A TRIP TO AN EAST TEXAS SANDSTONE OUTCROP

A Production of the Herbarium, Department of Biology, Texas A&M University (TAMU)
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Script by Monique Reed
  
Photographs by J. R. Manhart, H. D. Wilson , David C. Reed, Monique Reed, and Chris Best

Usage of these materials for other than educational purposes requires the written permission of the authors.
We are sorry not to have images of every plant---we will fill in the holes as soon as they become available. Meanwhile, you can look at other images in our Vascular Plant Image Gallery


INTRODUCTION

The vegetation of East Central Texas belongs to the associations known as Post Oak Savannah and Blackland Prairie. These two regimes sweep across the region in alternating bands, with savannah predominating on sandy soil and the prairies well-developed on more clayey soils. However, tucked within the savannah-prairie matrix are little pockets of a very different sort of flora--"islands" in a sea of sameness. Bogs, where they occur, support an astonishing array of different species (take a look at our trip to Flynn Bogs). Outcrops of bedrock, too, have floras all their own, and it is for one of these that today's expedition is bound.

Northeast of the town of Navasota in Grimes County lies a small but fascinating sandstone outcrop. This particular hill represents the north easternmost extent of the Oakville formation, a ridge of limey sandstone which runs southwest all the way to Duvall county. For most of its length, the Oakville formation is covered with other layers of rock and soil. Where the sandstone breaks the surface, though, a rich and unusual flora has developed. Many plants found here are more typical of the Edwards Plateau region of Texas, hundreds of miles to the west. One plant, discovered in the 1990's, appears to grow here and almost nowhere else in the world.

The botanists of Texas A&M's Biology department invite you to join them as they explore this unique environment.


Table of Contents--updated April, 2008


Species List For Outcrop
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