28 BOTANICAL GAZETTE [july 



r 



mis are small, and moderately thickened in the wings. Hairs of 

 two kinds are frequent : short and clavate ones {-fig. g), and some very 

 long ones, with slender pluricellular stalk and a small globular head, 

 the apical cells being extended into papillae {fig. 6) ; they both represent 

 glandular hairs. The cortex is thin- walled and contains chlorophyll, 

 besides druids of calcium oxalate; no palisades were observed. A 



com 



medullary 



thick-walled. The inner leptome represents much larger groups than 

 the outer, and an isolated leptomatic strand {fig. 14) occupies the 

 center of the pith. This central leptome may be followed through the 

 entire length of the stem, but in the basal internodes it is accompanied 

 by a few vessels which it partly surrounds ; thus the structure becomes 

 approximately hadrocentric. The pith is thin-walled and contains 

 neither starch nor druids. 



As a member of the Dermomyelodesmeae, Rhexia possesses also 

 some mcstome strands in the cortex, and these occur in this species 

 only in the wings, three in each wing and very small, but containing 

 a few elements of leptome and hadrome. 



With the exception of an occasional thickening of the cortex in the 

 wings, like a very feeble collenchyma, there is no mechanical tissue; 

 in the basal internodes the epidermis and cortex are thrown off, while 

 the endodermis remains intact and about four layers of pericyclic 

 cork are developed. It is in these internodes that a central mestome 

 strand occurs, with both leptome and hadrome. 



The shoot is terminated by a flower whose peduncle, although a 

 direct continuation of the stem, shows a somewhat modified structure. 

 It is cyh'ndric, but wingless, and the cortex contains no chlorophyll. 

 The mestome strands are bicollateral, but the inner leptome forms an 

 almost continuous band close to the hadrome, while in the stem inter- 

 nodes the inner leptome occurs as several distinctly separate strands- 

 No central leptomatic^trand was observed in the pith. 



The leaf 



The structure is bifacial. The cuticle is wrinkled on the upper 

 face, but does not show any prominent striation. Viewed en face 

 the lateral cell walls of the epidermis are undulate on the dorsal 



