1903] Blankinship,— Plant-formations of E. Massachusetts 129 
3. SAND-PLAIN FOREST Formation. Mesophytes. 
Habitat: Sand or sandstone substratum, nearly level and covered 
with an open forest growth, which affords suitable conditions of shade 
and humidity and moderate accumulation of humus; passing into (1) 
in more exposed situations, into (5) or (8) in low ground and 
into (7) along the coast. Species relatively few and vegetation often ` 
scattered. 
* Quercus alba, L. Cyperus filiculmis, Vahl. 
* Pinus rigida, Mill. Danthonia spicata, Beauv. 
* Carya alba, Nutt. Spiranthes gracilis, Bigel. 
* Quercus coccinea tinctoria, Gray. Hieracium venosum, L. 
° Gaylussacia resinosa, T. & G. Lupinus perennis, L. 
° Vaccinium vacillans, Soland. Helianthemum Canadense, Michx. 
? Rhus copallina, L. Baptisia tinctoria, R. Br. 
° Myrica asplenifolia, Endl. Viola pedata, L. 
Apocynum androsemifolium, L. Polygala polygama, Walt. 
Cypripedium acaule, Ait. Lespedeza capitata, Michx. 
Epigea repens, L. Deschampsia flexuosa, Trin. 
Linaria Canadensis, Dumort. Oenothera pumila, L. 
Asclepias obtusifolia, Michx. Festuca tenella, Willd. 
Gaultheria procumbens, L. Sericocarpus conyzoides, Nees. 
Crotalaria sagittalis, L. * Betula populifolia, Ait. 
Solidago odora, Ait. Tephrosia Virginiana, Pers. 
? Ceanothus Americanus, L. Prenanthes serpentaria, Pursh. 
4. HILLY UPLAND-FonEesT Formation. Mesophytes. 
Habitat: Argillaceous soil with slate or granite base, often glacial 
drift; rough hilly woodlands including most of the region, with a rich 
and diversified flora, but apparently with few species characteristic ; 
passing in exposed situations into (2) and in low ground into (6), (8), 
(9) or (11), but is often contiguous to and may pass into nearly all 
the other formations; often denominated “dry hillsides,” “rocky 
slopes,” “rocky open woods," etc. This is the dominant formation 
of the region. 
* Quercus alba, L. Viola ovata, Nutt. 
Q. coccinea tinctoria, Gray. Hedeoma pulegioides, Pers. 
* Q. rubra, L. Gerardia tenuifolia, Vahl. 
* Carya alba, L. G. quercifolia, Pursh. 
* C. porcina, Nutt. G. flava, L. 
* Prunus serotina, Ehrh. Lobelia inflata, L. 
* Sassafras officinale Nees. Solidago nemoralis, Ait. 
* Populus tremuloides, Michx. S. bicolor, L. 
