508 Part IV. Chapter 2. 
Ulmus, Quercus obtusiloba and O. imdricaria) a host of herbaceous plants, 
such as Sedum pulchellum, Arenaria patula, Scutellaria nervosa, Talinum tere- 
tifolium, Astragalus plattensis, A. caryocarpus, Psoralea subacaulis, Baptisia 
australis, Houstonia patens, Anemone caroliniana, Viola pedata var. bicolor, 
Heliotropium tenellum, Phlox stellaria. The shrubs of these rock outcrops are 
Pielea trifoliata, Rhus canadensis (= R. aromatica), Forestiera ligustrina, Calli- 
carpa americana. 
The forests of Kentucky resemble in general features those of Tennessee. 
The central region is covered by a hardwood forest while in the western part 
the river swamps are occupied by Tarodium distichum and associated species. 
This part of the state, therefore, must be excluded from our description at 
this point because it has been described previously. One or two special 
features of the Kentucky flora now claim our attention. 
Chff Formation. The cliffs along the Kentucky and Dix rivers consist of 
limestone’.. Growing in the crevices of these cliffs, as chasmophytes, are 
found Szene rotundifolia, Polygala senega, Galium trifidum, G. circaesans, 
Nemophila microcalyx, Enslenia albida, Tradescantia pilosa, Arenaria patula 
and such trees as Fumiperus virginiana, Ulmus racemosa and Cladrastis tinc- 
toria (= Virgilia lutea). 
The Illinois cliff flora proper presents a rosette physiognomy not diffe- 
ring materially from that described in the Ozark Area on the Missouri side of 
the Father of Waters. The talus at the foot of the Illinois bluffs presents the 
same general aspect as on the Missouri side, according to Hus °), although the 
exposure is diametrically opposite. 
The talus slope (shingle) vegetation is richer on the Illinois side and comprises Stylophorum 
diphyllum, Arabis brachycarpa (= A. confinis), Viola striata, Hypericum Ascyron, Epilobium 
coloratum, Osmorrhiza longistylis, Bidens connata, Vernonia altissima, Phacelia bipinnatifida, P. 
Purshii, Euphorbia obtusata, Habenaria virescens (= H. flava), not found on the Missouri side. 
Large springs issue from the face of the Illinois bluff permiting the growth of numerous liverworts 
and algae. The occurrence of the lithophyte, Chlorotylium mammillosum which covers the rocks 
at Falling Spring with a green felt is to be noted here. 
Cave Associations. Southern Kentucky is a cavernous country where sinks 
or sink holes abound. Actaea alba occur only in sink holes with /mpatiens 
pallida, Scrophularia nodosa, Collinsonia canadensis, Asplenium angustifolium. 
Cystopteris fragilis is common in the crevices of moist limestone rock, while 
Asplenium ebeneum is on the rocks nearer the surface. Pellaea atropurpurca 
gTroWS at cave entrances, and Nephrodium (Polystichum) acrostichoides groWS 
in the woods near the top of the sink. Mats of walking fern Camptosorus rhi- 
zophyllus are also occasionally found in the bottom of sinks. About the entrance 
1) Evans, HARRY A.: The relation of the Flora to the geological Formations in Lincoln 
County, Kentucky. Botanical Gazette XIV: 310—314. 
2) Ecological Cross Section of the Mississippi River. ı9th. Rep. Miss, Bot, Garden 1908, 
127—253, 
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