Holm — Studies in the Cyperaceoe. 299 



similar discoloration. But the very long involucre (" involucro 

 longissimo ") does not fit as well for a Dichromena as for a 

 Kyllinga, and our K monocephala has, as we remember, the 

 involucral leaves very long, much longer than in any species 

 of Dichromena. The character " capitulo subrotundo " is, 

 also, without doubt meant for the Kyllinga, since Linnaeus 

 would surely not have overlooked the several spikes in Dichro- 

 . mena with the flowers and bracts almost u biseriate." We 

 really feel assured that if Linnaeus had seen our Dichromena, 

 he would rather have referred it to Cyperus, on account of its 

 biseriate bracts, etc. It is, furthermore, difficult to detect any 

 organ in Dichromena which Linnaeus observed to be so con- 

 spicuous in order to name the species " coloratus" The inflor- 

 escence of Dichromena leucocephala is, as its name indicates, 

 snow-white, while that of Kyllinga is purplish-dotted. 



The later editors of Linnaeus' works, for instance Murray 

 (1. c. xii), refer Schmnus coloratus and S. niveus respectively 

 to K. monocephala and K. triceps, and Giseke (1. c. x), in 

 accordance with Rottbcell (1. c. xiv), makes the following state- 

 ment : "Kyllinga Rottbcelli adeo similis est Schoeno, ut duae 

 ejus species a Linnaeo patre sub illo comprehensae fuerint, 

 nomine 'colorati et nivei' quae jam Kyllinga monocephala et 

 triceps vocantur." Finally, Willdenow (1. c. xi) reached to 

 the same conclusion as Giseke and Rottbcell, and it must be 

 noted that this author, Willdenow, states that he had seen 

 specimens of Kyllinga monocephala, a fact that perhaps will 

 be sufficient to decide the identity of the Schoemos with the 

 Kyllinga, instead of with our Dichromena. 



In considering now our plants, they are of a very singular 

 aspect with their partly discolored involucre and white spikes, 

 but an examination of the details will soon show that our plants 

 are not different in any essential particular from most of the 

 other genera of the Scirpew. The genus Dichromena, for 

 instance, has three characters in common with Cypencs, viz : 

 the almost biseriately arranged bracts and flowers, the lack of 

 bristles, and finally the development of one of the internodes 

 of the stem into a long scape with the bracts and inflorescences 

 crowded at the apex. But it is at the same time readily dis- 

 tinguished from Cyperus by the achene, which in Dichromena 

 is crowned with the persistent base of the style. 



Let us pass to examine the internal structure of our 

 plants, beginning with the species leucocephala. This species 

 shows the general features, which are known to be character- 

 istic of the Cyperaceoe, besides that there are a few points in 

 which it seems to differ from all the others which, so far, have 

 been examined. The stem-leaf has a long flat blade, which is 

 perfectly smooth like the other parts of the plant, and green 



