1	Herbs	2
1	"Lianes, shrubs or trees"	4
2	"Styles 1; fruits unilobate"	"Croton setiger"
2	"Styles 3; fruits trilobate"	3
3	"Extrafloral nectaries 2 at top of petiole"	"Croton glandulosus"
3	"Extrafloral nectaries absent from leaf"	"Croton capitatus"
4	Lianes	"Croton caudatus"
4	"Shrubs or trees"	5
5	"Leaf lamina palminerved"	6
5	"Leaf lamina penninerved"	13
6	"Leaf lamina silver-white below"	7
6	"Leaf lamina green below (not silver-white)"	8
7	"Stipules linear-lanceolate, 3–6 mm long; leaf lamina below with dense overlapping peltate scales"	"Croton schultzii"
7	"Stipules lanceolate, 1.2–1.8 mm long; leaf lamina below with dense stellate trichomes"	"Croton tomentellus"
8	"Leaf lamina denticulate to crenate with 60–100 teeth"	"Croton arnhemicus"
8	"Leaf lamina denticulate to crenate with 30–52 teeth"	9
9	"Stipules lanceolate, 0.3–1 mm long"	"Croton armstrongii"
9	"Stipules linear to linear-lanceolate, 1.2–6 mm long"	10
10	"Leaf lamina with interlateral tertiary venation obscure below"	"Croton minimus"
10	"Leaf lamina with interlateral tertiary venation well developed below"	11
11	"Leaf lamina with 32–40 teeth; male flowers with pedicels 10–12 mm long; stamens 32–38"	"Croton waterhouseae"
11	"Leaf lamina with 10–28 teeth; male flowers with pedicels 1.5–7 mm long; stamens 10–24"	12
12	"Male flower petals 4–4.5 mm long, 0.8–1 mm wide; fruit oblong-ovoid, 3–17 mm long; seed 8.5–10.5 mm long"	"Croton aridus"
12	"Male flower petals 1.5–3.2 mm long, 0.5–1.5 mm wide; fruit depressed-globose, 5–8 mm long; seed 4–5 mm long"	"Croton multicaulis"
13	"Foliage silver-white to silver-green below due to presence of dense adpressed silver scales and trichomes"	14
13	"Foliage green to ferruginous below due to the absence of indumentum or the presence of uncoloured or ferruginous indumentum"	19
14	"Leaf lamina with obscure lateral venation"	"Croton insularis"
14	"Leaf lamina with discernible lateral venation"	15
15	"Branchlets with peltate scales only"	"Croton capitis-york"
15	"Branchlets with stellate trichomes, or with admixture of stellate trichomes and peltate scales"	16
16	"Branchlets with stellate trichomes only"	17
16	"Branchlets with either peltate trichomes, or an admixture of peltate scales and stellate trichomes"	18
17	"Leaf lamina with the lateral veins not prominently raised below; extrafloral nectaries sessile, visible above only"	"Croton phebalioides"
17	"Leaf lamina with the lateral veins prominently raised below; extrafloral nectaries stipitate to 1.8 mm long, visible above & below"	"Croton stigmatosus"
18	"Branchlets and leaf petioles with peltate trichomes only; extrafloral nectaries absent or circular"	"Croton mamillatus"
18	"Branchlets and leaf petioles with admixture of peltate scales and stellate trichomes; extrafloral nectaries ellipsoid"	"Croton simulans"
19	"Leaf lamina below with indumentum of peltate scales or peltate trichomes"	20
19	"Leaf lamina below with indumentum of stellate trichomes"	23
20	"Leaf petioles 2–5 mm long; lamina narrow-ovate, oblanceolate or obovate, margins entire to sinuate"	"Croton brachypus"
20	"Leaf petioles 4–36 mm long; lamina elliptic, lanceolate or ovate, margins denticulate to weakly crenate with 4–34 teeth per side of midrib"	21
21	"Extrafloral nectaries stipitate"	"Croton verreauxii"
21	"Extrafloral nectaries sessile"	22
22	"Stipules 0.5–1 mm long; extrafloral nectaries 0.8–1.2 mm long; leaf lamina below with scattered peltate trichomes"	"Croton choristadenius"
22	"Stipules 1–4 mm long; extrafloral nectaries 0.4–0.6 mm long; leaf lamina below with scattered peltate scales"	"Croton acronychioides"
23	"Leaf lamina with dense velutinous indumentum below"	24
23	"Leaf lamina with scattered to sparse indumentum below"	26
24	"Leaf indumentum yellow; extrafloral nectaries stipitate"	"Croton densivestitus"
24	"Leaf indumentum orange-brown or ferruginous-silver; extrafloral nectaries sessile"	25
25	"Leaf indumentum orange-brown; stipules lanceolate, 3–6 mm long; inflorescence bracts linear-lanceolate"	"Croton stockeri"
25	"Leaf indumentum ferruginous-silver; stipules subulate, 0.3–0.9 mm long; inflorescence bracts lanceolate to oblanceolate"	"Croton magneticus"
26	"Leaf lamina with 70–112 teeth"	"Croton habrophyllus"
26	"Leaf lamina with 18–64 teeth"	27
27	"Leaf indumentum uncoloured to silver"	28
27	"Leaf indumentum ferruginous to yellow"	29
28	"Leaf lamina with 40–56 teeth, extrafloral nectaries stipitate; fruits globose, c. 4 mm long and 4 mm diameter"	"Croton dockrillii"
28	"Leaf lamina with 18–34 teeth, extrafloral nectaries sessile; fruits depressed-globose, 4–5 mm long, 6–7 mm diameter"	"Croton mutabilis"
29	"Stipules lanceolate, 4–4.5 mm long; male flower sepals 1.6–2 mm long"	"Croton triacros"
29	"Stipules linear to linear-lanceolate, 0.7–3.9 mm long; male flower sepals 2–2.5 mm long"	30
30	"Male flower pedicels 1–2 mm long, sepals obovate; styles bifid; fruits globose, 4–5 mm long, 4–4.5 mm diameter"	"Croton rarus"
30	"Male flower pedicels 2.5–7 mm long, sepals ovate; styles multifid, divided twice; fruits depressed-globose, 4.5–5 mm long, 6–7 mm diameter"	"Croton byrnesii"