22 T. Holm — Studies in the Cyperacece. 



roundish or polyedric cells, none of which are differentiated as 

 palissade-cells. There are only a few, about seven, mestome- 

 bundles, of which the median one is the largest ; they are all 

 surrounded by thin-walled and colorless parenchyma-sheaths 

 inside of which we meet with a typical mestome-sheath. The 

 hadrome-part is rather large, and contains a number of vessels. 

 There are groups of stereorae on the leptome-side of the 

 mestome-bundles, while this tissue is almost wanting on the 

 hadrome-side, excepting in the median bundle. Eeservoirs of 

 tannin were noticed as being very abundant in the mesophyll. 

 A more complete structure is shown by the long leaf-blade of 

 F. squarrosa (fig. 14). Epidermis consists of very large cells 

 on the superior face of the blade, and is developed as " bulli- 

 form-cells" above the midrib and two of the largest mestome- 

 bundles. Hairs are abundant in this species, and are present 

 as very short ones on the superior face of the blade, while 

 those of the margins and the inferior face are long and sharply 

 pointed. The stomata (fig. 15) are very prominent, and seem 

 only to be developed on the inferior face of the blade. The 

 mesophyll is well developed, consisting of hexagonal very 

 closely-packed cells, while a large lacune is to be seen between 

 each of the two mestome-bundles. These last are surrounded 

 by colorless, thin-walled parenchyma sheaths as well as by the 

 usual mestome-sheath. and the larger bundles are on both faces 

 supported by some small groups of stereome. 



The root 



of F. scirpoidea agrees in most respects with that of the other 

 Cyperacece, having a hypoderm inside the epidermis, and with 

 the characteristic radial arrangement of the bark-cells, of which 

 the innermost layer, as usual, is differentiated as an endodermis. 

 This endodermis shows, however, a very peculiar development, 

 since the cells, which are exceedingly thin-walled, are stretched 

 radially, as shown in our figure 19. The pericambium is, also, 

 here interrupted by protohadrome, and there are five distinct 

 groups of leptome in alternation with five large vessels, while 

 the innermost part of the root is occupied by fundamental 

 tissue. The root of F. squarrosa shows a much weaker struc- 

 ture, since the bark-parenchyma shows many lacunes on account 

 of the radial collapsing of the cell-walls. The cells of the 

 endodermis {End in fig. 16) are of normal shape and slightly 

 thickened. A large vessel occupies the center of the root, 

 and tannin-reservoirs were observed in the epidermis as well 

 as in the outer bark-parenchyma. 



We see from this brief anatomical sketch that there are 

 several structural characters, by which these two Fuirena- 



