1	"Fruits 20-25 mm diameter; calyx 16-30-ribbed"	"Sida platycalyx"
1	"Fruits 2-11 mm diameter; calyx 5-10-ribbed or unribbed"	2
2	"Calyx tube 10-ribbed"	3
2	"Calyx unribbed or with a few irregular ribs"	10
3	"Leaf lower surface with sparse stellate hairs (hairs not overlapping)"	4
3	"Leaf lower surface with dense or very dense stellate hairs"	5
4	"Mericarps with apical awns; fruits 4-5 mm across"	"Sida acuta"
4	"Mericarps without apical awns; fruits 2-3 mm across"	"Sida pusilla"
5	"Stellate hairs on branchlets 0.1-0.4 mm across, indumentum “smooth” or velvety to the naked eye"	6
5	"Stellate hairs on branchlets 0.6-1.2 mm across, indumentum “rough” or uneven to the naked eye"	8
6	"Mericarps 5"	"Sida spinosa"
6	"Mericarps 9-11"	7
7	"Basal one-third of lamina +/- entire; pedicels 16-30 mm at anthesis; leaves 2-3.5 times longer than wide"	"Sida rhombifolia"
7	"Marginal teeth extending to base of lamina; pedicels 5-15(-30) mm at anthesis; leaves 3-5 times longer than wide"	"Sida rohlenae"
8	"Leaves broadly-ovate, 1.5-1.7 times longer than wide; mericarps 8-10"	"Sida cordifolia"
8	"Leaves elliptical to ovate, 2-5 times longer than wide; mericarps 5-8"	9
9	"Mericarp awns present; long simple hairs frequently present on branchlets"	"Sida atherophora"
9	"Mericarp awns absent; long simple hairs absent from branchlets"	"Sida magnifica"
10	"Calyx completely enclosing flower and fruit"	"Sida cleisocalyx"
10	"Calyx not enclosing flower or fruit"	11
11	"Flowers solitary in leaf axils"	12
11	"Flowers/fruits not solitary in leaf axils (inflorescence may be terminal, or cymose, or in umbelliform clusters)"	32
12	"Indumentum comprising fimbriate scales"	13
12	"Indumentum predominantly stellate hairs, scales absent"	14
13	"Scales 0.25-0.4 mm diameter; leaves 12-15 times longer than wide; mericarps 5 per fruit"	"Sida argentea"
13	"Scales 0.5-0.6 mm diameter; leaves 2-4 times longer than wide; mericarps 11-12 per fruit"	"Sida spenceriana"
14	"Calyx and/or pedicel with few to many simple glandular hairs mixed in with the stellate hairs"	15
14	"Calyx and pedicel with stellate hairs only"	17
15	"Lower leaf surface densely to very densely hairy (stellate hairs overlapping)"	"Sida sp. (Aramac E.J. Thompson+ JER192)"
15	"Lower leaf surface sparsely hairy (stellate hairs not overlapping)"	16
16	"Mericarps 8-9, each with a prominent radial wing; stellate hairs on branchlets 0.3-0.5 mm wide"	"Sida goniocarpa"
16	"Mericarps 6-7, radial wings absent; stellate hairs on branchlets 0.2-0.3 mm wide"	"Sida trichopoda"
17	"Leaf base cordate"	18
17	"Leaf base cuneate to obtuse"	24
18	"Mericarps 14-18 per fruit"	"Sida aprica"
18	"Mericarps 5-11 per fruit"	19
19	"Pedicels 14-33 mm long at anthesis"	20
19	"Pedicels 2-15 mm long at anthesis"	22
20	"Mericarps 6-7"	"Sida macropoda"
20	"Mericarps 8-10"	21
21	"Erect shrub, fruits 5-6 mm wide"	"Sida sp. (Musselbrook M.B. Thomas+ MRS437)"
21	"Prostrate or sprawling shrub, fruits 6-7 mm wide"	"Sida sp. (Charters Towers E.J. Thompson+ CHA456)"
22	"Fruits 4-5 mm diameter; mericarps 5-6, glabrous"	"Sida sp. (Gordonbrook Station E.J. Thompson+ MUT46)"
22	"Fruits 5-7 mm diameter; mericarps 7-11, hairy"	23
23	"Pedicel articulation absent; stellate hairs 0.8-1.3 mm across; mericarps 7-8"	"Sida corrugata"
23	"Pedicel articulation present; stellate hairs 0.4-0.9 mm across; mericarps 8-11"	"Sida brachypoda"
24	"Pedicels 0.5-7 mm long at anthesis"	25
24	"Pedicels 8-65 mm long at anthesis"	27
25	"Leaves tiny, no more than 7.5 mm long"	"Sida intricata"
25	"Larger leaves 10-50 mm long"	26
26	"Leaves very broad (0.8-1.2 times longer than wide), hairs not obscuring lower leaf surface; mericarps hairy"	"Sida everistiana"
26	"Leaves narrow (2.5-9 times longer than wide), hairs completely obscuring lower leaf surface; mericarps glabrous"	"Sida ammophila"
27	"Stellate hairs sparse on underside of leaf (hairs not overlapping)"	28
27	"Stellate hairs very dense on underside of leaf (hairs obscuring leaf surface)"	29
28	"Stellate hairs 0.2-0.3 mm across; mericarps hairy; pedicels 21-28 mm long at anthesis"	"Sida laevis"
28	"Stellate hairs 0.3-0.9 mm across; mericarps glabrous; pedicels 25-65 mm long at anthesis"	"Sida sp. (Laglan Station L.S. Smith 10325)"
29	"Stellate hairs 0.8-1.1 mm across; mericarps very sparsely hairy"	"Sida sp. (Murray Springs R.W. Johnson+ MRS919)"
29	"Stellate hairs 0.3-0.5 mm across; mericarps glabrous or conspicuously hairy"	30
30	"Leaves 4.3-7 times longer than wide; articulation on lower half of pedicel; calyces dark grey"	"Sida petrophila"
30	"Leaves 2-4 times longer than wide; articulation on upper half of pedicel; calyces green to yellow"	31
31	"Leaves 2-2.5 times longer than wide; fruits 6-8 mm across; mericarps conspicuously hairy"	"Sida asterocalyx"
31	"Leaves 3-4 times longer than wide; fruits 3-4 mm across; mericarps glabrous"	"Sida arenicola"
32	"Pedicels 0-1 mm long"	33
32	"Pedicels 1-27 mm long"	34
33	"Plants erect; leaves 50-120 mm long; inflorescences in axillary or terminal spikes; fruits 3-4 mm diameter"	"Sida hackettiana"
33	"Plants prostrate; leaves 10-20 mm long; inflorescences in short terminal cymes; fruits 4.5-5 mm diameter"	"Sida ciliaris"
34	"Flowers/fruits 2-several in umbelliform clusters, rachis 0-1 mm long"	35
34	"Flowers/fruits 2-several in axillary cymes, rachis 5-200 mm long"	38
35	"Pedicels 8-28 mm long; flowers/fruits 2 per axil"	36
35	"Pedicels 1-9 mm long; flowers/fruits several per axil"	37
36	"Stellate hairs 0.8-1.1 mm across; calyces green; mericarps very sparsely hairy"	"Sida sp. (Murray Springs R.W. Johnson+ MRS919)"
36	"Stellate hairs 0.3-0.5 mm across; calyces dark grey; mericarps conspicuously hairy"	"Sida petrophila"
37	"Plants prostrate; fruits 6-7 mm across; pedicels 3-9 mm long"	"Sida pleiantha"
37	"Plants erect; fruits 4-6 mm across; pedicels 1-3 mm long"	"Sida argillacea"
38	"Rachises dark-coloured, commonly 80-200 mm long; mericarps 9-10"	"Sida cunninghamii"
38	"Rachises pale-coloured, 5-50 mm long; mericarps 5-8"	39
39	"Fruits 3-3.5 mm diameter; leaves bright green"	"Sida sp. (Greenvale R.J. Fensham 1150)"
39	"Fruits 4-6 mm diameter; leaves grey to silvery"	40
40	"Mericarps 7-8, conspicuously hairy"	"Sida fibulifera"
40	"Mericarps 5, glabrous or very sparsely hairy"	"Sida ammophila"