1. Leaves glabrous or hispid with bulbose, scattered hairs;	2
1. Leaves villous or pubescent;	7
2. Petals white; siliqua laterally compressed;	B. insularis
2. Petals yellow; siliqua isodiametric or dorsally compressed;	3
3. Leaf teeth obtuse; siliqua navicular isodiametric, 25–40 mm × 8–12 mm; valves thickened, spongy, dorsally smooth; rostrum widely conic, 10–15 mm, 1–2-seeded;	B. macrocarpa
3. Leaf teeth acute; siliqua linear, 25–70 mm × 3–7 mm; valves thin, dorsally ribbed; rostrum subulate to narrowly conic, 4–11 mm, seedless;	4
4. Petals pale yellow, 13–20 mm × 5–8 mm; siliqua 25–45(–50) mm × 5–7.5 mm;	5
4. Petals yellow, 18–27 mm × 7–13 mm; siliqua 35–70 mm × 3–4.5 mm;	6
5. Petals 14–20 mm × 5–7 mm; fruiting pedicels 10–18 mm, siliqua tetragonous, laterally compressed, 35–45(–50) mm × 6–7.5 mm; seed diameter 2.85–3.2 mm;	B. villosa subsp. brevisiliqua
5. Petals 13–18 mm × 6.5–8 mm; fruiting pedicels 16–26 mm, siliqua almost isodiametric, slightly compressed, (20)–25–35(–40) mm × 5–6 mm; seed diameter 2.3–2.5 mm;	B. tardarae
6. Leaves green, glabrous; leaf lamina ovate–lanceolate, acute, deeply incised, margin loosely dentate;	B. rupestris subsp. rupestris
6. Leaves with hispid hairs, mainly in upper blade; leaf lamina ovate–elliptical, obtuse, lobed, margin minutely dentate;	B. rupestris subsp. hispida
7. Ovary hairy; fruit corpus hairy, subglobose to ellipsoid, smooth, thickened, spongy, 8−18 × 8−11 mm;	B. trichocarpa
7. Ovary glabrous; fruit corpus glabrous, linear–cylindrical, torulose, thin, 25−100 × 36.5 mm;	8
8. Petiole auriculate at the base, up to 15(18) mm;	9
8. Petiole not auriculate, up to 30 mm;	10
9. Pedicels hairy, 14–35 mm; petals yellow; siliqua 60–100 mm × 3–5 mm, not ribbed dorsally; rostrum 10–20 mm; fruiting pedicels 25–35 mm;	B. incana subsp. incana
9. Pedicels glabrous, 7–12 mm; petals white; siliqua 30–65 mm × 2.5–3 mm, ribbed dorsally; rostrum 4–10 mm; fruiting pedicels 14–20 mm;	B. incana subsp. raimondoi
10. Leaf lamina lyrate, margin crispate–denticulate; petiole winged; siliqua 30–45 mm × 5–6.5 mm;	B. villosa subsp. drepanensis
10. Leaf lamina lobed, margin dentate, petiole unwinged; siliqua 3–5 mm wide;	11
11. Leaf lamina minutely dentate; siliqua laterally compressed, 25–35 × 4–5 mm;	B. villosa subsp. tineoi
11. Leaf lamina broadly dentate; siliqua not laterally compressed, 30–75 mm × 3–5 mm;	12
12. Leaf margin crenate–dentate; sepals 12–15 mm; petals 24–26mm; siliqua 30–60 mm × 4–4.5 mm, dorsally ribbed;	B. villosa subsp. villosa
12. Leaf margin irregularly dentate; sepals 8–11 mm; petal 16–22 mm; siliqua 45–75 mm × (3–)3.5–3.8 mm, dorsally not ribbed.	B. villosa subsp. bivonana