CACTACEAE - Cactus Family

Succulent, fleshy, spiny herbs, rarely succulent stems with alternate, simple leaves

Leaves - usually scalelike, much reduced

Areole - modified axilllary bud or a short branch or node with leaves or bud-scales modified into spines

Flowers are axillary at nodes

Sepals and petals are not clearly differentiated and are referred to as tepals

Pollinated by bees, hummingbirds, bats, hawk moths

30 to 200 genera, 2000 species, depending on treatment (splitters vs. lumpers), almost entirely limited to New World

Economic uses: ornamentals, fruits and pads of prickly pear are edible (Texas alfalfa), hallucinogenic plants (peyote)

Phylogenetic relationships were unclear until betalains were found in cacti

Cacti have evolved their characteristic habit in response to hot, dry climate; Pereskia is though to be primitive since it has leaves