The Adaptations of the Century Plant

Foliage

• The leaves of the century plant are thick and fleshy, with a low surface-to-volume ratio and thick, waxy surfaces to minimize water loss. Special cells, called parenchyma, store water in the leaves. The leaves of the century plant have toothed margins and a sharp spine at the tip that deter browsing animals. This adaptation makes the century plant less-than-ideal for spots near walkways or where children or pets play.

Roots

• The century plant's root system is shallow and extensive. This allows the plant to absorb water quickly, which is necessary because desert rainfalls are often light and brief and the intense sun quickly dries soil out following rain. Good drainage around the roots of this plant is important and watering should be infrequent, especially in soils with a high clay content, to avoid problems with root and crown rot. You should also avoid digging around the shallow roots to avoid damaging them.

Photosynthesis

• Century plants use a type of photosynthesis, called crassulacean acid metabolism, to produce carbohydrates. With CAM photosynthesis, the stomata, or small openings in leaves that permit gas exchange, open at night when temperatures are lower and humidity is higher to take in carbon dioxide while minimizing moisture loss. The carbon dioxide is stored for the plant to use during the day while stomata are closed. When conditions are hot and dry, the plant can leave its stomata shut day and night.

Growth Rate and Reproduction

• The century plant grows and matures slowly, taking at least 10 years to store enough carbohydrates to produce its large flower stalk, which can grow more than 20 feet tall. The flower stalk features yellow flowers at the ends of a branching structure. After flowering, the century plant produces seeds and dies. The century plant also reproduces by producing offshoots around the base of the mother plant. Additionally, small plantlets form on the flowering stalk.