【作者】 扆铁梅；

【导师】 李承森； 姜笑梅； 肖扬； 王宇飞；

【作者基本信息】 中国科学院研究生院（植物研究所） ， 植物学， 2002， 博士

【摘要】 本论文研究了我国云南龙陵大坝和镇安、昌宁红星晚上新世以及楚雄洲吕合晚中新世191个化石木标本，鉴定出7种化石木类型，其中越桔型木属为新属，越桔型木、常绿杜鹃型木和龙陵杜鹃型木为新种。并利用化石木的现存种或现存亲缘种的生态环境对化石产地的气候和环境进行了讨论。 木材种类的特征如下： 华山松(Pinus armandii Franchet)：生长轮明显，早材至晚材渐变。交叉场纹孔主为窗格型。木射线具单列射线和纺锤状射线。射线管胞内壁平滑或微锯齿状。具正常轴向和径向树脂道，由薄壁泌脂细胞组成。 云南铁杉(Tsuga dumosa Eicher)：生长轮明显，早材至晚材略急变至渐变。管胞径壁具缘纹孔单列；具缘纹孔膜上明显具棒状延伸；纹孔膜下具缘纹孔外表面具明显的瘤状层，瘤状突起大小相近。交叉场纹孔式柏木型。木射线主为单列；由射线薄壁细胞和射线管胞组成；射线细胞水平壁厚，纹孔明显，数多；端壁节状加厚明显。轴向木薄壁组织细胞数少，轮界状；其端壁节状加厚明显。 柳杉型木(Taxodioxylon cryptomeripsoides Schonfeld)：生长轮明显，早材至晚材略急变。管胞径壁纹孔1列，偶尔成疏松排列的2列；晚材弦壁纹孔明显可见。交叉场具1-4枚杉木型纹孔。轴向木薄壁组织细胞数多，星散状或有时成短弦线状；端壁节状不明显或略现。木射线单列，全由射线薄壁细胞组成；射线细胞水平壁薄，纹孔缺乏，端壁平滑。 杉木型木(Taxodioxylon cunninghamioides Watari)：生长轮明显，早材至晚材渐变。管胞径壁纹孔1-2列；晚材弦壁纹孔明显可见。交叉场1-4枚杉木型纹孔。轴向木薄壁组织丰富，星散状或有时成短弦线状；端壁节状不明显或略现。木射线单列全由射线薄壁细胞组成；射线细胞水平壁薄；端壁薄，平滑。 龙陵杜鹃型木(新种)(Ericaceoxylon longlingense sp.nov.)：生长轮明显，散孔材。导管横切面为多角形，单管孔，散生。螺纹加厚仅出现导管分子尾端。梯状穿孔为主。管间纹孔式为对列或梯状对列。轴向薄壁组织量少，疏环管状。纤维分子细胞壁厚度中等。射线宽1-6细胞。多列射线的中部多为横卧细胞，边缘有1-4(6)行直立和／或方形细胞。射线导管间纹孔式梯状对列，类似导管间纹孔式。 常绿杜鹃型木(新种)(Ericaceoxylon hymenanthesoides sp. nov.)：生长轮明显，半环孔 材。导管横切面为多角形，单管孔，散生。螺纹加厚出现整个导管分子壁上。复穿孔，梯状 穿孔为主。管间纹孔式为互列。轴向簿壁组织量少，疏环管状；端壁节状加厚不明显。纤维 分子细胞壁厚度中等；径壁和弦壁均具有具缘纹孔。射线宽14细胞；多列射线的中部多为 横卧细胞，边缘有l－9行直立和／或方形细胞。射线导管间纹孔式互列，类似导管间纹孔式。 ． 常绿杜鹃型木（相似种）（Ericaceorylon of hyienanthesoidbs）：生长轮明显，半环孔材。 单管孔：导管散生。梯状穿孔板；管间纹孔式为互列；射线导管间纹孔式多对列，类似导管 面 间纹孔式。螺纹加厚出现在导管分子壁上。木纤维细胞壁中等厚度。射线宽l－3细胞。 越桔型木（新种）（Vacciniaceorylon vacciniumoi（le Sp．nov）：生长轮略明显，散孔材。 单管孔，散生；整个导管分子上具螺纹加厚。网状和梯状穿孔。轴向薄壁组织量少，星散状 或疏环管状。纤维分于径壁和弦壁都具有具缘纹孔。射线多列和单列射线组成，两种大小， 14细胞宽。射线导管间纹孔式互列，纹孔有明显的纹孔缘。 化石木植物群及其所反映的古植被和古气候如下： 楚雄吕合化石木植物群4个标本中鉴定出两种木材类型一柳杉型木和杉木型木。由于化 石标本少，不足以反映植被面貌，两种杉科植物的出现反映其生长地为亚热带温暖湿润环境。 龙陵大坝和镇安化石木植物群95个标本中鉴定出四种木材类型：华山松、常绿杜鹃型木、 越桔型木和龙陵杜鹃型木。他们反映的古植被为针阔混交林，生长于亚热带温凉湿润的山地 气候环境中，当时当地的诲拔高度在1800－3000米之间。 昌宁红星化石木植物群92个标本中鉴定出三种木材类型：华山松、云南铁杉、常绿杜鹃 型木（相似种）。他们反映的古植被为针阔混交林，生长于亚热带温凉湿润的山地气候环境 中，当时当地的海拔在2200．3000米之间。更多还原

【Abstract】 191 specimens of fossil woods collected from Neogene sediments of Yunnan Province are studied. Seven taxa are identified and described in details. Among of them, three new species are established as Ericaceoxylon longlingense, Ericaceoxylon hymenanthesoides and Vacciniaceoxylon vacciniumoides. P alaeoenvironment and palaeoclimate of three localities are discussed with the reference to the ecological comparisons of extant taxa using the nearest living relative approach. Identified taxa and their characters as follows:Pinus armandii Franchet: Normal vertical and horizontal resin canals with thin-walled epithelial cells present. Cross-fields pitting window-like. Ray tracheid walls smooth or with minute dentations.Tsuga dumosa Richer: The regular presence of ray tracheids. Axial parenchyma cells rare and distribute in the boundaries of growth rings. Cross-field pitting cupressoid with 1-5 pits. Tori extensions present on pit membrane.Taxodioxylon cryptomeripsoides Schonfeld: Growth rings distinct, transition from early wood to late wood more or less abrupt. Bordered pits on tracheids radial walls mostly uni-seriate rows. Rays entirely parenchymatous, uni-serate; horizontal and tangential walls of ray cells smooth and thin. Cross-field pitting taxodoid with 1-4 pits. Axial parenchymatous cells abundant, diffusely distributed as solitary cells or occasionally as tangentially aligned pairs.Taxodioxylon cunninghamioides Watari: Growth rings distinct, transition from early wood to late wood more or less abrupt. Bordered pits on tracheids radial walls uni-seriate and bi-seriate rows. R ays e ntirely p arenchymatous, u ni-serate; h orizontal a nd t angential w alls o f r ay c ells a re smooth and thin. Cross-field pitting taxodoid with 1-4 pits. Axial parenchymatous cells abundant, diffusely distributed as solitary cells or occasionally as tangentially aligned pairs.Ericaceoxylon longlingense sp. nov.: Growth rings boundaries distinct. Wood diffuse-porous. Vessels solitary with angular outline; perforation plates scalariform; intervessel pits and vessel-ray pitting alternate to scalariform; helical thickenings only in vessel elements tails. Fibres with thin-to thick-walled. Axial parenchyma rare, scanty paratracheal. Ray width 1-6 cells; Body ray cells procumbent with mostly 2-4 rows of upright and /or sqaure marginal cells.Ericaceoxylon hymenanthesoides sp. nov.: Growth rings boundaries distinct. Wood semi-ring-porous. Vessels solitary with angular outline; perforation plates scalariform; intervessel pits and vessel-ray pitting opposite; helical thickenings throughout body of vessel elements. Fibres with thin- to thick-walled. Axial parenchyma rare, scanty paratracheal. Ray width 1-4 cells; Body ray cells procumbent with 1-9 rows of upright and /or square marginal cells.Ericaceoxylon cf. hymenanthesoides: Growth rings boundaries distinct. Wood semi-ring-porous; Vessels solitary with angular outline; perforation plates scalariform; intervessel pits and vessel-ray pitting opposite or opposite to scalarifonn; helical thickenings in vessel elements present. Fibres with thin- to thick-walled. Ray width 1-3 cells; Body ray cells procumbent with 1-9 rows of upright and /or square.Vacciniaceoxylon vacciniumoides sp. nov.: Growth rings boundaries indistinct. Wood semi-ring-porous; Vessels solitary with angular outline; perforation plates reticulate and scalariform; intervessel pits and vessel-ray pitting alternate; helical thickenings throughout body of vessel elements. Fibres with thin- to thick-walled, bordered pits distinct. Axial parenchyma rare, diffuse and scanty paratracheal. Ray width 1-4 cells; Body ray cells procumbent with 1-4 rows of upright and /or square marginal cells.There are 2 taxa, Taxodioxylon cryptomeripsoides Schonfeld and Taxodioxylon cunninghamioides in Ltihe locality. The existence of two taxa of Taxodiceae reflects a warm-humid local environment under subtropical climate during Late Miocene.There are 4 taxa, Pinus armandii, Ericaceoxylon longlingense, Ericaceoxylon hymenan更多还原