1906] Fernald, American Representatives of Arenaria verna 31 



SOME AMERICAN REPRESENTATIVES OF 

 ARENARIA VERNA. 



M. L. Fernald. 



The names Arenaria verna and A. hirfa have long been familiar 

 to American botanists, and they have been so long associated with 

 certain alpine and high-northern plants that their American applica- 

 tion is rarely questioned. A recent close examination of some plants 

 of this preplexing grouji has convinced the writer, however, that in 

 our interpretation of these names we have gradually wandered far 

 from their true European significance. 



In America the name Arenaria verna has been recently applied to 

 high-northern caespitose and strictly glabrous plants, while most of 

 the pubescent specimens have been assigned to var. hirta. All the 

 plants thus treated have very small petals, usually shorter than the 

 sepals or sometimes wanting. In Europe, however, the plant which 

 is understood as A. verna is usually very glandular-pubescent and 

 with very numerous comparatively showy flowers, the corolla equal- 

 ling or exceeding the calyx. In these characters the true A. verna is 

 obviously quite unlike the plants which ordinarily pass under that 

 name in America ; although a plant with characters as in typical A . 

 verna of Europe has been found very locally at high altitudes in the 

 Northwest, where many other European species unknown or essen- 

 tially imknown in eastern America (Pliegopteris alpestri.s', Eriophorum 

 opacum, Luziila glabrata, spadirea and arcuaia, Ranunculus aquatilis, 

 etc.) are known to occur. 



An attempt to clear the confusion surrounding the American plants 

 which have recently been called Arenaria verna has led the writer to 

 prepare the following synopsis. Two of the plants included are of 

 closer affinity to other species than to A. verna, but since in America 

 they have recently been confused with the latter species it is thought 

 best to include them in the present notes. 



* Leaves hnear-subulate, 3-ribbed: sepals with 3 essentially uniform parallel 

 ribs: seeds reddish-brown, 0.4-0.6 mm. long. 



Arenaria verna L. Caespitose, glandular-pubescent: branches 

 0.4-1.5 dm. long: panicle many-flowered: calyx equalling or scarcely 

 as long as the corolla, in fruit narrow-campanulate, 3-3.5 mm. long; 

 sepals lanceolate to lance-ovate, acuminate, with narrow hyaline 



