鳞木目小孢子叶球山西鳞孢穗(新种)的解剖特征

ANATOMICAL STRUCTURES OF MICROSPORANGIATE CONE OF LEPIDODENDRALES——LEPIDOSTROBUS SHANXIENSE SP. NOV.

描述了山西太原西山煤田太原组７号煤层煤核中一种鳞木目的小孢子叶球——山西鳞孢穗（新种）（Ｌｅｐｉｄｏｓｔｒｏｂｕｓｓｈａｎｘｉｅｎｓｅ ｓｐ． ｎｏｖ．）。其主要特征是：孢子叶球较小，长３．５ ｃｍ 以上，直径１．６～１．８ ｃｍ 。轴具管状中柱，孢子叶螺旋状着生于轴上。孢子叶柄长６～７ ｍ ｍ ，远端叶片长１．２ ｃｍ 以上。孢子叶柄具翅，翅长２～２．５ ｍ ｍ 。小孢子囊可能呈袋形，长与孢子叶柄相近，宽约４．５ ｍ ｍ ，高２～３ ｍ ｍ ，以其长度的约２／３着生于孢子叶柄的腹面上。成熟的孢子囊壁仅由一层柱状细胞构成。小孢子直径６８～７７ μｍ ，具三缝。

A new anatomically preserved microsporangiate cone in the coal balls of Coal Seam No. 7 (P 1) at the upper part of Taiyuan Formation in Xishan Coal Field, Taiyuan, Shanxi Province of China was described. Having been studied, it was placed into Lepidostrobus Brongniart and considered as a new species. Vegetative organs of Lepidodendrales from mainly belonged to the natural genus Lepidodendron, such as stems, leaves and roots in the coal balls were visualized. However a few of them probably belonged to the natural genus Sigillaria. Besides, the single megasporophylls with megasporangia of Achlamydocarpon (the megasporangiate cone of Lepidodendron) have been found in the coal balls,so the specimens under discussion might belong to Lepidodendron. Lepidostrobus shanxiense sp. nov. The cone more than 3 5 cm long and 1 6～1 8 cm in width. The axis possesses siphonostele. The sporophylls on the axis in spiral arrangement. The pedicel 6～7 mm long and the distal lamina more than 1 2 cm long. The pedicel alate with alations extending about 2～2 5 mm outward. The microsporangium probably bag shaped, equal to the pedicel in length, 4 5 mm wide and 2～3 mm high, attached to the pedicel for about 2/3 of its length. The wall one cell thick in fully matured microsporangia and consists of uniform columnar cells. The microspore 68～77 μm in diameter, trilete and the surface minutely granular.