172 T. Holm — Studies in the Cyjperacece. 



from a morphological view point, our genus possesses a main 

 inflorescence composed of a few short and almost roundish 

 spikes, surrounded by long, green involucral leaves. Each 

 spike bears a number of spirally arranged bracts, inside of 

 which are two minute, membranaceous scales, which surround 

 a flower. The position of these inner scales is somewhat 

 singular, being mediane, the lowest one being situated on the 

 posterior face of rhacheola, the upper one on the anterior face 

 or a little distance above the supporting bract. Both of these 

 scales are hyaline, nearly equal in length and apparently of the 

 same shape, but only the anterior supports a flower. The 

 question is then to decide whether we have " a one-flowered 

 spikelet " or " a single flower " before us, and this is a point 

 that has always been so much disputed. 



It would seem most natural, however, to define the two 

 scales and the flower as constituting a one-flowered spikelet, 

 wherein the lower scale would represent the prophyllon of the 

 rhacheola and the upper one the bract of the flower. The 

 position of the lower scale corresponds exactly with that of a 

 true prophyllon in other Cyperacece. Furthermore its anatom- 

 ical structure shows us two prominent stereome-bundles and a 

 distinct bicarinate outline, in contrast to the upper scale, the 

 bract, in which we have observed a mediane mestome-bundle, 



corresponding with other bracts. The 



— ^^ accompanying diagram of a spikelet of 



7/S^~~~*%S< ^' ?nacu ^ a ^ a shows us the supporting 



& \(-/o o pv_\M bract (B), in the axil of which is devel- 



7? (A \v ° 4o] J) 1 1 °P e d a rhacheola with a dorsal prophyl- 



' \vV^ — ^yyy' ^ on (^*) anc ^ a °ract (?)> which supports 



\^^f^^y the naked flower. This explanation 



\^o^^ seems to us the most natural, when we 



consider the minor inflorescences of 

 let tfL. mandate Expia- ? tlier Cyperaceas, where the rhacheola 

 nation in the text. is often provided with a basal, empty 



prophyllon, bicarinate or tubular as in 

 Carex, Cyperus, Dulichium, Fuirena and others. Although 

 Robert Brown did not define the lower scale as a prophyllon, 

 he considered, at least in his Botany of Congo,* the minor 

 inflorescence of Lipocarpha as a spikelet, not as a single 

 flower, a suggestion that was, also, followed by Kunth, Torrey, 

 Bceckeler and apparently by Baillon. Other authors have 

 held the opinion that there is " a single flower " instead of a 

 spikelet, for instance: Yahl, Nees von Esenbeck, Liebmann, 

 Michaux, Bentham, Eidley, Gray, Schumann, Pax and Goebel. 

 Pax describes the flower as possessing two prophylla : " eine 

 hermaphrodite mit zwei medianen Yorblattern versehene 



* For references consult the bibliography appended to this article. 



