1	"Leaves and stems covered with glandular hairs 0.1–0.3 mm long"	"Prostanthera cryptandroides subsp. euphrasioides"
1	"Leaves and stems glabrous or with simple hairs and surface glands but no glandular hairs"	2
2	"Leaf blades with margins lobed or toothed"	3
2	"Leaf blades with margins entire"	7
3	"Leaf blades with 5–16 pairs of teeth; petioles 5–12 mm long"	"Prostanthera rupicola"
3	"Leaf blades with 1–5 pairs of teeth; petioles 0.5–6 mm long"	4
4	"Leaf blades pubescent above and below with erect, straight hairs 0.1–0.3 mm, margins with 2–4 pairs of teeth 0.3–0.8 mm long"	"Prostanthera albohirta"
4	"Leaf blades mostly glabrous or with pubescence on midrib above or below, margins with 1–5 pairs of teeth 0.5–1.5 mm long"	5
5	"Petioles 0.5–1 mm long; branchlets densely pubescent with erect, straight hairs 0.4–0.6 mm long; leaf blades with 1 pair of teeth 0.8–1.5 mm long"	"Prostanthera athertoniana"
5	"Petioles 1.5–10 mm long; branchlets moderately to sparsely pubescent with appressed, curved and/or straight hairs 0.05–2 mm long or glabrous; leaf blades with 1–5 pairs of teeth up to 1 mm long"	6
6	"Leaf blade margins flat with 1–5 pairs of usually obtuse teeth to 1 mm long; leaf blades 0.7–4 cm long, 0.4–1.1 cm wide; branchlets with curved erect hairs"	"Prostanthera ovalifolia"
6	"Leaf blade margins recurved for c. 1 mm with 2–5 pairs of triangular acute teeth to 0.5 mm long; leaf blades 3–7 cm long, 0.8–2 cm wide; branchlets glabrous or with sparse straight and antrorse hairs"	"Prostanthera eungella"
7	"Leaf blades with tomentum below, or above and below"	8
7	"Leaf blades glabrous or with a few hairs along midrib above or below"	19
8	"Leaves and stems covered with dense pubescence of compact crisped hairs 0.1–0.5 mm long"	9
8	"Leaves and stems with straight or curved, erect, ascending or appressed hairs, not densely compact"	10
9	"Leaf blades ovate to oblong, length: width ratio 1.5–4: 1, 4–20 mm long, 2–7 mm wide; flowers 7–11 mm long"	"Prostanthera collina"
9	"Leaf blades orbicular to ovate, length: width ratio 1–2: 1, 5–13 mm long, 3.5–9 mm wide; flowers 11–15 mm long"	"Prostanthera suborbicularis"
10	"Leaf blades recurved or revolute"	11
10	"Leaf blades flat, involute or incurved"	14
11	"Leaf blades densely pubescent below, hairs erect, curled, curved and straight, 0.1–0.5 mm long"	"Prostanthera granitica"
11	"Leaf blades sparsely pubescent or puberulent below, hairs erect, straight or antrorse, 0.05–0.3 mm long"	12
12	"Flowers in terminal botryoids; leaf blades linear"	"Prostanthera sp. (Dunmore D.M.Gordon  8A)"
12	"Flowers solitary in leaf axils; leaf blades ovate to narrowly ovate or oblong"	13
13	"Calyces puberulent inside, 2.6–3.4 mm long; floral bracteoles 1.2–2 mm long, 0.2–0.3 mm wide"	"Prostanthera sp. (Baking Board V.Hando 135)"
13	"Calyces glabrous or with sparse hairs inside, 4.5–5 mm long; floral bracteoles 3.5–4 mm long, 0.5–0.6 mm wide"	"Prostanthera parvifolia"
14	"Leaf blades orbicular, 2.5–5 mm long; calyces 15–20 mm long"	"Prostanthera megacalyx"
14	"Leaf blades linear, oblong, obovate or narrowly elliptic, 8–50 mm long; calyces 4–12 mm long"	15
15	"Leaf blades involute or incurved, linear, length: width ratio 10–30: 1"	"Prostanthera sp. (Gilbert River M.D.Godwin + C4040)"
15	"Leaf blades flat, oblong, obovate, narrowly obovate or elliptic, length: width ratio 1.7–6.5: 1"	16
16	"Leaf blades obovate, length: width ratio 1.7–2: 1"	"Prostanthera tozerana"
16	"Leaf blades narrowly obovate, oblong or narrowly elliptic, length: width 3–6.5: 1"	17
17	"Leaf blade hairs erect or ascending and antrorse; calyx lobes equal in length"	"Prostanthera lithospermoides"
17	"Leaf blade hairs antrorse and usually appressed; calyx lobes unequal in length"	18
18	"Branchlets moderately hairy with appressed, white hairs (0.25–) 0.6–0.9 mm long; petioles 2.5–4 mm long; floral bracteoles 0.3–0.5 mm wide"	"Prostanthera clotteniana"
18	"Branchlets very densely hairy with appressed, white hairs 0.2–0.5 mm long; petioles 4–5 mm long; floral bracteoles 0.8–1.2 mm wide"	"Prostanthera mulliganensis"
19	"Leaf blades flat, conduplicate or involute"	20
19	"Leaf blades recurved or revolute"	25
20	"Branchlets with appressed antrorse hairs"	21
20	"Branchlets with curved antrorse or straight erect hairs"	22
21	"Leaf blades linear, 10–50 mm long; corollas 14–18 mm long; calyces 5–8 mm long"	"Prostanthera nivea"
21	"Leaf blades oblong to ovate-lanceolate, 3–15 mm long; corollas 7-10 mm long; calyces 3–4 mm long"	"Prostanthera saxicola var. major"
22	"Leaf blades spathulate; branchlet hairs in 2 narrow zones between leaf nodes, erect, curved, antrorse, 0.3–0.8 mm long"	"Prostanthera spathulata"
22	"Leaf blades not spathulate, ovate, obovate or linear; branchlets hairs evenly spread or clustered at leaf nodes, erect, straight or curved and antrorse, 0.1–0.4 mm long"	23
23	"Leaf blades 28–85 mm long, 10–25 mm wide; calyx tubes 4.5–6 mm long, upper lobes 2.5–3.3 mm long"	"Prostanthera petraea"
23	"Leaf blades 6–25 mm long, 1–10 mm wide; calyx tubes 1–5 mm long, upper lobes 0.5–3 mm long"	24
24	"Flowers in botryoids; calyx tubes 1–2 mm long, upper lobes 0.5–1.5 mm long"	"Prostanthera ovalifolia"
24	"Flowers single in leaf axils; calyx tubes 4–5 mm long, upper lobes 2–3 mm long"	"Prostanthera ringens"
25	"Leaf blades linear, often curved"	26
25	"Leaf blades ovate, narrowly elliptic or narrowly obovate, straight"	27
26	"Branchlets glabrous except for hairs at leaf nodes; leaf blades with margin recurved for c. 1 mm, apices obtuse, 10–45 mm long; inflorescence a terminal leafy botryoid; corollas white, tubes often with pinkish mauve tinge"	"Prostanthera linearis"
26	"Branchlets with white appressed antrorse hairs 0.1–0.4 mm long; leaf blades revolute or recurved, apices acute, 6–25 mm long; flowers single in leaf axils; corollas pale to deep mauve or purple"	"Prostanthera scutellarioides"
27	"Leaf blades 4–8 (–12) mm long, 1.5–3 mm wide; flowers solitary in leaf axils"	"Prostanthera parvifolia"
27	"Leaf blades 16–85 mm long, 2–25 mm wide; flowers in a terminal botryoid"	28
28	"Branchlets glabrous; leaf blades narrowly elliptic, oblong or narrowly obovate, 16–38 mm long, 2–10 mm wide, lateral veins obscure; petioles 1–3 mm long; corollas mauve with purple to dark mauve dots on throat"	"Prostanthera oleoides"
28	"Branchlets moderately to densely hairy, hairs ± curved, antrorse, white, 0.5–1 mm long; leaf blades ovate, 28–85 mm long, 10–25 mm wide, lateral veins 1–3 pairs, raised below; petioles 4–16 mm long; corollas white"	"Prostanthera petraea"