1	"Flowers solitary"	2
1	"Inflorescence 2–5-flowered, rarely 1"	5
2	"Petals without a central spine or spine minute, c. 0.2 mm long"	"Bruguiera exaristata"
2	"Petals with a central spine, > 3 mm long"	3
3	"Petals without apical bristles or bristles minute, c. 0.3 mm long"	"Bruguiera sexangula"
3	"Petals with apical bristles, > 1 mm long"	4
4	"Petal lobes with 3–4 bristles; bristles > 2 mm long"	"Bruguiera gymnorhiza"
4	"Petal lobes with 1–2 bristles; bristles < 2 mm long"	"Bruguiera × rhynchopetala"
5	"Mature flower buds 18–22 mm long, 9–11 calyx lobes"	"Bruguiera hainesii"
5	"Mature flower buds 10–15 mm long, 8 calyx lobes"	6
6	"Calyx lobes stout 2–3 mm long; fruit calyx lobes adpressed against hypocotyl"	"Bruguiera parviflora"
6	"Calyx lobes elongate 4–6 mm long; fruit calyx lobes reflexed at right angles to the hypocotyl"	"Bruguiera cylindrica"