16 – Mangroves and Seagrasses
163
Figure 16.7 Unusually exposed twisty roots of milky mangrove, Excoecaria agallocha, at Flying Fish Point at the
mouth of the Johnstone River. (Photo: N. Duke.)
(A)
(B)
Figure 16.8 A, Shrubs of myrtle mangrove, Osbornia
octodonta, growing on an exposed sandy foreshore north
of Agnes Waters. B, A shrubby hedge of myrtle mangrove,
Osbornia octodonta, growing at the mouth of Coopers
Creek north of the Daintree. (Photos: N. Duke.)
N KEY TO THE 39 MANGROVES OF THE GBR CATCHMENT COAST
1. Palm or ground fern, both trunkless .................................................................................2
– Shrub or tree ......................................................................................................................3
2. Palm to 10 m .................................................................................................. Nypa fruticans
– Ground fern to 1 m ...................................................................... Acrostichum speciosum
3. Exuding white sap (oozes from broken leaf or cut bark) .................................................
.............................................................................................. Excoecaria agallocha (Fig. 16.7)
– No exuding sap .................................................................................................................4
4. Compound leaves ................................................................................................................5
– Simple leaves .....................................................................................................................7