago called attention 

 to the disappearance of the thin pericarp soon after fertilization 

 owing to the pressure of the growing seed. The ovary con- 

 tains two stalked ovules Seeds at maturity three lines long, 

 stalked, globular, blue, covered with a glaucous bloom, four 

 lines in diameter. The bony inner part of the testa dark brown, 

 hard, with a conspicuous white horny endosperm. 



Epidermis. — Cells somewhat longer than broad, thick- walled, 

 brown. The cuticle even, cuticularized layer thicker than 

 internal layer. Cell cavity much reduced. 



Nutrient layer. — Variable in thickness. This is followed by 

 thick- walled parenchyma cells; containing more pigment than 

 the parenchyma cells. The osteosclerid layer absent. 



Nucellav layer — This is very much reduced and compreseed. 

 The cells contain a large amount of protein in the shape of 

 small grains. 



Endosjjerm. — The bulk of the seed consists of endosperm. 

 The cells are very thick-walled, and on the addition of water, 

 swell. The cells of internal part of endosperm are elongated, 

 smaller and thicker walled. 



JEFFERSONIA BiNATA Barton. 



Fruit stipitate, coriaceouSj obovate, dehiscent by a slit at the 

 top, with a persistent short style, seven lines long. Seeds 

 numerous, slightly curved, oblong arillate laterally, three lines 

 long. Testa brown, shining, longitudinally wrinkled. Hilum 

 in a depressed cavity on outer side the persistent straw-colored 

 arillus. 



Epidermis. — The cells are rather short, exterior wall greatly 

 thickened, the cuticle covering the surface evenly, darker in 

 color than the cuticularized layer. The internal wall narrower 

 and arched above. Cell cavity considerably reduced. 



Nutrient layer. — This is more strongly developed than in Gau- 

 lophyllum or Diphylleia, consists usually of about six rows of 

 cells. The first layer of cells does not differ materially from 

 those below. The walls show peculiar thickenings in the 

 angles; resembling the mechanical element collenchyma found 

 in different plants. Walls colored brown. 



13 The Genera of the Plants of the United States. 81. pi. 32. 



