The prairie and bordering woodlands of the Armand Bayou Nature Center, Harris County, Texas were sampled as an example of Texas Upper Coastal Prairie. The prairie is homogeneous and species-rich but shows very low dominance. Paspalum plicatulum, Dichanthelium spp., Carex cherokeensis, Andropogon virginicus, and Schizachyrium scoparium are the dominant graminoids. This prairie resembles the typical Upper Coastal Prairie of Texas but contains a greater number of eastern species with few southern or southwestern influences. Baccharis halimifolia has invaded the prairie and prairie climax species are no longer dominant. There is little evidence of a reduction in diversity due to brush encroachment. The woodlands are an oak and elm dominated riparian forest of the Upper Coastal Prairie with an important shrub component. Quercus phellos, Q. falcata, Ulmus americana, U. alata and U. crassifolia are common canopy species. Ilex vomitoria, Viburnum dentata, Callicarpa americana and Ligustrum sinense are the dominant shrubs.