May, 1932. 
The Queensland Naturalist 
29 
of twenty feet or more, the base of the trunk is prominently 
buttressed, Bruguiera gymnorrhiza is similar in habit, but 
attains a height of about twelve feet only, and its leaves 
and flowers are smaller. Both species occur together in 
places, but B. Rheedii is the common species, and is often 
found without B. gymnorrhiza. 
Ceriops candolleana has a buttressed trunk like the 
Bruguiera s, and its roots, which run horizontally near the 
’surface, are bent up at intervals to form characteristic 
knees. It is usually found on the inner side of formations 
or in the upper parts of the tidal creeks with Avicennia 
officinalis. Sonneratia alba, a tree, attaining a height of 
thirty feet, also has spreading roots with upright processes, 
but these are in the form of stout conical pegs. This tree 
reaches its greatest development along the upper parts of 
the tidal creeks rather than along the muddy beaches. 
Avicennia officinalis, the Grey Mangrove, has a similar 
habit. Its roots run for a considerable distance just below 
the surface of the ground, sending up large numbers of 
rather slender peg roots. These shallow roots, like those 
of Ceriops, are often bared by the action of the sea. Avi- 
cennia does not extend into the sea as far as Rhizophora 
or Bruguiera Rheedii, and is more commonly found on 
the inner edge of the mangrove formations, though by no 
means always. Aegialitis annulata is a small rather fleshy 
leaved mangrove with a flared base. It grows on the edges 
of the mangrove formations. This position is compulsory, 
as the! competition in a mature mangrove forest is severe; 
the trees grow so closely that seedlings and small species 
have little chance of development. The absence of light 
is an important factor, and its effect is shown in the death 
of the lower branches which in the open normally persist. 
The line of demarcation between mangrove and strand 
is generally very sharp, and the two formations are usually 
separated by a belt of sand. Where this sandy strip does 
not, exist, the adjacent formation is usually not strand. 
Tt may be grassland, open Melaleuca leucadendron forest, 
or Eucalyptus forest; in the latter case there is a large 
admixture of Melaleuca, at least, at the edges. There is 
no invasion of the strand formation by th? mangroves. Two 
strand trees, however, are frequently found growing on 
the inner edge of the mangrove forest, and amongst them 
in tidal creeks. They are Heritiera littoralis, the Looking- 
glass Tree (recognised by its long ovate leaves, shiny dark 
green above and silvery underneath j, and Randia Fitza- 
lani, conspicuous when in frxrt because of its round fruits 
about the size of an orange. These fruits are quite inedible 
and possess a verv disagreeable taste. Both these trees 
occur in the strand, and Randia also ascends the hillsides, 
