Penelitian pencarian agen tabir surya alami terus dikembangkan untuk mendapatkan agen tabir surya yang lebih aman. Tabir surya diperlukan untuk melindungi kulit dari bahaya sinar ultraviolet (UV). Sinar UV dapat bermanfaat bagi tubuh, namun menjadi berbahaya jika berlebih. Kemampuan suatu bahan dalam melindungi dari bahaya sinar UV biasa dinyatakan dalam sun protection factor (SPF). Penelitian ini bertujuan untuk mengetahui nilai SPF ekstrak metanol daun rambutan (Nephelium lappaceum). Penelitian ini nantinya dapat digunakan untuk menambah wawasan mengenai potensi daun rambutan untuk digunakan sebagai agen tabir surya alami. Proses ekstraksi menggunakan metode maserasi dengan pelarut metanol. Pengukuran nilai SPF dilakukan secara in vitro menggunakan metode spektrofotometri kemudian nilai absorbansi yang diperoleh dihitung menggunakan persamaan Mansur. Proses ekstraksi menghasilkan ekstrak pasta hitam kehijauan beraroma khas daun. Ekstrak metanol daun rambutan dengan konsentrasi 100, 200, 300, 400, 500, dan 1000 ppm memiliki kemampuan proteksi terhadap sinar UV, dinyatakan dalam nilai SPF berturut-turut sebesar 5,710; 10,398; 16,320; 20,920; 26,152; dan 37,983. Hasil yang berbeda dari tanaman yang sama dapat terjadi dikarenakan pengambilan bagian tubuh tanaman yang berbeda untuk diekstrak serta penggunaan jenis pelarut organik yang berbeda untuk proses ekstraksinya. Dalam penelitian ini, ekstrak metanol daun rambutan pada konsentrasi 100 dan 200 ppm memiliki kemampuan proteksi minimal, konsentrasi ekstrak 300-500 ppm memiliki kemampuan proteksi sedang, sedangkan konsentrasi ekstrak 1000 ppm memiliki kemampuan proteksi tinggi

The presence of shade trees has ecological function to reduce air pollution level. The part of leaves, stomata is responsible for the function. The study aimed to inventory species and analyze the characteristics of leaf stomata of shade trees at UIN Walisongo Semarang. This exploratory research was conducted in September-October 2021. Observation method throughout the campus area was carried out by using observation sheet. Some representative books and articles were used as references. For stomata observation, leaf samples were taken by purposive sampling. Paradermal preparations were made by wholemount method. All data were analyzed descriptively. The results showed that there were about 17 families, 37 species and 712 individual species of shade trees growing on campus 2-3. Then, there were about 8 families, 8 species and 138 individual species of shade trees growing on campus 1. The highest number of trees in both location was Glodogan Tiang. There were about 7 families, 7 species, and 194 individual species of shade trees recently planted on campus 2-3. Stomata characteristics (type, distribution, length and width, pore length and width, number, and density) differed in each species. The largest stomata size and pore were found in in abaxial leaves of Nyamplung whereas the highest stomata density was found in abaxial leaves of Mahagony. Pore size and density of stomata were related to the ability of leaves to reduce air pollution level. The shade tree data obtained in this study showed plant diversity in the campus.