174: T. Holm — Studies in the Cyperacece. 



thin-walled in L. maeulata and form a projection in the shape 

 of a minute papilla (fig. 2), while no other 

 epidermal projections were observed in any 

 of the species examined. The outer epi- 

 dermis-cells, which lie between the stereome- 

 bundles, are very large and round in trans- 

 verse sections except in L. argentea, in 

 above the stereome which the radial walls have become stretched 

 from epidermis of the so as to render the lumen narrow. It is,, 

 stem of L. maeulata. a ] so? to \> e no ted that the epidermis in Z. 

 argentea forms very prominent ribs on each 

 side of deep furrows in which the stereome is located. Similar, 

 but more shallow, furrows are also noticeable in Z. maeulata 

 and Z. sphacelata above the stereome. In Z. microcephala, 

 however, furrows are, also, present, but the adjoining project- 

 ing, ribs are not here due to the increased size of epidermis, but 

 to the stereome. These species of Lipocarpha thus illustrate a 

 singular variation regarding the location of the stereome : 

 being situated in furrows as in Z. maeulata, Z. sphacelata and 

 Z. argentea, or in the projecting ribs in Z. microcephala. The 

 presence of similar furrows in the stem has, also, been men- 

 tioned by E-ikli in Ficinia, Fuirena, Heleocharis and others ; 

 the stereome, according to this author, is located in furrows in 

 Heleocharis geniculata _R.Br. and Fuirena, but located in the 

 projecting ribs in Ficinia stolonifera J^ees and F. tenuifolia 

 Kth. The interior layers of epidermis show a very uniform 

 structure and the walls are very thin. Stomata are present 

 and form longitudinal rows between the stereome-bundles ; 

 they are slightly projecting and the air-chamber is deep and 

 narrow. In this manner they are freely exposed in our species 

 with the exception of Z. microcephala, where they occupy the 

 deep furrows between the projecting bundles of stereome. 



As regards the mechanical tissue, the stereome, this is very 

 well represented in the stem of our species, forming relatively 

 large bundles on the leptome-side of the outer mestome-bundles 

 or on the hadrome-side of the inner ones. In the first case 

 the stereome-bundles are situated immediately underneath the 

 epidermis and border inwards on the chlorophyll bearing pali- 

 sade-sheath, that surrounds the mestome-bundles. It is gen- 

 erally thick-walled in our species, especially in Z. argentea 

 and Z. sphacelata. When considered in transverse sections, the 

 stereome forms roundish groups on the leptome-side of the 

 peripherical mestome-buntlles, where it is usually thick-walled ; 

 the stereome, that supports the inner mestome-bundles, is, on 

 the other hand, thin walled and forms an arch around the 

 hadrome of each bundle. Lipocarpha thus possesses a well 

 developed stereome, which accompanies the mestome-bundles, 



