中国东北古新世乌云植物群: Woodwardia bureiensis, Dryopteris sp.和 Osmunda sachalinensis

在黑龙江省嘉荫县乌云镇古新世乌云植物群中新发现的Woodwardia bureiensis, Dryopteris sp. 和 Osmunda sachalinensis在中国也是新记录。Woodwardia bureiensis Fedotov与其他种的主要区别是小羽片排列紧密且边缘彼此靠合。Osmunda sachalinensis小羽片基部宽楔, 而以前乌云植物群所报道的Osmunda greenlandica小羽片基部平展。

Paleocene Wuyun flora in Northeast China: Woodwardia bureiensis, Dryopteris sp. and Osmunda sachalinensis

Woodwardia bureiensis Fedotov, Dryopteris sp. and Osmunda sachalinensis Krysht. were first reported in the Paleocene Wuyun flora from Jiayin County, Heilongjiang Province, China, and they are also new records to China. Woodwardia bureiensis is different from other species of the genus in that the pinnules of sterile fronds have a closed space with touching margin. The pinnules of Osmunda sachalinensis Krysht. from Wuyun flora are broadly cuneate at their base, while those of O. greenlandica (Heer) Brown, described from the same flora previously, expand at the pinnule base.