Dungon - Origin of the Placename - A Theory

A Dungon tree specimen, Heritiera sylvatica S.Vidal,
First published in Revis. Pl. Vasc. Filip.: 66 (1886) [1] 

One possible origin of the name Dungon may be the abundance of Dungon tree, scientific name: Heritiera sylvatica[1], in the region as this type of tree can be found in forests at low and medium altitudes.

Dungon is "a large tree measuring up to 45 meters in height and 100 centimeters in diameter. It is slightly fluted at the base and has buttresses. Its outer bark is light brown and flaky...The leaves are simple, alternate, and oblong-elliptic to ovate. Each leaf measures 15 x 4-6 centimeters, with the base that is subacute to rounded."[2]

"Due to the toughness of the wood, it is favored for bulletproof shields", this tree is "recommended for steamed bent work where strength and durability are required".[2]

In the construction and outfitting of the boats for the Balangay Expedition in 2009, it was reported that the team sourced this type of trees from the Eastern region of Tawi-Tawi [3], the area where Dungon the historical place is situated.

References:
[1] Heritiera sylvatica S.Vidal, first published in Revis. Pl. Vasc. Filip.: 66 (1886) - https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:823591-1

[2] "Tree of the month (part 1): Dungon, Heritiera Sylvatica" (2013) - https://www.philstar.com/the-freeman/cebu-news/2013/03/12/918699/tree-month-part-1-dungon 

[3] http://www.sail-world.com/Ancient-Balangay-sailing-vessel-sets-out-on-four-year-saga/58368 and https://groups.google.com/forum/#!topic/soc.culture.filipino/ud8_tCfLjqU