Lichen is mostly found attached to the bark of tree trunks. Local Fruit Park in the Rambai Mangrove Centre area is an area consisting of lowlands and some mangrove areas that are muddy and experiencing tides. The purpose of this research is to find out what types of lichens are in the Rambai Mangrove Centre Local Fruit Park. As well as to describe the suitability, feasibility, readability and response to the E-Booklet developed as supporting material for the Cryptogamae (Botany of Lower Plants) course. The research used a descriptive approach to the research of crustose lichen species in the Local Fruit Park of the Rambai Center Mangrove area with a roaming data collection technique. The development of the 4-D model was determined as an electronic booklet development model. This development will go through several stages, namely suitability testing, feasibility, readability and student response using the 4-D Development model (Four D). The results showed that 8 species of lichen were found in the Rambai Centre Mangrove Area Local Fruit Park. The developed lichen electronic booklet obtained a suitability value of 4.47 which is classified as very suitable, obtained a feasibility value of 4.47 which is classified as very feasible, obtained a readability value of 89.6% which is classified as very good and obtained a student response value of 90% which is classified as very positive