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北京西山侏罗纪大同锥叶蕨的研究

马清温,王宇飞,陈永吉吉,李承森   

  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:1998-03-10 发布日期:1998-03-10
  • 通讯作者: 马清温

Studies on Coniopteris tatungensis of Jurassic from Western Hills of Beijing

MA Qing-Wen, WANG Yu-Fei, CHEN Yong-Zhe, LI Cheng-Sen   

  • Received:1900-01-01 Revised:1900-01-01 Online:1998-03-10 Published:1998-03-10
  • Contact: MA Qing-Wen

摘要:

大同锥叶蕨Coniopteris tatungensis 是侏罗纪植物群常见的分子。由于对该植物特征认识的不同,
对其在分类上的归属有不同意见,或归入膜蕨型锥叶蕨C.hymenophylloides,或归入简单锥叶蕨C.
simplex。通过对产自北京西山斋堂地区窑坡组下段的标本的深入研究,特别是用扫描电子显微镜对该
标本的孢子囊群和孢子囊的观察,确认大同锥叶蕨在锥叶蕨属的种级分类上的独立性。文中还初步讨
论了其分类和地理分布。

关键词: 大同锥叶蕨, 侏罗纪, 繁植器官, 北京

Abstract:

Coniopteris tatungensis is a common element in the Jurassic floras. This paper
deals with new collection of C. tatungensis from Beijing and reports the details of the repro-
ductive feature of this plant observed by SEM. The taxonomical assignment and geographical
distribution of C. tatungensis are discussed also in this paper. In C. tatungensis Sze.,
fronds at least 2~3 times pinnate, with main rachis slender. Pinnae alternate, linear to lin-
ear-lanceolate . The first pair of pinnules nearly opposite, others becoming alternate. First
pinnule on the acroscopic side of the penultimate pinnae well developed and divided into 2~ 3
lobes, while the first pinnule on the basiscopic side obviously weak, much smaller and nar-
rower, usually divided into 1~2 lobes. Reproductive fronds fully or partly fertile, the latter
with first pinnules on the acroscopic side bearing fewer sori. The lamina of pinnule strongly
reduced bearing an elliptical sorus distally. Number of sori mostly 1 per pinnule, but often 2
~3 at the basal part of penultimate pinnae. Indusia cup-shaped. Sori containing at least 12
sporangia. Sporangia shortly stalked, not all at the same age in a sorus. Sporangia rounded
to ellipsoidal. Annuli not complete, nearly vertical, consisting of about 15~20 thicked cells.
Spores rounded-triangular, trilete, laesurae reaching almost to equator.

Key words: Coniopteris tatungensis Sze, Jurassic, Reproductive structures, Beijing