414 
3,000 specimens were collected from the 
prairie areas; numerous others from the 
adjacent rock ledges, upland woods, 
wooded coves, and basal slopes of the 
bluffs. These specimens now form a part 
of the collections in the herbarium of the 
Illinois Natural History Survey at Ur- 
bana. 
Collections and identification of hill 
prairie plants added several species to the 
known Illinois flora. Rudbeckia missourt- 
ensis was one of the rare plants reported 
(Evers 1951). The collections verified 
the present-day existence of certain spe- 
cies reported over a half century ago from 
Illinois but not collected in the state again 
until the field work for this study was 
undertaken. Mentzelia oligosperma is a 
notable example. The collections also in- 
creased the knowledge of the distribution 
of plants having somewhat restricted 
ranges in Illinois. Thus, it is now known 
that Bouteloua curtipendula ranges al- 
most continuously, in suitable habitats, 
from northern to southern Illinois along 
the western border, that Psoralea tenui- 
flora ranges southward into Monroe 
County, and that Houwstonia nigricans is 
quite common on loess slopes in south- 
western Illinois. 
The hill prairies contain prairie, wood- 
land, cultivated, and introduced species. 
The woodland species are occasionally 
found in prairie just as the prairie spe- 
cies are found in woodland, especially in 
adjoining border areas. The cultivated 
plants usually are escapes that have be- 
come established in the hill prairies. Some, 
Lespedeza stipulacea for example, had 
been planted in certain prairies or in ad- 
joining pastures by the landowners. Asia 
and Europe are the original homes of 30 
of the species found, North America of 
the remainder. 
Annotated List of Species 
This list was compiled from collections 
made and notes taken on the Illinois hill 
prairies visited. Field notes were used 
to supplement the distribution record but 
no species is included in this list unless it 
was collected from at least one prairie. 
The list is not intended as a complete 
flora of the Illinois hill prairies. Such a 
Ittinois NarurAL History SurvEY BULLETIN 
Vol. 26, Art. 5 
compilation would require much addi- 
tional time and many additional visits to 
these sites. In some cases, only the gen- 
eric name of a plant is given. Thus, the 
four species of grapes are included in this 
list under the term Vitis spp. In most in- 
stances, both generic and specific epithets 
are used. Any pertinent synonym is 
placed within brackets following the sci- 
entific name. Brief notes on the occur- 
rence of each plant or plant group follow 
its name. The name of each plant that is 
of foreign origin is preceded by an aster- 
isk’ (*)e 
Table 14, which summarizes presence, 
as discussed on page 392, contains a partial 
enumeration of the annotated list of spe- 
cies. Species found only on rock ledges, 
in coves, or in woodland borders near, but 
not in, the prairie stands of any site listed 
in table 14 are not indicated for that site. 
Some species mentioned in the annotated 
list are not included in table 14 because 
they are not native to North America or 
are not regarded as characteristic prairie 
species. 
LECIDEACEAE 
Lecidea spp. Lichens of this genus 
were found in 14 hill prairies. “—ITwo sam- 
ples were identified by Dr. C. W. Dodge 
of the Missouri Botanical Garden as L. 
decipiens and L. demissa. These plants 
grew between grass tufts under the shade 
of the grass foliage on either loess or fine 
rock fragments. 
MARCHANTIACEAE 
Reboulia hemisphaerica (L.) Raddi. 
This was a frequently encountered liver- 
wort on loess and rocks of hill prairies, 
where it grew in interspaces between 
bunches of grass. 
Musc!i 
An unidentified moss (or mosses) grew 
on loess of some hill prairies. All plants 
examined lacked sporophytes and accord- 
ingly remain unidentified. 
SELAGIN ELLACEAE 
Selaginella rupestris (L.) Spring. The 
rock selaginella grew in the sandy hill 
prairie at Devil’s Backbone. Although 
found on sandstone outcrops in southern 
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