114 Rhodora [May 



published accounts of the species have been noted and these will he 

 considered in order. Tin 1 differences between P. plitfyplu/lloidra 

 and /\ platypkylla will then be discussed. 



Although the lobes (of the stem-leaves) are usually orbicular and 

 arc sometimes even broader than long, as shown in Figs. 16-21, 2(5-29, 

 it is not unusual for some of the leaves to be longer than broad and 

 thus to approach in form the typical leaves of P. plati/phi/IIa, a con- 

 dition shown in Fig. 30. At the junction with the keel the cordate 

 expansion is strongly developed and tends to be conspicuously cris- 

 pate or irregularly folded. On the other side of the lobe, however, 

 although a cordate expansion may be present, as shown in Fig. 30, 

 it is much more usual for the lobe to narrow gradually and show a short 

 decurrenoe, as shown in Figs. 15, 26-29. Marginal teeth are often 

 present, just as they are in P. platypkylla, and tend if anything to be 

 more pronounced, but they are essentially the same in character. 



In typical material of P. platyphyUoidea the lobules are about as 

 wide as the underleaves and have broad rounded apices and narrowly 

 revolute margins. Unfortunately this typical condition is not always 

 realized, a fact clearly brought out by Gottsche's figures of the species, 

 which were drawn from an authentic American specimen in the 

 Lindenberg herbarium. These figures were issued with No. 372 of 

 Gottsche and Rabenhorst's Hepaticae europaeae, and are here repro- 

 duced as Figs. 14 2"). It will be noted that many of the lobules shown 

 are narrower than the underleaves, that some of them arc narrowed 

 toward the apex, and that the outer side only is recurved. The objec- 

 tion might perhaps be brought forward that Gottsche's figure was 

 drawn from a male individual, and that a plant often produced androe- 

 cia before it had reached the full luxuriance of which it was capable. 1 

 The writer, however, has observed female plants, bearing mature 

 sporophytcs with unispiral elaters, in which the lobules were fully as 

 narrow as those in Gottsche's figures and essentially like them in other 

 respects. Among plants of this character the Virginia specimens 

 collected by J. K. Small at the Falls of Holston River (No. 85) might 

 be especially mentioned, although similar specimens have been found 

 in other localities. It is clear, therefore, that the characters drawn 

 from the form and relative size of the lobule must be interpreted with 

 discretion. The remarks made under /\ platypkylla with regard to 

 the degree of decurrence and the occasional presence of teeth near 



1 Compare (ioolicl, Orguiiu^rupliie, 2d ed. 142. 1913. 



