HISTOLOGY OF SMI LAX BONA-NOX. 485 



the species are here arranged in their systematic order, for conven- 

 ience of comparison. The following is a synopsis of the species of 

 each formation which are described below: 



I. Maritime formations. 1 



A. Salt Marsh formation: Oxycoccus macrocarpus. 



B. Sand Strand formation: Smilax bona-nox, Helianthemum canadense, Hud- 

 sonia tomentosa,Lechea maritima, Gelsemiam sempervirens,* Galium hispidulum. 

 L( > n icera se mperviren s. 



II. Inland formations. 



A. Dry Land formations. 

 1. Forest formations. 



(a) Mixed Forest: Asarum virginicum, Per sea pubescent, Liquidambar styraci- 

 flua,Malus august if alia, Be.r glabra, Batodendron ( Vaccinium) arboreum, Symplo- 

 cos tinctoria, Styrax grandifolia, Gelsemium sempervirens, Lonicera semper rirens. 



•2. Cleared Land formations (noncultural). 



(b) Shrubby: Rosa earoUna . » 



(c) Herbaceous: Ascyrum stans, Hypericum pilosum, H. virgatum. Senecio 

 tomentosus. 



B. Fresh- water formations. 

 1. Palustrine. 



(a) Forest: Smilax laurifolia, S. walteri, Phoradendron flavescens, Magnolia 

 glauca, Persea pubescens, Liquidambar styraciflua, Itea virginica, Decumaria bar- 

 bara, Rosa Carolina, Mains angustifolia, Rex glabra, I. lucida. Acer rubrnm, Ber- 

 chemia scandens. Nyssa aquatica, Leucothoe axillaris. L. racemosa, Pieris nitida, 

 Xolisma foliositlora, Kalmia angnstifolia, Chionanthus virginica, Gelsemium sem- 

 pervirens, Lonicera sempervirens. 



(b) Open Marsh. 



Low Marsh formation: Pluchea foetida. 



Smilax boxa-xox L. 



Sand Strand formation (innermost dunes). 



Leaf thickish, evergreen, bifacial. 



Epiderm is: Ventral, cell walls thickish, the radial strongly undulate ; 

 cuticle nearly smooth. Dorsal, cuticle delicately wrinkled. Stomata 

 numerous, level with the surface, each bordered by a pair of irregu- 

 larly crescent-shaped subsidiary cells, the inner walls of the guard 

 cells strongly thickened. Hairs none. 



Palisade in one layer of short, wide cells. Pneumatic tissue rather 

 compact. 



1 The following maritime species which occur in the Dismal Swamp region were 

 described by the author, as to their leaf anatomy, in Contr. IT. S. Nat. Herb., vol. 5, 

 pp. 285 to 312 (1900): 



Sand Strand.— Panicum amarum Ell., Hpartina patens (Ait.) Muhl., Uniola 

 paniculata L..Myrica carolinensis Mill.. M. cerif era L.,Quercus virginiana Mill., 

 Q, laurifolia Michx.. Zanthoxylum clava-herculis L., Oenothera humifusa Nutt.. 

 Physalis viscosa L., Iva imbricata Walt. 



Salt Marsh. — Spartina stricta (Ait.) Roth. Juncus roemerianus Scheele, Kos- 

 teletzkya virginica L.. Mormiera monniera (L. ) Britron, Solidago sempervirens L., 

 Aster tenuifolius L., Iva frutescens L.. Borrichia frute-cens (L.) DC, 



a The names of species which normally occur in more than one formation are 

 printed in italics. 



