Dillenia spp. of the family Rubiaceae, including at least D. alata, D. albiflos, D. borneensis, D. excelsa, D. grandifolia, D. hainensis, D. indica, D. luzoniensis, D. meliosmaefolia, D. obovata, D. pentagyna, D. pulchella, D. reticulata, D. salomonensis, D. speciosa, and D. suffruticosa
An Asian wood, primarily from Idonesia and Malaysia but also India and China
I have no familiarity with this wood and no idea the extent of variation amoung the various Dillenia species that are sold with this common name.
web pics:
planks
plank with wet and dry areas and a slight closeup of the wet area
turned pen blank, moistened
pen blanks, cut on a bias and moistened for the pic