7. Floristic Status of Palawan in 1982

A study of the flora of Palawan had to start with the production of lists of the species already collected on the island. Lists were compiled for the very first time 1982:

1. A list of collectors, 1870 - 1981
2. A preliminary check-list of Gymnosperms
3.  A preliminary check-list of Monocotyledons. 
4. A preliminary check-list of  Dicotyledons. 
5. A preliminary check-list of Pteridophyta.

Some very surprising and unexpected facts were revealed by this study. Mapping the areas visited by collectors illustrated the starting fact that the entire northern third of mainland Palawan, including the island's only lake, had never been collected botanically. In addition, even though Balabac Isand has been visited many times, Bugsuk Island was unexplored. Further, the western slopes of Mt. Mantalingajan and Mt. Victoria were also uncollected.

Generally, most collection has been professional. It is puzzling that a large number of genera which occur in Borneo and Luzon, are not known from the Palawan region.Additionally, an unusually low number of tree genera and species have been recorded. Whether this is a result of real absence, or is due to biased or under-collecting was then unknown. Only further exploration could reveal the answer.

The degree of under-collecting was illustrated the number of specimens collected for each species. An investigation of the Dipterocarpaceae and the genus Myristica (normally common forest trees) revealed that they were represented by mostly less than 10 collections per species. Endemics were rare and known from 1 - 3 collections.

A 15.5% endemism figure for Palawan was calculated, based on the work of Merrill (Table below). Recent research on the entire SE Asian flora (Flora Malesiana) had effected Merrill's work in three ways. Firstly, species which were thought to be endemic have been found to be widespread, e.g. Quercus merrillii, a former endemic to Palawan, is now known to be one of the more widespread Bornean species in the genus. Other species described before Merrill's enumeration and cited by him, were in fact redescriptions of already known species (every species of Rinorea quoted by Merrill is an example of this). Finally new species, either new to science or just to Palawan, have been added through exploration.

The result was that the total number of species has remained fairly static and considerable numbers of name changes have occurred. The endemism figure for those genera covered by modern revisions was then 4.7%. This indicates that the entire flora was somewhat less unique than previously suggested.

Exploration is essential if the island's true flora is to be described. The current status of knowledge was restricted to those small areas already collected while the greater part of the island was unknown territory.