The flattened pads, known as nopales, of some Opuntia cactus are de-spined and used in salads, soups, tacos, and entrees.
(Due to its hallucinogenic properties, it's illegal for non-tribe members to grow or own this cactus.) For example, Native Americans have long used peyote cactus Lophophora williamsii for medical and religious purposes. Many wildlife find these fruits tasty, and in some cases, help disperse the seeds in their dung.Ĭactuses are prized as ornamental indoor plants and as outdoor landscaping plants, but there are other uses too. Pollinated flowers develop into pulpy fruits with lots of small seeds. Various bees, beetles, birds, bats, and moths are important cactus pollinators. When the soil dries up, so do the teeny rain roots.Ī cactus blooms during or at the end of the rainy season-often large, showy flowers that last just a few days. When rain dampens the soil, small "rain roots" quickly sprout from perennial roots. While very tall cactuses grow some deep roots to anchor them in place, most cactus roots spread out and grow close to the surface, where they can quickly soak up even meager amounts of rain. Glochids may look soft and fuzzy, but they are barbed and wickedly sharp! In many types of cactus, minute bristles called glochids (GLOH-kidz) also grow from the areole. Although other plants may produce spines, thorns, or prickles, only cactuses have areoles. The spines grow from tiny, regularly spaced bumps on the stem, called areoles, which are modified buds. Actually, a cactus' spines are its leaves, adapted to suit a cactus' lifestyle. Looking at the thick, succulent stem of a spiny cactus, you might think that these plants don't have leaves. When the sun comes up, the stomata close the plant converts the storage molecules back into CO2 and photosynthesis fires up. Only certain types, including cactuses, convert nighttime-acquired CO2 into molecules they can store until daylight comes. Taking in CO2 at night isn't an option for most plants. Cooler nighttime temperatures mean that these plants lose far less water through open stomata. And, a cactus' stomata open only at night to take in CO2. A cactus' stomata are sunken slightly, which shades them and protects them from wind. At the same time, they lose water vapor through these same stomata. In fact, a cactus just might have the hardest-working stem in the plant kingdom!Īll plants take in the carbon dioxide (CO2) they need for photosynthesis through tiny openings called stomata (singular is stoma). A strong, thick cuticle helps prevent water loss, but that's only part of the story of how these amazing plants survive in extreme heat and arid conditions. A cactus stem may be cylindrical, spherical, or flattened.