Pteridophyten. — Floristik, Geographie, Systematik etc. 231 



Benedict, R. C. Studies in the Ophioglossaceae, L: A descrip- 

 tive key to Ophioglossum in the United States. (Torreya. VIII. 

 p. 71—73. April, 1908.) 



A brief synoptical treatment of the 6 species of Ophioglossum 

 found in the United States, the distinguishing characters being 

 given in the form of a descriptive key. The term "commonstalk" is 

 applied to the upright portion of the frond called by Prantl the 

 petiole. Maxon. 



Benedict, R. C, Studies in the Ophioglossaceae , II.: A descrip- 

 tive key to Botrychium in North America; group of B. lan- 

 ceolatum. (Torreya. VIII. p. 100 — 103. May, 1908.) 



For convenience the writer divides the genus Botrychium into 

 2 groups, these typified by B. lanceolatum and B. ternatum., respec- 

 tively. The former group, which is held to include B. virginianum , 

 is here dealt with, the several species (10) being treated at some 

 length in a descriptive key in which the more important diagnostic 

 differences are brought out. The geographic distribution of the 

 several species is indicated. Maxon. 



Eaton, A. A., Nomenclatorial changes in Isoetes. (Rhodora. X. 

 p. 42. March, 1908.) 



Two new combinations are here published, viz.: 



1. Isoetes heterospora A. A. Eaton, from Maine, is considered 

 referable to /. niacrosporn Dur. and receives the name Isoetes ma- 

 crospora var. heterospora A. A. Eaton. 



2. In compliance with Art. 49 of the Vienna code, the name /. 

 Dodgei A. A. Eaton is restored to the species recently known as 

 I. canadensis (Engelm.) A. A. Eaton (/. riparia var. canadensis 

 Engelm.). Thus, /. canadensis var. Robbinsii A. A. Eaton becomes 

 /. Dodgei var. Robbinsii A. A. Eaton. Maxon. 



Pfeiffer, W. M., Differentiation of sporocarps in Asolla. (Bot. 

 Gaz. XLIV. p. 445-454. pls. 31, 32. Dec. 1907.) 



The early stages in the development of mega- and micro-sporocarps 

 are found to be alike, namely, each begins with the forma tion of 

 a Single megasporangium and a sporocarp wall. Later microsporangia 

 grow from the stalk of the megasporangium. There are eight mega- 

 spore mother cells and sixteen microspore mother cells. In case a 

 megasporocarp is to be formed, thirty-one megaspores abort while 

 one continues growth, and the microsporangia cease growth. In case 

 a microsporocarp is to be formed, all thirty-two megaspores abort, 

 while the young microsporangia increase in size and n amber. The 

 frequent coUapse of the megasporangium in the microsporocarp led 

 to mistakes in the earlier accounts. M. A. Chrysler. 



Arnes, O., Notes on Habenaria. (Rhodora. X. p. 70—71. Apr. 1908.) 



Contains the foUowing new names: Habenaria dilatata media 

 {Lininorchis media Rj^db.), H. blephariglottis conspicua {H. conspicua 

 Nash.), and H. X Canbyi {H. cristata X blephariglottis). 



Trelease, 



