Are you into symbolism of posts and pillars? I'm hoping for comments to suggest further inquiry.

Although Australia is said to have been virginal and isolated for 30,000 years, maybe it was not..
"The Palmyra tree is the official tree of Tamil Nadu.  Palakkad District of Kerala State is popularly known as " land of Palmyra trees" . Palmyra trees are known as the icon of this district and has a vast cultural, heritage and literary association. The black timber is hard, heavy, and durable and highly valued for construction, especially in structures exposed to water, such as wharves, fences and boats.
Kerala comes from 'kera' in Malayalam, which translates to coconut,  so " land of coconut."
In Indonesia the Palmyra tree is the symbol of South Sulawesi province and used for  thatching . East Indonesia's lontar palm [Borassus sundaicus] has been called the “tree of life” . The wood of the trunk is used for tools and housing. The leaves are used for thatch."


There are 2 countries in Australia that seem to be named for Bengal's bungalow houses with palm-tree thatch.  Both peoples say a boat arrived .  Bundjalung is near Brisbane and Tharawal is near Sydney.  Indonesian banglo is "bungalow" and banjar are palm-thatched banglos for local government. 

 Bundjalung bandja-   "cover, enclose " . : Ngay bandjani gala waybar bagulu. ‘I covered my house with bark '.
bunjala shut ,enclose.
bagul  bark (of tree) .
bandjam. banggam  Cabbage Tree Palm  banjam bandjan  piccabeen palm.
banggalu  a palm tree (Bangalow palm?); 
banggi   camp site .
ban.gin  temporary  shelter. made from grass; cf bangil. "grass"

Bangalow palm tree in Tharawal / Darawal.
Uses : water carrier, thatching for shelter,   ".
bangala   " water-carrying vessel made from bark tied at each end".

"They believe their  ancestors introduced this plant to east Australia when they first arrived in a large canoe . . . They brought the Dharawal or Cabbage Tree Palm with them from the north and the people are named for this sacred tree ."

Old Javanese dāru (Sanskrit) "piece of wood, timber".
taraṅ roofing of woven palm-leaf
taruwara (Skt) best of trees.
tarab* taraban, shed, shelter, pavilion
-wala In compounds ``all kinds of, in every respect'' .

" Nepal India   architecture... makara as guardian of gateways,  the curved prongs of the vast crossed-vajra that encompasses the four gateways of the two-dimensional mandala. Of the three dimensional-mandala this crossed-vajra supports the whole structure of the mandala palace symbolizing the immovable stability of the vajra-ground on which it stands."     "The temples of ancient Java are notable with the application of makara as both decorative and symbolic elements of temple architecture".

"Towards a Fijian Theology of Place  ...  This is the communal request for the blessings of the gods (or ancestors) on the newly installed chief or chief guest, according to the occasion. ... Men were killed to be buried under corner posts when an important house such as the chief's was built . "

A makara pillar , fossil tree trunks which held up the sky , is held in south Australia museum.  Probably Greek and Egyptian temple columns were palm trees. They had acanthus capitals such as Skt Bana acanthus tree. .Bangalore  / Bengalaru state India, may be Benga tree . In Goa India,   banglo  means "palace" .Tamil bangla "bungalow" ,   banai  "palm tree" . Skt bundira "house".


So this may be the background for a country being named Tharawal "palm tree."