140 
Ohio Biological Survey 
-i^) and with it may occur the bulrush (Scirpus validus) and species of 
Eleocharis. Encroaching upon these, is a zone made up of a number of 
Carices and Scirpus. In places, cat-tails (Typha latifolia) may nearly 
fill the pond; or such species of broad-leaved amphibious plants as Alisma 
Plantago-aqiiatica, Litdvigia pahistris, and Penthonnn sedoidcs may com¬ 
pose the marginal zone. 
Very shallow depressions on the wet uplands are filled with water 
for only a short time. Their position is indicated throughout the year by 
Fig. 15. Juncus effusns forms the marginal zone of the pond in this clearing south¬ 
west of Mount Carmel. 
the patches of Scirpus atrovirens and Carex typhinoides, which usually 
surround or even fill them (fig. i6). 
The sedge zone is followed by a meadow association in which grasses, 
sedges and rushes often predominate. Other plants which commonly 
occur in the wet grassy meadows are Arisaema Dracoiitium, Cardamine 
hulhosa, Polygala sangiiinea, Viola papilionacea, Lythrum alatiun, Ludvi- 
gia altcrmfolia, llysanthcs dubia, Gerardia tenuifolia, Diodia teres, Hons- 
