14 • Rhodora [January 



difficulty of wind-blown spores having reached the seemingly inac- 

 cessible niche where this hybrid fern was found was no greater than 

 in some other instances of sporal migrations previously recorded by me. 



When first received the dual characters and resemblance of the new- 

 comer to A. Trichovianes and A. viride impressed me with the possi- 

 bility of its being a hybrid between those two species, but the absence 

 of the latter from that section altogether led me to treat it provisionally 

 as a form of .1. Trichomancs. The later and fuller information subse- 

 quently received, however, led to a further investigation that enabled 

 me to identify it properly through an admirable figure published by 

 Dr. Christ (1. c.) of a somewhat larger form from I^ugano. 



Three forms of this hybrid, to which specific names had been given, 

 were brought together under the ]>resent combination by Ascherson 

 and Graebner in the work already cited, and these are arranged by 

 Dr. Christ under comparative descriptions with his own account of 

 the large form from Lugano. 



The following brief diagnosis will, I think, sufficiently indicate the 

 general characters of our Vermont plant. Sporophyte small with the 

 habit of .1. Tricltomanc.f. Fronds (j to 10 cm. long, elongate, lance- 

 olate, broadest at base; sti])e and lamina of nearly equal length, stipe 

 and lower half of rachis brownish black as in .1. Trichomancs, then 

 green above as in .1. viride (the young growing fronds wholly green), 

 wingless; lamina pinnate with 7 to S pair of short-stalked pinnae, 

 and an enlarged terminal one with shallow lobes on one or both sides, 

 those below, to about the middle of the lamina, entire, the up])ermost 

 obovate, the lower ones broadening and becoming roundish ovate 

 with cuneate bases, below the middle increasing abruptly in size, 

 more or less lobed with rounded lobes, the second pair deeply lobed 

 or 3-parted, the lowermost pair fully 3-parted with the upper basal 

 lobe quite distinct. Margins crenulately denticulate. Sori short, 

 becoming confluent and covering the lobes at maturity. Indusium 

 irregularly denticulate. Proctor, Vermont, August 29, 1905, G. A. 

 IVooLson. 



The essential characters of the parent plants are reproduced in 

 their ofi'spring as follows: — 



1st. Truhomanes characters are seen in the brownish-black 

 stipe the lower portion of rachis, and partially also in the shape of the 

 upper pinnae. 



2nd. RUTA-MUR.A.KIA characters are seen in the long stipes and 



