144 HARSHBERGER: PHYTO-GEOGRAPHIC SKETCH 
reached great size in the primeval forest, for some are left 
which attest this. Thus are found white oaks six to eight feet 
in diameter, buttonwood trees six feet across, white pine five feet 
in diameter, beeches four feet, black walnut trees four to five feet, 
tulip-poplars six feet, sassafras trees two feet and a half. The 
secondary species tolerant of the shade are the dogwood, Cornus 
florida L., red mulberry, Morus rubra L., service berry, Amelan- 
chier Canadensis (L.) Medic, bladdernut, Staphylea trifolia L., 
Judas-tree, Cercis Canadensis L., hazel, Corylus Americana Walt., 
witch hazel, Hamamelis Virginiana L., and striped maple, Acer 
Pennsylvanicum L., while as shrubs occur smooth alder, A/nus 
rugosa (Du Roi) K. Koch, spice-bush, Benzoin Benzoin (L.) Coul- 
ter, dockmackie, Viburnum acerifolium ., arrowwood, Viburnum 
dentatum L., stagbush, Viburnum prunifolium 1., strawberry bush, 
Euonymus Americanus L., wahoo, Euonymus atropurpureus Jacq., 
and pinxter flower, Asa/ea nudiflora L. (Rhododendron nudiflorum 
Torr.) ; Sambucus Canadensis, the elder, also occurs in the region 
and at present is found usually in open places with alluvial soil 
forming thickets of some denseness. The laurel, Kalmia J/atifolia 
L., high-bush huckleberry, Gaylussacia resinosa (Ait.) Torr. & 
Gray and deerberry, Polycodium stamineum (L..) Greene (Vaccinium 
stamineum L.), are found in the drier forest soils throughout the 
region. The lianes which grow upon the dominant and secondary 
forest trees are several grape-vines, Vitis cordifolia Michx., V. la- 
brusca L., V. aestivalis Michx., V. vulpina L. (V. riparia Michx.), 
Virginia creeper, Parthenocissus quinquefolia (L.) Planch., poison 
ivy, Rhus radicans L., and several species of the genus S7/az. 
The climbing bittersweet, Ce/astrus scandens L., moonseed, Ment- 
spermum Canadense L., Sicyos angulatus L., wild-yam, Dioscorea 
villosa L., and wild balsam apple, Micrampelis lobata (Michx.) 
Greene (Echinocystis lobata Torr. & Gray) are climbing plants 
found along the courses of streams. 
A peculiar type of this mixed deciduous forest is found on the 
serpentine rock formations of the region under consideration. The 
botanist can identify the serpentine areas, by the vegetation alone, 
for the species which are character-plants, although occurring 
elsewhere in the region, are here grouped together in such a man- 
ner and in such number, as to sharply delimit these areas from the 
