T. Holm — Studies in the Cyperacece. 47 



Art. YI. — Studies in the Cyperacew ; by Theo. Holm. 

 YII. On the inflorescence of the genus Sderia. With 

 figures in the text. 



This genus was first established by Bergius upon some 

 plants, which Rolander collected in Surinam in the year 

 1755. But some species of this same germs were known to 

 earlier authors, as appears from certain descriptions and figures, 

 though previous to Bergius, no attempt had been made to sepa- 

 rate these plants as generically distinct from other Cyperacew. 

 Tims Rheede, as early as the year 1686, figured a plant, 

 which Dillwyn identified with Sderia lithosperma • Mori- 

 son's " Cyperus Americanus major Lithospermi semine " 

 seems also to represent some species of Sderia, while 

 Plukenet's plant " Gramen cyperoides Lithospermi semine, 

 Virginianum" is of rather doubtful relationship. But 

 Sloane described and figured a true Sderia from Jamaica, 

 and Elmgren's "Sehoenus secans" belongs undoubtedly to 

 this genus. No further record seems to have been given of 

 this peculiar genus, for which Bergius selected the name 

 " Sderia" 



We might state at the same time, that the derivation of the 

 name, commonly given as " crfcXrjpta, hardness, from the indu- 

 rated fruit," is not correct. It is derived from cr/cXrjpos in the 

 sense of severe and merciless, since Bergius states that his 

 species Sderia Flagellum nigrorum was used as a whip for 

 the punishment of slaves in Surinam. The sterns of this 

 species are exceedingly sharp-angled and prickly, and tied 

 together they formed a most cruel and painful instrument of 

 punishment, hence the derivation from a/c\r)p6s. 

 ■ Examining the generic diagnosis given by Bergius, it is 

 interesting to notice that he observed the perigynium, alluding 

 to it in the following words: " Semen, basi cinctum pericheetio 

 membranaceo, ciliato-setaceo." This term " perichsetium " was 

 adopted by Bischoff for those membranaceous or setace- 

 ous organs which are often observed in female flowers of cer- 

 tain plants. Besides this, Bergius mentions the distichous 

 bracts, the bony, snow-white fruit and the unisexual flowers, 

 which characters are perfectly sufficient for the establishment 

 of the genus. Most peculiar is the structure of the so-called 

 perigynium or discus of the female flower, which Eichler 

 thought might represent abortive stamens. It shows great dif- 

 ferences of structure in the various species. In Sderia pauci- 

 flora Muhl. it is a low triangular disk upon which three pairs 

 of minute wart-like organs are to be observed. We might 



