— 86 — 



pinnata, and on page 278 of the work, states distinctly that it is not the same as 

 P. rivularis, one would naturally think that he had seen the plant and knew 

 what he was writing about. 



The station for the Oregon plant as given me is: found on a rock bluff with 

 water running over it, about ten feet up a vertical wall rising from the side of 

 the creek, which is here almost a torrent: McKleay Canyon, Oregon; Coll. 

 Charles Potter, 16-5 — 1920. It gives me great pleasure to deposit half my 

 specimen in the herbarium of the Sullivant Moss Society. 



18 Palatine Road, Withington, Manchester, England. 



ON OUR AMERICAN FORM OF TIMMIA MEGAPOLITANA HEDW. 



John M. Holzinger 



Number 47 of my exsiccati was distributed under the name of Timmia 

 megapolitana Hedw. I have recently collected the plant again and have reex- 

 amined it with considerable care. Limpricht in Laubmoose^ devotes over a 

 page of detailed description to this plant. According to Limpricht 's Key (/. 

 P- 577) the leaf base ought to be yellowish and not hyaline: it is yellowish in 

 older Minnesota plants, but would even then be called hyaline (" wasserhell "). 

 He describes the upper, distal part of the leaf base as " papillose on the dorsal 

 side, with strongly thickened walls." These papillae are so insignificant that I 

 failed to find them on my own sections. Professor Chamberlain, however, 

 succeeded in making sections which demonstrate their presence. By his courtesy 

 I am permitted to publish his drawings. Fig. 2 shows the best that could be 

 found of papillae. This and fig. i are sections through the upper and lower 

 part of the leaf base respectively. 



Fig. I also demonstrates the presence, on the dorsal surface of the lamina, 

 of a layer of small flat cells extending from the costa toward the leaf margin, 

 becoming thinner and disappearing, leaving the lamina at the margin of one 

 cell-layer. 



The presence of these papillae is made of first diagnostic importance, as is 

 seen by the statement in the first line of Limpricht's key, page 577, and by the 

 italics in the description, page 578. Barnes, in his Key-, also uses this character. 

 The plant is monoicous, as it needs to be. The inner perichaetial leaves are 

 6-8 mm. long. One or two cf buds stand within them at the base of the seta; 

 they measure a little less than i mm., and are raised on a short stalk 0.32-0.4 

 mm. long; there are generally three enveloping leaves as long as the bud, which 

 have a loose elongated areolation ; the outer one is costate to above the middle, 

 while the others are costate to near the apex, and their margin is strongly serrate 

 above the middle; the antheridia are orange-yellow, and are raised on a short 



^ K. G. Limpricht. Die Laubmoose Deutschlands, Oesterreichs, und der Schweiz. Vol 2 5 

 578. 1895. 



^ C. R. Barnes. Analytic Keys to the Genera and Species of North American Mosses. Re- 

 vised by G. D. Heald, pp. 221. 1896. 



