1916] 
PALMER—PLANTS OF JASPER COUNTY, MISSOURI 399 
ing regions Ше thickets have quite a distinctive flora, for 
here are found many shrubs and vines and some herbaceous 
plants that seldom or never grow in other situations. Among 
the small trees are many species of Crataegus and Prunus, 
and a long list of sedges and grasses occur. Ulmus ameri- 
cana is frequently the only large tree along upland branches, 
and elsewhere large specimens of Populus deltoides occur 
far out on flat prairies. Along the branches and in wet de- 
pressions usually grow Salix Wardi, Amorpha fruticosa, 
Cornus Amomum, Penthorum sedoides, Hibiscus incanus, H. 
militaris, Cicuta maculata, Asclepias incarnata, Lobelia siphil- 
itica, and Lycopus americanus. Occupying somewhat drier 
situations are Celtis occidentalis, Corylus americana, C. ros- 
trata, Ribes missouriensis, Opulaster intermedius, Malus 
toensis, var. Palmeri, Rubus occidentalis, В. Andrewsianus, 
R. canadensis, Rosa setigera, Prunus hortulana, P. Munsoni- 
ana, Cercis canadensis, Zanthoxylum americanum, Ptelea 
trifoliata, Rhus glabra, R. copallina, Evonymus atropurpur- 
eus, Rhamnus lanceolata, Cornus asperifolia, C. Baileyi, Vi- 
burnum prunifolium, V. rufidulum, Symphoricarpos orbicu- 
latus, Smilax rotundifolia, S. hispida, Clematis Pitcheri, 
Menispermum. canadense, Cocculus carolinus, Celastrus scan- 
dens, Vitis cinerea, Ampelopsis cordata, Geum vernum, G. 
canadense, Cassia Medsgeri, Phaseolus polystachyus, Stro- 
phostyles umbellata, Galactia volubilis, Vincetoxicum caro- 
linense, V. Baldwinianum, Scrophularia marilandica, Dasis- 
toma macrophylla, Galium pilosum, G. circaezans, Triosteum 
perfoliatum, Rudbeckia triloba, Verbesina virginica, and Ca- 
calia atriplicifolia. 
In addition to the area, of which the main floral zones are 
outlined above, there are several rather distinct regions in 
which a close association between the underlying geological 
features and the present plant life is clearly traceable. 
The most extensive of these is the sand hill region or 
Barton upland, underlaid by Pennsylvanian strata, in the 
northwestern part of the county. This section is largely high 
prairie which slopes down to, and is limited by, the valleys 
