Pammel — Caryopsis and Endosperm of some Grasses. 207 



Of the Phleoideae I have studied Phleum. A short account 

 of the anatomy of this and several related grasses is given by 

 Harz, 1 who states that anatomically it has the same structure 

 as Alopecurus and Agrostis. In Alopecurus the starch grains 

 are simple and compound, in Phleum compound or small and 

 simple. The aleurone grains are solidly packed in Phleum 

 and more abundant than in Alopecurus. 



Phleum pratense, L. The testa and pericarp are dark- 

 colored. The epidermal cells are thin-walled, elongated, some- 

 times slightly irregular. The testa consists of several rows 

 of thick-walled, dark brown cells much longer than broad. 

 The aleurone layer consists of a single row of cells relatively 

 thin- walled, somewhat variable in size, solidly packed with 

 aleurone grains. The nucellus is very evident as a remnant 

 in some places. The cells of this layer are thick-walled, 

 clear and colorless. The starch cells are much larger than 

 the aleurone, and contain somewhat angular starch grains, 

 probably compound. Protein matter present (PI. XVII. 12). 



Sporobolus, K. Br. Of the Agrosteae only Sporobolus cryp- 

 tandrus, Gray, was studied, but Harz has given accounts of 

 other representatives of this sub-tribe, among them Agrostis 

 alba, Calamagrostis, several species, and Ammophila. There 

 appears to be considerable difference between Ammophila 

 and Agrostis. In Ammophila there is considerable develop- 

 ment of both testa and pericarp, while both are only slightly 

 developed in Agrostis. 



Sjporobolus cryptandrus, A. Gray. The outer row of cells of 

 the caryopsis of Sporobolus is mucilaginous. The cells of 

 the testa are thicker-walled, much compressed. It is difficult 

 to distinguish the testa from the inner portion of the peri- 

 carp. The aleurone layer consists of a single row of thin- 

 walled narrow cells followed by the much larger cells of the 

 starch layer, the cells of which are densely filled with simple 

 grains (PI. XIX. 7). 



AVENEAE. 



Good accounts of the structure of several species of the 

 tribe Aveueae are given by Harz. 2 The same writer 3 figures 



1 1. c. 1270. a 1. c. 1320. /. 193. 3 1. 0., Deschampsia, 1311. 



