Vol. 4 No. II 



TORREYA 



November, 1904 



TWO HITHERTO CONFUSED SPECIES OF 

 LUDWIGIA 



By Roi.ano M. Hari'ER 



In August, 1902, I collected on Cumberland Island, Georgia, 

 specimens of a Lnchvigia which appeared quite different from any- 

 thing I had met with previously. From the available descriptions 

 it seemed to fit readily enough into L. virgata Mx., but it differed 

 in several characters, not mentioned in the descriptions, from the 

 plant of the pine-barrens which I had been accustomed to call 

 L. virgata. Later in the same season, and again in 1903, I met 

 with the same unfamiliar plant quite frequently in the lower 

 parts of the coastal plain, where it was often accompanied by the 

 plant which I had previously taken for L. virgata. 



Subsequent investigations in library and herbarium have con- 

 vinced me that my Cumberland Island plant represents an unde- 

 scribed species. Michaux's description of Ludwigia virgata, 

 though longer than his average descriptions, leaves a good deal 

 to be desired, as it fails to mention some characters (particularly 

 the reflexed calyx-lobes) now regarded as essential for this 

 species, but all the evidence obtainable from the works of 

 Michaux and his contemporaries tends to confirm my original 

 interpretation of his L. virgata. 



The other species turns out to have been often collected, 

 being perhaps the commoner of the two, but it does not seem to 

 have ever received a valid name, having always been confounded 

 with Michaux's plant ; so I venture to describe it below as new. 



[Vol. 4, No. 10, of ToRREY.v, comprising pages 145-160, was issued October 

 29, 1904.] 



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