Holm : Juxcus repens Michx. 



3G1 



besides in its southern ally 



iph 



Link. It seems to be 



rare in the Juncaceae, but is evidently characteristic o{ Junais ob- 

 tusatusY.v^g^m. and o{ J.falcatus E. Mey. judging from the diag- 

 noses in Buchenau's monograph: '* lamina interdum oblique ad 



latus deflexa, inde falcata/' 



The shoots of Jiincus rcpcns are hence very strongly flattened 

 throughout, and similar to what we have observed in Finibristylis 

 the leaves are truly distichous, besides turning the blades alter- 

 nately to right and left, thus all the blades on the one side of the 

 shoot point in an opposite direction to those on the other side. 



Jiincus rep 



not 



y 



however, resulted in acquiring the same internal structure as is 

 characteristic of the two species of F'unhnst)lis, mentioned above, 



/ 



Junci graviinifi 



case among the Cyperaceae, cited from Fufibristylis, 



Let us examine the structure in both in order to draw^ the 

 comparison as precise as possible. A leaf, or rather the half of a 



leaf-blade of Juucits rep 



i) show^s, as far as 



concerns the epidermis, a dorsiventral blade with the cells some- 

 what larger on the upper than on the lower face. Moreover the 

 upper epidermis is developed as thin-walled bulliform-cells in the 

 entire width of the blade, in which respect it agrees with both 

 species of Fiuibristylis. The structure of the mesophyll, however, 

 is very different, being in Juncus differentiated into a palisade- and 

 a pneumatic-tissue, while in Finibristylis only the palisade-tissue is 



developed. 



JiDuus rep 



more, of shorter cells, which are not arranged as regularly radiat- 

 ino- around the mestome-bundles as is the case with Fimbristylis, 

 Large lacunes traverse the mesophyll in Juncus and are Interrupted 

 only by obliquely placed diaphragms, accompanied by mestome- 

 anastomoses, small mestome-bundles Avhlch pass from the mestome 

 of the larger bundles through the interior of the diaphragms 

 and finally connect with the mestome of another bundle. Similar 



lacunes 



J 



observed in 



the two species of Finibristylis. Considering the stcreomc our 

 Juncus possesses no sub-epidermal groups of this tissue and there 

 is none in the leaf-margins either. But bordering Immediately on 



