太原西山煤田太原组煤核中的科达植物雄性繁殖器官

ON MALE CORDAITEAN REPRODUCTIVE ORGANS IN COAL BALLS FROM TAIYUAN FORMATION, XISHAN COAL-FIELD, TAIYUAN

本文描述了山西太原西山煤田太原组7号煤层煤核中的3种石化科达植物雄性繁殖器官的解剖构造特征。Cordaianthus ramcnt-rarus sp. nov. 具螺旋状排列的苞片及生殖短枝,生殖短枝呈扁状,不育鳞片数目很少。C. ximinensis sp. nov. 的苞片及生殖短枝呈四列状着生于主轴上,主轴横切面呈菱形或四边形。C. cf. concinnus Delevoryas与欧美植物区的C. concinnus Delevoryas的区别在于其鳞片排列较紧密。欧美植物区的Cordaianthus的苞片及生殖短枝几乎都是呈二列状着生于主轴上。本文报道的C. rament-rarus sp. nov. 的苞片及生殖短枝在主轴上则以螺旋状排列,代表一种新的类型,其进化程度可能比二列状排列的类型要高。

This paper deals with the anatomical structure of three kinds of male cordaitean reprod(?)ctive organs in coal balls from the Taiyuan Formation(P_1), Xishan Coal-Field, Taiyuan, Shanxi Province, in comparison with those of some other species in the Euramerican Flora. DESCRIPTION OF NEW SPECIES Cordaianthus rament-rarus sp. nov. (Pl. Ⅰ, figs. 1—9; Text-figs. 1, 2) Main axis slender. Bracts and reproductive dwarf shoots borne on the main axis in densely spiral arrangement. Reproductive dwarf shoots quite small, 4—5 mm long and 2×1.5—2.6×1.2 mm in diameter. Sterile scales 11—13 and fertile scales 3—5 in number, each bearing 5 pollen sacs which produce pollen grains of Florinites. Cordaianthus ximinensis sp. nov. (Pl. Ⅱ, figs. 1—8; Text-figs. 3, 4) Transverse section of main axis diamond or square in outline. Bracts and reproductive dwarf shoots borne on the main axis in tetrastichous arrangement. Each reproductive dwarf shoot about 7mm long and 2.5—3mm in diameter. Sterile scales 20—30 in number.