One of the main purposes to continue introducing and producing high quality rubber planting materials is that the prospect of natural rubber is still encouraging, primarily due to its uses and economic viability for the manufacturing and industry purposes. This will continually improve the socio-economic status of many rubber smallholders and growers in Malaysia. As commercial planting materials, underused rubber species, including H. benthamiana and H. spruceana, have not yet been investigated. This study aims to investigate the biological features and phenotypic characteristics of the aforementioned Hevea species. Visual observation, light microscopy and scanning electron microscopy (SEM) were all utilized to assess leaf form and arrangement, petiole, leaf venation, bark surface, stomata, seed appearance, as well as laticifers. As common to all dicots, leaf venation on both H. benthamiana and H. spruceana, were arranged into a net-like pattern regarded as reticulate venation. H. benthamiana and H. spruceana both with no visible laticifers in their petioles. The bark surface observed on H. spruceana was smooth, whereas H. benthamiana exhibited deep grooves within an uneven bark surface. Both H. benthamiana and H. spruceana have a paracytic arrangement of stomata, in which each guard cell is joined by one or more secondary cells positioned along longitudinal axes that are parallel to the guard cells, and their laticifers resembled an articulated and anastomosing type within the bark. It is crucial to crossbreed different species as parent trees in order to produce new recombination that are superior in producing high yields and salient biological aspects. In future H. benthamiana and H. spruceana may serve as the solution in broadening the genetic base and producing the superior rubber planting materials in Malaysia.