Definitions for Nature Trail Tour

Before we study the vegetation at the nature trail entrance, we need to be familiar with a few terms. On this trip, we will be classifying several different species according to their plant growth form. Plant growth forms are a way of classifying vegetation according to its physical characteristics, such as stem structure, stem size, and leaf shape. TheFreeman Ranch consists of eight plant growth forms: forb, graminoid, tree, shrub, vine, succulent, epiphyte, and parasite.

In this virtual tour we are looking at four of the eight plant growth forms. They are forb, graminoid, tree, and succulent.

Forbs consist of flowering plants that have soft stems and broad leaves. The Texas Bluebonnet is an example of a forb.

Graminoids are plants with narrow leaves, or stalks, and have grass-like characteristics. These plants include grasses and sedges, such as Texas Grama or Buffalo Grass.

Trees are defined as plants with a single stem, or trunk, which has a wood-like structure and texture. They also are over 3 meters (10 feet) tall and have branches that form a distinct crown. An example of a tree is the pecan tree.

Succulent plants contain tissue that can store water for longer periods of time than other types of plant tissue. The moisture is stored in the plant’s stem, leaves, or rootstocks and can be used as a source of water during times of little or no precipitation. Succulent plants often have a waxy, leathery appearance, and some succulent plants have spines as leaves. The Yucca is an example of a succulent plant.

Two other important definitions include:

Tolerance is the ability of a plant to survive certain environmental conditions. An example would be a plant that can withstand droughts. This plant is said to be drought tolerant.

Limitations are environmental conditions that a plant cannot withstand. For example, a tree may be able to survive in only well-drained areas. If the tree receives too much moisture for long periods of time, the tree could die. This characteristics of the tree is called a limitation.

If at any time during the tour you need to see the definition of any of these words, simply click on the link for the terms page, which is found at the bottom of each page in the tour.