A MORPHOLOGICAL STUDY OF PALLAVICINIA 
LYELLII 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 245 
ARTHUR W. Haupt 
(WITH PLATES XX—XXIV) 
Pallavicinia, according to SCHIFFNER’S (12) census, is repre- 
sented by 21 species, most of which are tropical. Later, SCHIFF- 
NER (13) added 2 European species to his former list, thus making 
5 species indigenous to the Old World. Pallavicinia Lyellii is found 
in the more humid parts of both the Northern and Southern Hemi- 
spheres; it grows near Chicago in a peat bog at Mineral Springs, 
Indiana. Pallavicinia, Symphyogyna, and Monoclea are included in 
the family Leptotheceae. The affinities of the Japanese genus 
Makinoa, described by MrvaxeE (9), seem to place it in this family, 
as is done by Cavers. The disposition of Monoclea is a matter of 
great difference of opinion, some, as JOHNSON (6), placing it with 
the Marchantiales. There can be-no doubt, however, as to the 
closeness of relationship between Pallavicinia and Symphyogyna, 
regardless of the classification of the other genera of the family. 
CAVERS (2) divides Pallavicinia into the two genera of GOTTSCHE: 
Blyttia and Mérckia. According to the Vienna code, the older 
name Pallavicinia must be retained; if ScHIFFNER’s subgenus 
Morckia (Gott.) is to be elevated to ponkiie rank, it must not be 
done at the expense of the name Pallavicinia. STEPHANI (14) sepa- 
rates the genus into the 2 sections PROCUMBENTES and DENDROI- 
DEAE; SCHIMPER, into the subgenera Eupallavicinia, Morckia, and 
Mittenia. Pallavicinia Lyellii belongs to the PROCUMBENTES OF 
upallavicinia division. 
Material 
Most of the material studied was collected by Mr. R. P. MASON, 
at Columbiana, Alabama, to whom the writer is greatly indebted. 
Additional material was obtained by Dr. W. J. G. Lanp, at Mineral 
Springs, Indiana. Most of the slides illustrating the antheridial, 
Botanical Gazette, vol. 66] [524 
