spine

Spines are also modified leaves. In cacti, spines are wholly transformed leaves that protect the plant from herbivores, radiate heat from the stem during the day, and collect and drip condensed water vapor during the cooler night. In the many species of the spurge family…

…armored with flat, black, needlelike spines up to 20 cm (8 inches) long, just as the show depicts. Yes, chunga palms are really that intimidating. The dangerous, piercing spines provide a strong physical defense against herbivores seeking to eat or climb the plant, and the leaf stalks and fruit-bearing stems…

…plants by the presence of spines in areoles. Areoles are universal in the cactus family (at least in the juvenile phase) and have not so far been found in any other plant family. Almost all species of cactus have tufts of spines that develop from the areoles. These spines are…