Holm, Some nevv anatomical characters for certain Gramineae. 125 



leptoine and oü the sides of the hadrome; they are thin just 

 above the liadrome, but otherwise this sheath is constantly con- 

 tinuous in the large mestome-bundles. But in the smaller mestome- 

 bundles the sheath is not onlj thin-walled with the exception of 

 one or two cells beneath the leptome, but it is also interrupted 

 by the two vessels, at least in some instances. Such interruptions 

 of the mestome-sheath by the vessels has been noticed before, but 

 is not, however, frequently met with, and it is often difficult to 

 decide whether these cells belong to a mestome-sheath or whether 

 they are to be considered as mestome-parenchyma. In the present 

 case the test with concentrated sulphuric acid proved these cells 

 to represent a mestome-sheath. A layer of thick-walled mestome- 

 parenchyma occurs between the leptome and hadrome, but only 

 in the largest bundles. 



Schedonnardus paniculatus (Nutt.) Trelease 



is also a member of the Chlorideae, and we coUected this 

 together with the preceding on the plains near Denver, Colorado. 



The leaf is conduplicate with a distinct midrib, and is furrow- 

 €d on both faces, though but slightly so on the lower. Most 

 of the epidermis- cells are extended into short obtuse papillae, 

 rendering the leaf faces very scabrous; but no proper hairs were 

 observed. Small bulliform cells are developed on the upper face, 

 in the bottom of the narrow furrows, whicli in this species pass 

 over into a colorless tissue, that extends to the lower epidermis, 

 except on the sides of the midrib, where a small group of sub- 

 «pidermal stereome is located. The stomata occur on both faces 

 of the blade near the furrows and are slightly projecting, sur- 

 rounded by the papillae. The stereome is much better developed 

 in this genus than in Buchloe, and forms a large thick-walled 

 group below the midrib, triangulär in transverse section, besides 

 that a similar large group is seen on the leaf-margin. Minor 

 groups of this tissue also occur on the leptome side of the larger 

 mestome-bundles, but seems to be almost totally absent from the 

 hadrome-side. — Examining the structure of the mesophyll and 

 the mestome-bundles with their parenchyma- and mestome-sheath, 

 we find this to be absolutely identical with that of Buchloe. 

 Schedonnardus is, nevertheless, readily distinguished from Buchloe 

 by the strongly developed stereome in the midrib, the small bulli- 

 form cells, and by the absence of hairs, even if the other parts 

 of the blade show a similar composition. 



Bouteloua oligostachya Torr. 



This grass belongs also to the Chlorideae and is very frequent 

 on the dry plains of Colorado, where it forms large and very 

 deuse patches, otten resembling the staminate plant of Buchloe. 

 The leaf-structure is so much like that of Buchloe in regard to 

 the shape , the development and the distribution of the various 

 tissues, that we are unable to point out any other difference than 

 that the leaf of Bouteloua is a little thicker; the mestome-bundles 

 are nearly all oval and tlie broader ribs are, on both faces, 



