Pollen development in Enkianthus perulatus (Ericaceae, Enkianthoideae) was investigated by transmission electron microscopy. Pollen grains of E. perulatus disperse as monads. The mode of deposition and dissolution of the callose wall and separation of the four microspores derived from each microspore mother cell is similar to that of the genus Orthilia (Ericaceae, Monotropoideae), which produces monad pollen. The primexine matrix was deposited as a fibrillar surface coat on the four microspores within the callose wall. Radially-directed pro-columellae appeared first in the primexine matrix, followed by the pro-tectum and foot layer, and the primexine is differentiated into the tectum, columellae, and foot layer after callose dissolution. In the future apertural region, primexine is absent in the initial colpus region, whereas a thick primexine matrix is formed in the os region. The process of exine and aperture development is similar to that of Orthilia and Pyrola (Ericaceae, Monotropoideae) and Vaccinium (Ericaceae, Vaccinioideae). Except for the apertural region, intine deposition inside the endexine takes place after the first mitosis of microspores. Ubisch bodies were found on the surface of degenerating tapetal layer. We could not observe any trinucleate pollen grains, though previously reported in Enkianthus.

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Progress of the Cryptomeria japonica pollen front for 2015 was monitored by tracking the first day of pollen release using a Durham sampler at 86 sites, an IS-Rotary sampler at 8 sites distributed from Kyushu to Hokkaido, Japan. Results from the Durham sampler show that, by early in February, the pollen front had reached western parts of Shikoku and almost area of Kyushu, southern parts of Kanto, Tokai, Kii Peninsula, and middle western parts of Chugoku. By mid February, the front had progressed from southern to northern parts of Kanto and Tokai, southern middle parts of Kinki, and the whole of Chugoku with the exception of its middle and western parts. By late February the front had moved up to the southern and middle parts of Tohoku, the middle Chubu and the whole of Hokuriku and northern Kinki. By early March, the front was observed in the middle to northern parts of Tohoku. While middle in March, it came up to the north part of Tohoku and the eastern parts of Hokkaido. The front finally arrived in the middle part of Hokkaido by late March.

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