Relationships between floral morphology and pollinator fauna in insular and main island populations of Hosta longipes ( L iliaceae)

We compared the floral morphologies and pollinator fauna and morphologies of Hosta longipes var. longipes on the main J apanese island of H onshu and var. latifolia on the I zu I slands to examine the differentiation processes of H. longipes in the island system. The corolla length was shorter on the southern I zu I slands than on the main island and northern I zu I slands. However, the size of other flower parts of H. longipes did not simply decrease across main island H onshu and the I zu I slands, unlike other I zu endemic plant species studied previously. Instead, the floral morphology showed a complicated variation pattern. Pollinator fauna of H. longipes on the I zu I slands varied more widely than those on the main island. The diverse pollinator fauna may have influenced the morphological differentiation of H. longipes on these islands.