Buckeye and Swallowtail

California Buckeyes are native to the interior coast ranges, and are related to chestnut trees. The name comes from the appearance of the large nuts as they emerge from their shells. The trees have evolved to tolerate the long, dry summers, and frequent droughts here. They always drop their leaves before any of the other plants, which shortens the number of weeks their big leaves aspirate moisture. But this year ended its rainfall much earlier than usual, so even as this plant is still opening blossoms, some have turned brown, and some of its leaves are yellowing in preparation to drop. This swallowtail butterfly is working against the clock to get its job of pollinating done so some nuts can form in time.