TORREYA 



December, 1907 

 Vol. 7. No. 12. 



LIBRARY 



LEUCOLEJEUNEA, A NEW GENUS OF HEPATICAE new YOR 



BOTANIC 



By Alexander W. Evans QARDEr^ 



In the writer's paper on the Lejeuneae of the United States 

 and Canada* three species are referred to the genus Archilej'eiiiiea 

 and are described and figured under the names A. clvpeata 

 (Schvvein.) Schiffn., A. Sclloiviana Steph., and A. concliifolia 

 Evans. While the close relationship which these species bear to 

 one another is emphasized, attention is called to the fact that they 

 present a number of peculiarities which are not shared by typical 

 members of Archilcjcunea, and the propriety of retaining them in 

 this genus is questioned. A thorough study of several Archile- 

 jeiineae from tropical America, where the genus attains its highest 

 development, soon made it evident that the importance of the 

 aberrant characters exhibited by A. clypeata and its allies had 

 not been overestimated, and it now seems advisable to separate 

 them generically from ArcJiilejeunea and to propose a new genus 

 for their reception. This may be characterized as follows : 



Leucolejeunea gen. nov. 

 Lejeunea/. p. G. L. & N. Syn. Hep. 1845. 

 Lejeunea, subgenus Archi-Lejeunea p. p. Spruce, Hep. Amaz. 



et And. 1884. 

 Archilejeunea p. p. Schiffn. in Engler and Prantl, Nat. Pflanzen- 

 fam. i^ : 130. 1895. 



Plants medium-sized to robust, pale-green or glaucous, neither 



glossy nor pigmented but sometimes becoming brownish with 



age or upon drying : stems prostrate, copiously and irregularly 



branched, the branches prostrate or slightly separating from the 



^substratum, similar to the stem : leaves loosely to densely imbri- 



<~~"" — . 



Q~. * Mem. Torrey Club 8 : 1 13-183. pi. 16-22. 1902. 



^^__^ [No. II, Vol. 7, of ToRREYA, Comprising pages 209-224, was issued November 

 ^19, 1907.] 



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