IOWA ACADEMY OF SCIENCES. 221 



differ materially from the remainder, except that the cells are 

 somewhat smaller. The cell-walls of endosperm are thick- 

 walled, usually somewhat longer than broad, first row of cells 

 uniform. Cell walls colorless, consist of cellulose. Cell con- 

 tains fat and protein grains. 



PODOPHYLLUM PELTATUM L.^* 



Fruit large, ovate; a fleshy berry. Seed white, enveloped 

 by a pulpy arillus, which on drying becomes membranaceous. 

 Some writers do not admit that this is a true arillus. Seeds 

 elongated, three by one and three-fourths lines long, white. The 

 upper end of the seed larger than the lower, somewhat irregular. 



Epidermis. — Cells much larger than in Jeffersonia, light 

 colored, cuticle somewhat irregular, darker in color than cellu- 

 lose layer. The inner layer arched. Cell cavity large. 



Nutrient layer. — This consists of two layers of large cells, 

 longer than broad, with thin walls. Cells contain protein 

 grains. 



Osteosderid. — Apparently absent. 



Figment layer. — Does not differ essentially from Jeffersonia, 



Endosperm. — Bulk of seed is made up of white endosperm. 

 The cells of first layer, aleurone, are smaller than the remain- 

 der except that portion of the endosjierm next to the embryo. 

 The walls are thickened, white. Cells contain fat and protein 

 grains. Cell walls made up of cellulose. 



Embryo. — First row of cells smaller, and form a continuous 

 row. The cells contain fat and protein grains, but no starch. 

 Cell- walls made up of cellulose. 



KEY BASED ON ANATOMICAL CHARACTERS. 



A. Epidermal cells greatly elongated. 



1. Cell cavity of epidermal cells large. 



a. Stratification of epidermal cell-walls evident. 

 B. Thunbergii, B. amurensis. 



b. Stratification of epidermal cell-walls not evident. 

 B. canadensis, B. vulgaris, B cerasifna. 



2. Cell-cavity much reduced with very evident stratification. 



B. repens, B. aquifolium, B. nervosa. 



B. Epidermal cells not greatly elongated. 

 1. Epidermal cells brownish or black. 



Small, not much longer than broad, brown, 



Jeffersonia. 



14 Gray. The Genera of the Plants of the United States, pi. 3o-36. 

 16 Lla. Acad. Sc, Vol. v.] '[July 20, 1898.1 



