428 Part IV. Chapter 2. 
sandy or muddy bottom. Probably the most common marine plant of the 
sounds, except perhaps Ulva lactuca, is Hypnea musciformıis, which grows in 
thick masses in every available situation. Scattered quite generally with this 
plant are tufts of Dictyota dichotoma here near its northern limit, associated 
with Rhabdonia tenera and Gracillaria confervoides‘). Codium tomentosum 
frequently occurs on shells in the sounds but more abundantly on the rocky 
breakwaters associated here with Dictyora, Padina pavonia, Sargassum vul- 
gare, upon which is found as an epiphyte Zeiocarpus siliculosus, while on ex- 
posed breakwater rocks are found Zuteromorpha and many delicate Rhodo- 
phyceae, chief among which are Dasya elegans, Erythrotrichia, Gelidium, 
Grinnellia americana, Trentepohlia virgatula with several species of Callı- 
thamnion, Ceramium and Polysiphonia. Zostera marina is abundant in the 
sounds and on its leaves flourishes Melobesia pustulata. — Paralleling and 
fringing these sounds and inlets are the salt marshes of the coast many of 
them very extensive in area. According to KEARNEY”) the following forma- 
tions may be distinguished in southeastern Virginia and North Carolina. 
Salt Marsh Formation. Salt marshes exist as a conspicuous element in 
the topography of the region bordering tidal streams and sounds up to the 
point where the water ceases to be brackish, but not infrequently, they cover 
wider areas in lagoons and bayous. At the meeting place of the salt and 
freshwater marsh vegetation, the plants of the tension line are Spartina 
polystachya and Seirpus americanus (salt water plants), associated with Sagik- 
taria lancifolia, Pontederia cordata, Polygonum hydropiperoides, Typha latifolia, 
Zizania aquatica (freshwater marsh species). 
Several associations of species may be distinguished in the salt marsh: 
Spartina stricta Association. This association in which S. szricta var. 
maritima is the most important species occupies the edge of the open water, 
associated with it as secondary species are Salicornia, Distichlis spicata. Where 
these plants grow the tidal range is marked, so that the plants are partially 
submerged at high tide. 
Juncus Roemerianus Association. This association occupies more 
ground than the former and is best developed on land that is merely wet a 
great part of the time and covered at most with only a few centimeters of 
water at high tide. Jumcus Roemerianus is perhaps the most abundant salt 
marsh plant of the region growing inside Spartina and affording a striking 
contrast to that plant by its dark green almost black color. In Virginia be 
sides Funcus Roemerianus among the most abundant plants is the shrubby 
Jva frutescens associated with Aster subulatus, Lythrum lineare, Statice caro- 
liniana, while atone point below Virginia Beach an assemblage of species 
ı) JoHNson, Duncan $.: Notes on the Flora of the Banks and Sounds at BEAUFORT, N. c 
Botanical Gazette XXX: 405—410. Dec. 1900, 
2) KEARNEY, 'THoMAs H.: The plant Covering of Ocracoke Island. Contributions U. S. 
National Herbarium 1900 V: 261—319; Report on a botanical Survey of the Dismal Swamp 
Region do. 1901 V: 321—585. 
