6 
AMERICAN JOURNAL OF BOTANY 
[Vol. 9 
few big trees or by slopes toward eastern and northern exposures, a well 
developed growth can be observed of a large number of perennial plants, 
most of which are composites such as Solidago rigida L., S. Drummondii 
T. & G., Aster turhinellus Lindl., A. patens Ait., Helianthus occidentalis 
Riddell, H. petiolaris Nutt., H. orgyalis DC, Lepachys pinnata (Vent.) 
T. & G., L. columnaris (Sims) T. & G., Ambrosia hidentata Michx., A. 
psilostachya DC., Silphium laciniatum L., Elephantopus carolinianus Willd., 
Vernonia crinita Raf., V. altissima Nutt., Rudheckia triloba L., and the 
very beautiful Echinacea purpurea DC. Species of other families which 
are often found here are Monarda fisttdosa L., M. mollis L., M. punctata L., 
M. citriodora Cerv. (rare), Pycnanthemum flexuosum (Walt.) B.S.P., P. 
pilosum Nutt., Scutellaria canescens Nutt., S. pilosa Michx., Pentstemon 
Cobaea Nutt., P. hirsutus (L.) Willd., Gerardia grandiflora Benth. (often 
between oaks), G.flava L., Linum virginianum L., Euphorbia corollata L., 
E. heterophylla L. (rare in Butler County), Apocynum androsaemifolium L., 
A. cannabinum L., Asclepias tuberosa L. (rare), A. purpurascens L., A. 
quadrifolia Jacq., A. verticillata L. (occasionally), Amsonia Tabernaemontana 
Walt.; also Gaura coccinea Pursh, Cuphea petiolata (L.) Koehne, Tephrosia 
virginiana (L.) Pers., Baptisia bracteata (Muhl.) Ekl., and Pteris aquilina L. 
Several of these species are also to be found on treeless barrens, and some of 
them are common on the prairie-like areas. A semi-parasite growing on 
the roots of oaks, Comandra umbellata (L.) Nutt., is very common in the 
entire region. 
All these perennial plants usually form a dense vegetation, where a 
struggle for maintenance seems to exist, although there do not appear to 
be large areas covered only by one or two species. 
Where a little creek passes through the dry hills, although it may be 
dry during the greater part of the summer, different vegetation is always 
found to have established itself. The soil contains more organic matter, 
and on account of the humus it contains and keeps its moisture longer and 
better than the surrounding loam. In such areas one finds, besides the 
already mentioned spring flora, several other interesting species. Oakesia 
sessiliflora (L.) W^ats. forms whole groups; the creeping Asarum canadense 
L. covers whole patches, also Pedicularis canadensis L., Heuchera hirsuti- 
caulis (Wheelock) Rydb., and Mitella diphylla L.; whereas Trillium re- 
curvatum Beck and the early flowering annual Collinsia verna Nutt. are 
always to be met with. These species are all to be seen flowering in the 
spring and until early in summer, but later in the season they are gradually 
followed by Lobelia inflata L., Silene stellata (L.) Ait. f., Spigelia mari- 
landica L., Tradescantia virginiana L., T. rosea Vent., and a few species of 
ferns, also such species as we find in the ravines and little valleys. 
The climbing plants are not as well represented as they are in the valleys 
or in the rich lowlands. Very conspicuous here are two species of Passiflora, 
namely P. incarnata L., with large flesh-colored flowers, and P. lutea L., 
