1	"Fertile stamens 4"	2
1	"Fertile stamens 2 (sometimes accompanied by a pair of staminodes)"	13
2	"Corolla with large, 3-lobed lower lip, upper lip absent. Stamens with thick, curved bony filaments; anthers 1-celled, with stiff white hairs along sutures. [Mangrove species or cultivated escapes]"	Acanthus
2	"Corolla equally 5-lobed or 2-lipped. Stamens not with thick, bony filaments; anthers 2-celled, sutures glabrous"	3
3	"Climbers or twining herbs. Calyx entire or split into 12-20 lobes. Capsule seed-bearing at base, crowned by a long stout beak. Seed excavated on one side, large and semiglobose, 1-2 per valve, collateral"	Thunbergia
3	"Herbs or shrubs, not climbing. Calyx 4-5-lobed. Capsule not crowned by a long stout beak. Seed not excavated one side, usually flattened but if small and globular, many more than 1-2 per valve"	4
4	"Corolla more or less regular"	5
4	"Corolla 2-lipped"	12
5	"Mangrove small tree or shrub"	6
5	"Herbs or shrubs, not of mangrove habitats"	7
6	"Stigma reaching lower edge of anthers; corolla diam. mostly greater than 5 mm at anthesis; leaf blade ovate-elliptic"	"Avicennia marina subsp. marina"
6	"Stigma ±reaching upper edge of anthers; corolla diam. mostly less than 5 mm at anthesis; leaf blade lanceolate to narrowly lanceolate"	"Avicennia marina subsp. eucalyptifolia"
7	"Leaves without cystoliths, glandular hairy. Sepals 5, one longer and broader than other 4. Capsule with c. 60 small globular, glabrous seeds in 4 rows, these without hooks at their base. Upper leaves and bracts alternately arranged"	"Staurogyne: Staurogyne leptocaulis subsp. decumbens"
7	"Leaves with cystoliths, without glandular hairs. Sepals 5, more or less equal in size, or 4 in 2 unequal pairs. Capsule with 2-20 large, compressed, often hairy, seeds subtended by hooks at their base. Upper leaves and bracts opposite"	8
8	"Sepals 4, in 2 unequal pairs at right angles to each other. Capsule cone-shaped, 1-2-seeded. [Corolla lobes 5, but the lowest lobe not joined for the same length as the other four, thus giving a 2-lipped appearance]. Herbs, often spiny"	Barleria
8	"Sepals 5, more or less equal in size. Capsule with up to 20 seeds, cylindrical or club-shaped but not broadest at base. Herbs, not spiny"	9
9	"Seeds glabrous, with angular margins, 1-2 per valve. Capsule club-shaped"	"Asystasia: Asystasia gangetica subsp. gangetica"
9	"Seeds hairy, with smooth margins, more than 1-2 per valve (although all ovules not always developing in Brunoniella). Capsule club-shaped or cylindrical"	10
10	"Capsule club-shaped. Seed with hairs which rapidly expand on wetting confined to margin"	Dipteracanthus
10	"Capsule cylindrical. Seed covered all over with hairs which rapidly expand on wetting"	11
11	"Capsule with 18-26 seeds Stigma glabrous. Inflorescence axillary, long-pedunculate, often dichotomously branched, cyme. Large sprawling herb"	"Ruellia: Ruellia tuberosa"
11	"Capsule 1-6-seeded. Stigma pubescent. Inflorescence a sessile axillary cluster of single long-pedicellate flowers arising from the axils, an axillary spike, or a long-pedunculate axillary cyme arising from a basal rosette of leaves. Small herbs, often prostrate"	Brunoniella
12	"Flowers distinctly 2-lipped; lower corolla lip with long hairs and barred area. Capsule cylindrical, 8-24-seeded. Plants not spiny"	"Hygrophila: Hygrophila angustifolia"
12	"Flowers not distinctly 2-lipped; lower corolla lip without long hairs and barred area. Capsule cone-shaped, 2-4-seeded Plants spiny"	Barleria
13	"Bracts spine-tipped at apex"	14
13	"Bracts not spine-tipped at apex"	15
14	"Calyx segments 5, equal. Flowers distinctly 2-lipped. Corolla tube twisted through 180°, enclosed within a bifoliate involucre of 2 slightly unequal appressed bracts. Anther cells usually inserted at unequal levels. Capsule discoid, with a thickened rim and small apical beak. Seed glabrous, smooth or glochidiate"	Dicliptera
14	"Calyx segments 4, in unequal pairs. Flowers not distinctly 2-lipped. Corolla tube not twisted through 180°, not enclosed by 2 appressed bracts. Anther cells inserted at equal levels. Capsule conical. Seed covered with long hairs which expand on wetting"	Barleria
15	"Corolla not distinctly 2-lipped, the 5 lobes more or less equal"	16
15	"Corolla distinctly 2-lipped, the 5 lobes very unequal"	17
16	"Stamens with filaments U- or T-shaped at apex, each branch with a single anther cell at the extremity. Flowers regular, 2-5 in axillary, long-pedunculate clusters subtended by free, linear bracts. Shrubs. [Wittenoom area of Western Australia]"	Dicladanthera
16	"Stamens with filaments entire at apex, anther cells not separated laterally. Flowers somewhat irregular, in lax or dense spikes, in axillary clusters or paniculate or racemose, not subtended by a number of free linear bracts. Herbs or shrubs"	"Nelsonia: Nelsonia campestris"
17	"Anthers 1-celled. Corolla tube twisted through 180°, enclosed within a cylindrical involucre of 2 outer fused bracts with 2 smaller inner bracts fused to the outer by their midribs"	Hypoestes
17	"Anthers 2-celled. Corolla tube not twisted through 1800; not enclosed within a cylindrical involucre"	18
18	"Calyx lobes 4, with or without remnant of 5th lobe. Bracts usually noticeably white-margined or (Justicia tenella) more or less membranous with pellucid area on margin"	Rostellularia
18	"Calyx lobes 5. Bracts not noticeably white margined"	19
19	"Leaves and leaf-like bracts narrowly to very-narrowly oblong or ± linear (less often narrowly to linear-obovate or elliptic, very rarely obovate), lamina (2.8-) 6-20 times longer than broad; margin always entire. Exmouth area, Western Australia"	"Harnieria kempeana subsp. rhadinophylla"
19	"Leaves and leaf-like bracts orbicular to ovate, or elliptic to obovate or narrowly obovate, lamina 1.2-4.3 times longer than broad; margin entire, irregularly crenate or 2-5 toothed"	"Harnieria kempeana subsp. muelleri"