FEB 1964 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 10(5) -279-304 



TAXONOMY OF THE SUBGENUS PTERODES, GENUS LUZULA 1 



John E. Ebixger 2 



Eastern Illinois University, Charleston, Illinois 



The monocotyledonous genus Luzula comprises a wide ranging group of 

 grass-like plants having little economic importance except as occasional weeds. 

 The common name, woodrush, alludes to the characteristic habitat of shady 

 woodlands, which contrasts with the habitat of many other members of the 

 family Juncaceae. As generally treated, some 60 species are recognized, and 

 these occur on all the major land masses of the world, being particularly abun- 

 dant in Europe and Central Asia. No recent revision of the genus is available, 

 the last comprehensive treatment being that of Buchenau (1906). During the 

 past half century, numerous species and varieties have been described as new. 

 Moreover, since the discovery of unusual nuclear phenomena in this genus, ex- 

 tensive cytological studies have been carried out with many members of the 

 genus. Unfortunately little or no effort has been made to correlate these results 

 with the taxonomy. In view of the above, along with frequent difficulties en- 

 countered in attempting precise identification, a thorough taxonomic stud}' 

 seemed desirable. 



For more than a century the genus Luzula has been treated as comprising 

 three rather well defined subgenera. These were originally described by Grise- 

 bach (1844)' and their validity has been generally accepted since that time. 

 Furthermore, present anatomical information compiled by the author as well 

 as recent cytological findings indicate that these three traditional subgenera 

 should be recognized. In this article one of these subgenera (Pterodcs) has been 

 studied critically and a taxonomic revision is included. An attempt has been 

 made to account for every published name applied to this group from 1753 to 

 the present date. In all cases the original description of each taxon was con- 

 sulted, and whenever possible, the type specimen was examined. The subgenus 

 Pteroch ? was chosen for critical revision since a great deal of cytological data 

 were available. Also, breeding experiments involving most of the species were 

 conducted by Xordenskiold (1957) and in the present study an attempt will 

 be made to correlate these results with the taxonomy. 



During this study it was necessary to propose new names for some of the 

 taxa studied. In other instances names that had earlier been considered valid 

 have been reduced to synonymy. One new subgeneric name has been used. The 

 subgeneric name Luzula is used in place of the earlier name Gymnodes to con- 

 form to the International Code of Botanical Nomenclature (1956), Article 22. 



1 The present contribution is based in part on a thesis presented in June, 1961, to Yale 

 University in partial fulfillment of the requirement for the degree of Doctor of Philosophy. 



- The author expresses his sincere thanks to Dr. John R. Reeder, as senior advisor, for 

 his assistance and valuable suggestions. He is also indebted to the curators of the many her- 

 baria who sent herbarium specimens to be studied and to Dr. Hedda Xordenskiold, Agricul- 

 tural College of Sweden, Uppsala, who kindly sent specimens of the parental plants and hybrids 

 used by her while conducting breeding experiments in the subgenus Pterodes. 



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