Northern Piedmont Distriet. 467 
Sambucus ee 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 latifolia, high- 
bush iskiebery:; Vaceinium stamineum are found in the drier soils throughout the region. The 
laurel Kalmia high-bush huckleberry, Vaceinium stamineum are found in the drier soils, 
The smaller trees in this formation at Washington, D.C. are: Cornus florida, Cereis eanaden- 
sis, Hamamelis virginiana, Sassafras officinale, Castanea pumila, Juniperus vir. ne while as 
shrubs are: Cornus sericea, C. reger Viburnum acerifolium, V. dentatum, V. nudum, Gaylus- 
sacia resinosa, Vaccinium stamineum, vacillans, V. corymb ‚ Leucotho&@ racemosa, Andro- 
osu 
a mariana, Kalmia latifolia, Rhiodbdenären (Asien) on: Faden Ben 
The lianes which grow upon the dominant and secondary forest trees are several grape 
vines, Vitis cordifolia, V. labrusca, V, aestivalis, V. riparia (= V. vulpina); Virginia creeper, Am- 
pelopsis EEE poison ivy, Rhus radicans and several species of the genus Smilax. The 
Fig. 26. PVitis aestivalis Michx., a liane at Granogue Station near Wilmington, are 
Stem 5 feet 9 inches (1.752 m) in circumference ı foot (30.4 cm) from groun 
Photograph by J. T. Pennypacker. Deciduous Forest Formation. Piedmont a 
elimbing bittersweet, Celastrus scandens, moonseed, Menispermum canadense, Sicyos angulatus, 
wild-yam, Dioscorea villosa, and wild re ah Echinocystis (Mierampelis) lobata are clim- 
bing ae found along the course of the s 
he vi of the neighborhood of a DC. are Ampelopsis quinquefolia, Rhus 
ee Tecoma radicans, Vitis labrusca, V. aestivalis (see Fig. 26), V. cordifolia, V. 
riparia. 
A peculiar type of this mixed deciduous forest is found on the serpen- 
tine rock formations of the region under consideration‘). The botanist can 
identify the serpentine areas, by the vegetation alone, for the species which 
1) HARSHBERGER, JOHN W.: The Flora of the 'serpentine Barrens or southeast Pennsylvania. 
Science new ser. XVII: 339—343. 
30% 
