1 | Plants herbaceous. |
1' | Plants woody. |
2 | Leaves opposite. |
2' | Leaves in spirals or distichous. |
3 | Stipules fully amplexicaul, leaving annular scars. |
3' | Stipules semi-amplexicaul or lateral. |
4 | Inflorescences bisexual. |
4' | Inflorescences unisexual. |
5 | Receptacle urceolate; leaves with waxy glandular spots at the base of the primary vein beneath. |
5' | Receptacle (sub)globose, covered with peltate bracts; leaves without landular spots at the base of the vein beneath. |
6 | Plants with prickles, at least on the twigs and/or the leaves. |
6' | Plants without prickles. |
7 | Inflorescences involucrate. |
7' | Inflorescences not involucrate. |
8 | Inflorescences sessile; the staminate ones with free stamens among concentrically arranged bracts; the pistillate ones with one flower; stigmas filiform. |
8' | Inflorescences pedunculate or subsessile; the staminate ones with distinct flowers; the pistillate ones with several to many flowers, or if one-flowered, then the stigmas tongue-shaped. |
9 | Blade always hairy, margin dent(icul)ate; staminate inflorescences open before an thesis; pistillate flowers free or basally connate. |
9' | Blade mostly glabrous, margin entire; staminate inflorescences closed before anthesis; pisillate flowers connate, the free parts of the tepals conical nr cushion-shaped. |
10 | Pistillate inflorescences with numerous flowers; staminate inflorescences much longer than wide (cultivated). |
10' | Pistillate inflorescences with 1 or a few flowers, staminate inflorescences almost as long as wide. |
11 | Inflorescences bisexual. |
11' | Inflorescences unisexual. |
12 | Receptacle cylindric or turbinate; stamens 3, pistillode present. |
12' | Receptacle globose, or discoid (to turbinate); stamens 1-2(-3); pistillode absent. |
13 | Inflorescences staminate. |
13' | Inflorescences pistillate. |
14 | Inflorescences with bracts among the flowers. |
14' | Inflorescences without bracts among the flowers, involucrate. |
15 | Inflorescences with a discoid to globose receptacle, initially covered with peltate bracts. |
15' | Inflorescences spicate to subcapitate. |
16 | Flowers distinct; stamens 4. |
16' | Flowers indistinct; stamens less than 4. |
17 | Filaments longer than the perianth; pistillode present; plant often with snines. |
17' | Filaments shorter than the perianth; pistillode absent; plant without snines. |
18 | Inflorescences in the leaf axils. |
18' | Inflorescences on leafless branchlets or spurs on the older wood. |
19 | Margin of the receptacle (initially) revolute; blade more or less consoicuouslv hairy, when dry dull and brownish bove. |
19' | Margin of the receptacle not revolute; blade glabrous or sparsely hairv. when dry usually shining and greenish above. |
20 | Flower(s) embedded in the receptacle. |
20' | Flowers not embedded (free or connate). |
21 | Inflorescences with one flower. |
21' | Inflorescences with several to many flowers. |
22 | Inflorescences in the leaf axils. |
22' | Inflorescences on leafless branchlets or spurs on the older wood. |
23 | Flowers (at least in fruit) pedicellate. |
23' | Flowers sessile. |
24 | Stigmas 2 and unequally long, or 1. |
24' | Stigmas 2 and equally long. |
25 | Stigmas filiform to band-shaped; blade more or less conspicuously hairy, when dry dull and brownish. |
25' | Stigmas tongue-shaped; blade glabrous or sparsely hairy, when dry shining and usually greenish. |
26 | Inflorescences globose-capitate, not involucrate. |
26' | Inflorescences discoid-capitate, involucrate. |
27 | Uncinate hairs present; inflorescences on older wood. |
27' | Uncinate hairs absent; inflorescences in the leaf axils. |