1	"Stamens > 2 × as many as petals or > 15"	2
1	"Stamens 2 × as many as petals or fewer"	11
2	"Style 1"	3
2	"Styles or sessile stigmas > 1, sometimes partly fused at base"	7
3	"Stem fleshy, spiny (in some _Opuntia_ species only with glochids); sepals and petals indefinite in number and not sharply differentiated, in spirals"	Cactaceae
3	"Stem not fleshy, generally not spiny; sepals and petals each 3--7, clearly differentiated, in whorls"	4
4	"Herb or subshrub with rough, barbed, or stinging hairs"	Loasaceae
4	"Tree or shrub lacking such hairs"	5
5	"Ovary only 1/2 inferior, the free portion conic, especially in fruit"	"Hydrangeaceae {Carpenteria}"
5	"Ovary +- wholly inferior, the free portion, if any, rounded"	6
6	"Leaf generally dotted with embedded oil glands, often strongly scented when crushed; ovary chambers generally 2--5, all at 1 level; flowers variously colored"	Myrtaceae
6	"Leaf not gland-dotted, not strongly scented; ovary chambers generally 5 or more, some at different levels in the ovary; flowers bright red-orange to pale yellow"	"Lythraceae {Punica}"
7	"Shrub or tree, woody throughout, not fleshy; petals generally 4--5"	8
7	"Herb or plant woody only at base, generally +- fleshy; petals 4--many"	9
8	"Leaves opposite; fruit a capsule"	"Hydrangeaceae {Philadelphus}"
8	"Leaves alternate; fruit a pome"	Rosaceae
9	"Plant aquatic; leaf blades and flowers floating at water surface"	"Nymphaeaceae {Nymphaea}"
9	"Plant terrestrial; leaves and flowers not floating"	10
10	"Sepals 4--8; petals many"	Aizoaceae
10	"Sepals 2; petals 5"	"Portulacaceae {Portulaca}"
11	"Stamens opposite and = in number to petals"	12
11	"Stamens alternate petals or different in number"	13
12	"Shrub or tree"	Rhamnaceae
12	"Herb --- petals actually slightly fused at base, easily misinterpreted as free"	"Theophrastaceae {Samolus parviflorus}"
13	"Style 1, sometimes distally branched"	14
13	"Styles > 1"	21
14	"Plant a tendril-bearing vine; flowers unisexual, plant monoecious --- corolla sometimes so deeply divided that petals appear to be free"	Cucurbitaceae
14	"Plant not tendril-bearing; flowers generally bisexual"	15
15	"Ovules > 1 per chamber"	16
15	"Ovule 1 per chamber or perennial herb ovary"	18
16	"Herb (subshrub)"	Onagraceae
16	Shrub	17
17	"Stamens 5, free; leaves ovate or obovate to round, generally palmately 3--5-lobed, generally toothed; glands stalked or 0"	"Grossulariaceae {Ribes}"
17	"Stamens 10, fused in ring with staminodes; leaves linear needle-like, entire, opposite; glands embedded in leaves"	"Myrtaceae {Chamelaucium}"
18	"Leaves alternate"	19
18	"Leaves opposite; sepals and petals 4(5)"	20
19	"Plant a non-desert, sprawling, woody vine (flower stems +- erect); leaves smooth, dark green, often palmately lobed; inflorescence a cluster of umbels; fruit a berry"	"Araliaceae {Hedera}"
19	"Plant a low-desert perennial herb; leaves generally scabrous, pale green, unlobed; inflorescence +- a raceme; fruit an achene"	"Loasaceae {Petalonyx}"
20	"Perennial herb to tree; inflorescence an umbel, head, or cyme; fruit a drupe"	"Cornaceae {Cornus}"
20	"Annual; inflorescence a spike or spike-like raceme; fruit indehiscent, nut-like"	"Onagraceae {Clarkia heterandra}"
21	"Seeds 1--2 per chamber"	22
21	"Seeds generally several--many per chamber"	25
22	"Inflorescences of umbels or heads (spike in _Hydrocotyle verticillata_)"	23
22	"Inflorescences various but not of umbels, heads, or spikes"	24
23	"Leaves various [if round-reniform, plant terrestrial], glabrous or hairy; inflorescence generally compound umbel (occasionally simple umbel, head)"	Apiaceae
23	"Leaves round-peltate or -reniform, glabrous; plant aquatic with stolons or rhizomes, floating or rooted in shallow water or on mud; inflorescence simple umbel or spike"	"Araliaceae {Hydrocotyle}"
24	"Leaves alternate; hypanthium well developed; fruit a pome"	Rosaceae
24	"Leaves opposite; hypanthium very short or 0; fruit a capsule"	Hydrangeaceae
25	"Sepals 2; leaves fleshy"	"Portulacaceae {Portulaca}"
25	"Sepals 4--5; leaves generally not fleshy"	26
26	Herb	Saxifragaceae
26	Shrub	27
27	"Stamens 4--5"	"Grossulariaceae {Ribes}"
27	"Stamens 10"	"Hydrangeaceae {Jamesia}"