1	"Leaves relatively broad, flat on both surfaces"	2
1	"Leaves terete to trigonous or triquetrous, up to ca. 3 mm diam."	5
2	"Sepals 4; leaves opposite throughout"	"Mesembryanthemum cordifolium"
2	"Sepals 5; leaves sometimes becoming alternate on flowering stems"	3
3	"Plant finely papillate (papillae on young stems c. 0.5 mm diam.); stems angular; sepals conspicuously keeled; petaloid staminodes subequal to sepals"	"Mesembryanthemum aitonis"
3	"Plant coarsely papillate (papillae on young stems 1–2 mm diam.); stems terete or angular; sepals not keeled; petaloid staminodes much exceeding sepals"	4
4	"Plant annual; ± prostrate, to 20 cm high, spreading; stem terete; pedicel 0–5(–12) mm long; flowers 10–20(–30) mm diam. receptacle c. 8 mm diam., sepals 4–8 mm long"	"Mesembryanthemum crystallinum"
4	"Plant annual or biennial (possibly annual under adverse conditions); plant with an erect central stem 30–60(–100) cm high; stem angled-ribbed; pedicel 20–30 mm long; flowers (15–)49–60(–70) mm diam.; receptacle 12–15 mm diam.; sepals 9–12 mm long"	"Mesembryanthemum guerichianum"
5	"Plants perennial; leaves withering and soon deciduous, branches retaining only the persistent leaf bases; innermost series of staminodes gathered around the stamens, forming a cone"	"Mesembryanthemum granulicaule"
5	"Plants annual; leaves persistent; innermost series of staminodes spreading and not forming a cone around the stamens"	"Mesembryanthemum nodiflorum"