Physiognomy and Structure: No Data Available

Floristics: These ponds are graminoid-dominated, generally with a layer of tall wetland grasses and sedges above a layer of semi-aquatic herbs. According to Bridges and Orzell (1989a) plant species dominance varies greatly depending upon water depth and the spread of colonial, rhizomatous species, and may also be related to geographic isolation of individual ponds and variations in local fire regimes. These ponds tend to lack woody plant species, but may contain scattered, stunted, Nyssa biflora and stems of Cephalanthus occidentalis. Bridges (1988) listed the following species as characteristic of this type: Eriocaulon compressum, Xyris fimbriata, Eleocharis equisetoides, Eleocharis quadrangulata, as well as two additional species, Carex verrucosa and Rhynchospora cephalantha, which were later shown to be more frequent in other pond types (Bridges and Orzell (1989a). Bridges and Orzell (1989a) reported the following species with frequency values of 60% or greater (listed in descending order of frequency): Eriocaulon compressum, Rhynchospora corniculata, Panicum hemitomon, Ludwigia sphaerocarpa, Xyris laxifolia var. iridifolia (= Xyris iridifolia), and Sagittaria graminea. Other herbaceous species may include Gratiola brevifolia, Hydrolea ovata, Proserpinaca pectinata, Pluchea rosea, Ludwigia pilosa, Bacopa caroliniana, Xyris sp., and Rhynchospora capitellata. This association may be distinguished by the absence of several herbaceous species which are reasonably frequent in other related flatwoods ponds of the region, such as Arnoglossum ovatum (= Cacalia lanceolata), Aristida palustris (= Aristida affinis), Rhynchospora latifolia (= Dichromena latifolia), Rhexia lutea, Xyris louisianica, Helenium drummondii, Juncus repens, Eriocaulon decangulare, and Rhynchospora rariflora. Several other species, such as Rhynchospora perplexa, Rhynchospora elliottii, Rhynchospora filifolia, and Rhynchospora gracilenta, are found much more frequently in other pond types (Bridges and Orzell 1989a). This association has been attributed to a seasonally flooded pond from an ancient channel of the Angelina River dominated by Panicum hemitomon and Rhynchospora corniculata. Other species present in this occurrence are Eleocharis quadrangulata, Hydrolea ovata, Boltonia diffusa, Carex joorii, Dichanthelium spretum, Sagittaria lancifolia, Brunnichia ovata, Proserpinaca palustris and Cephalanthus occidentalis.

Dynamics:  This community is species-poor because of deep and long flooding and is presumably less prone to invasion by woody plants than related shallower flatwoods ponds (Bridges and Orzell 1989a). A pond complex attributed to this type on the Stephen F. Austin Experimental Forest (Nacogdoches County, Texas) has been managed with periodic mowing to reduce woody encroachment (D.C. Rudolph pers. comm.).