The Great Barrier Reef
164
5. Flower larger than 5 cm, seed pod long curved ....................... Dolichandrone spathacea
– Flower less than 1 cm, seed pod rounded, compact ....................................................6
6. Seed pod rugose (bivalved, pubescent, irregular), leaflet tip imarginate, buttresses
or pneumatophores absent ........................................................................ Cynometra iripa
– Seed pod smooth (obscurely 4-valved, coriaceous, globate), leaflet tip apiculate,
with conical pneumatophores or plank buttresses ....................... Xylocarpus (2 taxa)
7. Simple opposite leaves ........................................................................................................8
– Simple alternate leaves ...................................................................................................16
8. Leaf undersurface pubescent (silvery grey appearance) .................................................
............................................................................. Avicennia marina (2 varieties) (Fig. 16.3)
– Leaf undersurface not pubescent ...................................................................................9
9. Flower zygomorphic, leaf often spiny (small shrub to 2 m) ..............Acanthus (2 taxa)
– Flower symmetric, leaf never spiny (shrub or tree) ...................................................10
10. Prop roots and/or buttresses, fruit germinates on tree, viviparous (long, >6 cm,
green) ...................................................................................................................................11
– Prop roots or buttresses absent, fruit with seeds, not viviparous (rounded, <6 cm,
often not green) ...............................................................................................................13
11. Fruit inverted pear-shaped, calyx lobes less than six (flat-expanded tube) ..............12
– Fruit within calyx, calyx lobes 8–15 (turbinate tube) ...................... Bruguiera (6 taxa)
12. Calyx lobes five (thick sinuous buttresses) ............................................. Ceriops (3 taxa)
– Calyx lobes four (sturdy prop roots) ............................................... Rhizophora (4 taxa)
13. Stipules persistent, pod deeply 8-ribbed (barrel-like) ......... Scyphiphora hydrophylacea
– Stipules absent, pod or fruit not deeply ribbed ..........................................................14
14. Fruit to 4 cm (globular), tree medium to large (leaves large >5 cm), pneumatophores
present ..................................................................................................... Sonneratia (4 taxa)
– Fruit less than 1 cm (calyx pod), shrub to small tree (leaves small <2 cm),
pneumatophores absent .................................................................................................15
15. Leaf smooth (glabrous) with oil glands (aromatic when crushed), flower petals
absent .....................................................................................Osbornia octodonta (Fig. 16.8)
– Leaf pubescent without oil glands, flower petals conspicuous ........ Pemphis acidula
16. Leaf undersurface pubescent (hairs or fine scales, silvery appearance) ....................17
– Leaf undersurface not pubescent (glabrous) ..............................................................18
17. Leaf flat, less than 12 cm, seed pod ovate, scaly (less than 1 cm) ...................................
...........................................................................................................Camptostemon schultzii
– Leaf floppy, greater than 12 cm, seed pod keeled, smooth (greater than 5 cm).........
................................................................................................................. Heritiera littoralis
18. Leaf petiole envelopes stem (leaving annular scars) .........................Aegialitis annulata
– Leaf petiole does not envelop stem ..............................................................................19
164
5. Flower larger than 5 cm, seed pod long curved ....................... Dolichandrone spathacea
– Flower less than 1 cm, seed pod rounded, compact ....................................................6
6. Seed pod rugose (bivalved, pubescent, irregular), leaflet tip imarginate, buttresses
or pneumatophores absent ........................................................................ Cynometra iripa
– Seed pod smooth (obscurely 4-valved, coriaceous, globate), leaflet tip apiculate,
with conical pneumatophores or plank buttresses ....................... Xylocarpus (2 taxa)
7. Simple opposite leaves ........................................................................................................8
– Simple alternate leaves ...................................................................................................16
8. Leaf undersurface pubescent (silvery grey appearance) .................................................
............................................................................. Avicennia marina (2 varieties) (Fig. 16.3)
– Leaf undersurface not pubescent ...................................................................................9
9. Flower zygomorphic, leaf often spiny (small shrub to 2 m) ..............Acanthus (2 taxa)
– Flower symmetric, leaf never spiny (shrub or tree) ...................................................10
10. Prop roots and/or buttresses, fruit germinates on tree, viviparous (long, >6 cm,
green) ...................................................................................................................................11
– Prop roots or buttresses absent, fruit with seeds, not viviparous (rounded, <6 cm,
often not green) ...............................................................................................................13
11. Fruit inverted pear-shaped, calyx lobes less than six (flat-expanded tube) ..............12
– Fruit within calyx, calyx lobes 8–15 (turbinate tube) ...................... Bruguiera (6 taxa)
12. Calyx lobes five (thick sinuous buttresses) ............................................. Ceriops (3 taxa)
– Calyx lobes four (sturdy prop roots) ............................................... Rhizophora (4 taxa)
13. Stipules persistent, pod deeply 8-ribbed (barrel-like) ......... Scyphiphora hydrophylacea
– Stipules absent, pod or fruit not deeply ribbed ..........................................................14
14. Fruit to 4 cm (globular), tree medium to large (leaves large >5 cm), pneumatophores
present ..................................................................................................... Sonneratia (4 taxa)
– Fruit less than 1 cm (calyx pod), shrub to small tree (leaves small <2 cm),
pneumatophores absent .................................................................................................15
15. Leaf smooth (glabrous) with oil glands (aromatic when crushed), flower petals
absent .....................................................................................Osbornia octodonta (Fig. 16.8)
– Leaf pubescent without oil glands, flower petals conspicuous ........ Pemphis acidula
16. Leaf undersurface pubescent (hairs or fine scales, silvery appearance) ....................17
– Leaf undersurface not pubescent (glabrous) ..............................................................18
17. Leaf flat, less than 12 cm, seed pod ovate, scaly (less than 1 cm) ...................................
...........................................................................................................Camptostemon schultzii
– Leaf floppy, greater than 12 cm, seed pod keeled, smooth (greater than 5 cm).........
................................................................................................................. Heritiera littoralis
18. Leaf petiole envelopes stem (leaving annular scars) .........................Aegialitis annulata
– Leaf petiole does not envelop stem ..............................................................................19