Nature Trail Stop 2: Cacti Alley

The second stop on the nature trail is Cacti Alley. This site has areas of exposed limestone and thus promotes a definite pattern in the vegetation type and distribution. As you can see in the tour below, pricklypear cacti (scientific name: Opuntia lindheimeri), are located around the rock edges or are even growing on top of rocks. Take a closer look at them by clicking on the hotspots in the tour below.

Nature Trail Stop 2: Cacti Alley

Pricklypear Cacti

When looking closer at the pricklypear cactus, notice the enlarged stems. The stems look more like a circular pad than what we think of as a stem. These stems store water for the plant, create plant tissue from solar energy through photosynthesis, and produce the pricklypear fruit. The pricklypear flower blooms from April to June, and pricklypears ripen during September. The pricklypear cactus is able to survive arid, or dry, environments because the enlarged stems store water for prolonged periods of time. The plant is thus suited for the drought conditions which occur periodically in the Edward’s Plateau region. At our site here on the nature trail, the cacti plants can grow near or on the rocks, because the plants are tolerable to rocky soils and are able to withstand the lack of soil moisture.

Look closely at the pictures in the tour again to see the spines that extend from the stem. Some species of cacti, such as the prickly pear, have spines instead of leaves. These spines protect the plant from predators seeking water and also reduce the amount of moisture the plant loses to the air that surrounds it. This characteristic also allows the prickly pear cactus to survive arid environmental conditions.

We now proceed to the next stop on the trail, the Limestone Pit. Before we go on, make sure you have completed your notes in the field notes worksheet and have recorded and classified the species at this site in your species inventory table.