We described the ectomycorrhizae (ECM) of the Japanese Lactarius section Deliciosi species L. akahatsu, L. hatsudake, L. laeticolor, and L. subindigo with the aim of promoting the use of mycorrhizae for taxonomy and expansion of available cultures. Lactarius tottoriensis (sect. Lactarius) was also included as a comparator. The ECM of the four species of sect. Deliciosi showed orange laticifers and plectenchymatous mantles, whereas those of L. tottoriensis showed white laticifers and pseudoparenchymatous mantles. The ECM of L. hatsudake and L. subindigo showed complex rhizomorphs with thicker walls and more developed vessel-like hyphae compared to the other three species. Cystidium-like cells were rarely found on the mantles of L. laeticolor and L. subindigo. Fungal cultures of the five Lactarius species from their ECM were morphologically characterized. Cultures produced laticifers on agar medium, but the five species showed different growth rates. Rhizomorphs of L. hatsudake and L. subindigo in cultures showed a similar morphology to their ECM. Molecular phylogenetic analyses of cultures from the ECM demonstrated that they were of the targeted Lactarius species and suggested the need for taxonomic studies of L. hatsudake, L. subindigo, and L. tottoriensis at the species and section levels.