200 Rhodora [October 



Among the European specimens examined by die writer only two 

 show the niucronulate base of the anther referred to by Maximowicz, 

 but in these the mucro is much shorter than in anthers of the Ameri- 

 can phrnt and in their other characters the specimens are clearly 

 referable to the European type. The mucronate base of the anther, 

 then, although not an invariable character, is worthy at least of second- 

 ary consideration in distinguishing from the European and the Arctic 

 species the plant of Eastern America and Asia. 



In the European Pyrola rotundifoHa the anther-cells are slightly 

 constricted above, forming very short nearly straight necks or tubes 

 through which open the pores. In the Arctic /'. grandiflora these 

 necks are essentially wanting; but in the plant of temperate America, 

 Japan, etc., the necks are continued as prominent curved processes. 



In the form of its style the Arctic Pyrola grandiflora^ furthermore, 

 presents a character which seems to separate it very clearly from the 

 European P. rotundifoHa and its larger American and East Asian rep- 

 resentative. In the two latter plants the style is terminated by a 

 distinct ring above which are the five protruding stigmatic lobes. In 

 P. grandiflora this ring is nearly if not quite obsolete. 



From these comparisons it seems that the plants of Northern 

 Europe, of the Arctic regions of Greenland and America, and of east- 

 ern temperate North America and northeastern Asia are well defmed 

 members of the subgenus IVu-laia. The two former are clearly refer- 

 able to J'yrola rotundifoHa, L., and P. grandiflora, Radius. The 

 plant of eastern America and Eastern Asia has, however, been very 

 generally accepted as identical with the Old World P. rotundifoHa. 

 Only one author, so far as known, has previously maintained for the 

 plant specific validity.' Robert Sweet, in 1830, gave the plant an 



rotiindifoliae tribmuitur, stylus corollam aequans vel superans, aiitherae veto 

 omnes basi mucioiuilatae. Ita iiueni etiani in americanis, nempe calycis lacinias 

 variabiles, antheras vuio mucionulatas. At in europaeis, ubi antherae muticae 

 postulantur, in permultis (scandinavicis, germanicis, galiicis) etiam mucionulatas 

 video." — Maximowicz, Bull. Acad. Imp. Sci. St. Pet. xviii. 623 (US72). 



1 Pyrola rotundifoHa, as published by Linnaeus in the Species I'lantaium (^96), 

 included the American as well as the European plant ; and among other citations 

 was that of " L'yrola noveboracensis. Cold, uoveb. 99." Colden's /'. )io7Yi>oracensis, 

 published in Act. Soc. Upsal. 1743, p. 122, no. 99, was probably the large Amer- 

 ican plant, but I am unable to find that it has been taken up by any post-Linnean 

 author as a species distinct from /'. rotundifoHa. Treated by Linnaeus and all 

 subsequent authors as a pure synonym of r. rotundifoHa, the pre-Linnean name, 

 P. noveboracensis, can hardly be given nomenclatorial precedence over the post- 

 Linnean /'. atneritana. Sweet. 



