) ee 
270 BOTANICAL GAZETTE [ocroser 
xerophytic seed-plants named above do in the spermatophytic society. 
The lichens composing the society, naming the genera in the order 
of the importance of one or more of their species as floral elements of 
the society, are as follows: 
Biatora myriocar poides (Fr.) Tuck. (Lecidea salvicola Flt.), the most common 
lichen of the society, and most abundant on the driest and most exposed portions 
of the riprap extensions; appearing as dark stains on the rocks, the nature of 
which can only be ascertained with hand lens. 
Bacidia (Biatora) inundata (Fr.) Kbr., replacing the last above to some extent 
in the more moist and shaded portions of the society, both on rocks and soil, the 
plant being as the name indicates somewhat hydrophytic in nature. This species 
also occurs sparingly mingled with the last in quite dry portions of the upper sur- 
face of the riprap extensions, where the thallus is more scanty than in its more 
natural habitat. The two plants, where occurring together, are very difficult to 
distinguish macroscopically. 
Cladonia mitrula Tuck., on earth and rock along the northward-facing wall; 
frequent; rarely on the extensions. 
adonia cariosa (Ach.) Spreng., on soil from disintegrated and somewhat 
shaded rock; rare. 
Cladonia cristatella vestita Tuck., on more or less disintegrated rock and 
usually on the lower and more moist portions of the riprap where more oF less 
shaded; rare. 
Cladonia furcata (Huds.) Schrad.; only one well developed plant seen and 
that in a well protected and moist place on the east basal part of the upper pore? 
of one of the riprap extensions. ‘ : 
Cladonia fimbriata coniocraea (Flt.) Wainio, in shaded or somewhat exposed 
places and more often toward the moist basal portions and sides of the nprap 
extensions; quite frequent; hitherto reported in Iowa under the varietal name 
tubaeformis Fr., which has also included the next. difficult 
Cladonia fimbriata apolepta (Ach.) Wainio, with the last, but rare and 
to distinguish. ; 
Cladonia fimbriata simplex (Weis.) Wainio, in well shaded spots; Tf; ei 
Towa, and easily confused with the second below, from which it differs in ef 
slender habit, its more sorediate condition, and its tendency to pe 
irregularly cylindrical forms of the last two above. 4 shaded 
Cladonia pyxidata neglecta (Flk.) Schaer., in more or less damp an 
places on disintegrating rock; frequent. 
Cladonia pysidata chlorophaea (Spreng.) Flk., in more or less os 
toward the base of the riprap extension; rare. ese two varieties 
previously been recognized in Iowa collections. 
Cladonia gracilis dilacerata Flk., on shaded or northw 
or less disintegrated surfaces: rare 
ard-facing and mo 
