1	"True leaves produced "	"Cactaceae - Group 1"
1	"True leaves absent or extremely small and inconspicuous (often soon shed) "	2
2	"Stem flattened or 2-winged at least in part; if 3–5 ribbed or cylindric then less than 12 mm wide and not continuously ribbed; mostly more or less spineless "	"Cactaceae - Group 2"
2	"Stem at least 3-winged OR with ribs OR tubercles "	3
3	"Stem at least 6 times longer than thick, scrambling, trailing or pendulous, often with aerial roots; spines usually weak and bristly OR very short OR none "	"Cactaceae - Group 3"
3	"Stem more or less erect, not scrambling and without aerial roots;spines often well developed "	4
4	"Stem long, cylindrical to columnar, at least twice as long as wide before flowering "	"Cactaceae - Group 4"
4	"Stem globular or depressed, less than twice as wide when flowering "	5
5	"Stem ribbed or, if with tubercles, the tubercles in more or less vertical rows "	"Cactaceae - Group 5"
5	"Stem tubercled, spirally arranged, or rarely both ribs and tubercles absent "	6
6	"Tubercles leaf-like or scale-like often giving the body the appearance of an artichoke or pine cone "	"Cactaceae - Group 6"
6	"Tubercles not leaf-like, mostly nipple-like, swollen, pyramidal or absent "	"Cactaceae - Group 7"