1	"Stamens > in number than corolla lobes or > 15"	2
1	"Stamens = in number to corolla lobes or fewer, generally <= 5"	6
2	"Plant spiny or bristly"	3
2	"Plant glabrous or +- hairy but not spiny or bristly"	4
3	"Stem very fleshy, generally spiny (in some _Opuntia_ species only with glochids); leaves 0 or conic to cylindric, fleshy; petal-like parts many, overlapping in several series"	Cactaceae
3	"Stem not or slightly fleshy, bristly with stinging hairs; leaves well developed, with expanded blade; petals 5, in 1 series"	"Loasaceae {Eucnide}"
4	"Petals or petal-like stamens many; leaves generally fleshy"	Aizoaceae
4	"Petals 4 or 5, petal-like stamens 0; leaves generally thin"	5
5	"Herbage glabrous to soft-hairy, sometimes glandular"	Ericaceae
5	"Herbage stellate-hairy"	"Styracaceae {Styrax redivivus}"
6	"Ovary actually superior, surrounded by but not fused to hardened or winged base of corolla-like calyx that simulates an inferior ovary; style passing through constriction separating calyx base from petal-like portion and joining to top of ovary"	Nyctaginaceae
6	"Ovary truly inferior, fused to bases of surrounding flower parts; style not passing through a calyx constriction"	7
7	"Leaves alternate or all basal"	8
7	"Leaves opposite or whorled"	11
8	"Tendrils generally present; flowers unisexual --- plant generally monoecious, leaves palmately veined, generally palmately lobed"	Cucurbitaceae
8	"Tendrils 0; flowers bisexual or unisexual"	9
9	"Inflorescence a head subtended or +- enclosed by involucre; calyx modified as pappus of bristles, scales, and/or awns, not green and leaf-like"	Asteraceae
9	"Inflorescence various but not a head; calyx of unmodified sepals, generally green"	10
10	"Stamens alternate corolla lobes; staminodes 0; flowers radial or bilateral; placentas axile or parietal"	Campanulaceae
10	"Stamens opposite corolla lobes; staminodes alternate fertile stamens; flowers radial; placentas free-central"	"Theophrastaceae {Samolus parviflorus}"
11	"Inflorescence a peduncled pair of flowers --- creeping subshrub, twining vine, or erect shrub"	12
11	"Inflorescence a head, spike, or cyme, or flowers solitary"	13
12	"Flowers sessile; fruits berries, sometimes fused"	"Caprifoliaceae {Lonicera}"
12	"Flowers on slender pedicels; fruits capsules, not fused"	"Linnaeaceae {Linnaea borealis var. longiflora}"
13	"Inflorescence a head or dense, head-like spike, subtended or +- enclosed by +- calyx-like involucre"	14
13	"Inflorescence various, not subtended or enclosed by +- calyx-like involucre"	16
14	"Anthers fused into tube around style"	Asteraceae
14	"Anthers free"	15
15	"Leaves opposite"	Dipsacaceae
15	"Leaves whorled"	"Rubiaceae {Sherardia}"
16	"Herb or subshrub"	17
16	"Shrub, tree, or woody vine"	18
17	"Stamens 4 or 5; corolla radial, not spurred or with proximal bulge"	Rubiaceae
17	"Stamens 1 or 3; corolla often bilateral, often spurred or with proximal bulge"	Valerianaceae
18	"Inflorescence a raceme or +- interrupted spike or flowers 1--2 in axils"	Caprifoliaceae
18	"Inflorescence a head or compound cyme"	19
19	"Leaves compound"	"Adoxaceae {Sambucus}"
19	"Leaves simple"	20
20	"Leaves 3--5-veined from base"	"Adoxaceae {Viburnum}"
20	"Leaves 1-veined from base"	Rubiaceae