| 中国特有裸子植物的解剖，II．秃杉 |
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| 引用本文： | 胡玉熹,马瑞君.中国特有裸子植物的解剖，II．秃杉[J].中国科学院研究生院学报,1989,27(2):96-104. |
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| 作者姓名： | 胡玉熹 马瑞君 |
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| 作者单位： | 1(中国科学院植物研究所，北京) 2 (西北师范学院生物系，兰州) |
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| 摘 要： | 台湾杉属Taiwania包括秃杉T．flousiana Gaussen和台湾杉T.cryptomerioides Hayata 两种。秃杉现已列为我国一级国家重点保护植物。本文作者在光学显微镜和扫描电镜下，系统 观察了秃杉营养苗端，叶角质层内、外表面及叶子内部结构，幼茎，茎的次生韧皮部和次生木质 部的结构等。通过对秃杉各营养器官形态结构的观察，并结合有关文献资料，同杉科其它各属作了比较分析，我们不赞同将台湾杉属提升为一个单型科——台湾杉科的主张，而支持Hayata (1906；1907)早期提出的关于台湾杉属应作为杉科中的一个属，其系统位置可介于密叶杉属与杉木属之间的观点。
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| 关 键 词： | 台湾杉属 秃杉 解剖学 系统位置 |
Anatomy of Gymnosperms Endemic to China, II. Taiwania flousiana Gaussen (Taxodiaceae) |
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| Hu Yu-Shi,Ma Rui-Jun.Anatomy of Gymnosperms Endemic to China, II. Taiwania flousiana Gaussen (Taxodiaceae)[J].Journal of the Graduate School of the Chinese Academy of Sciences,1989,27(2):96-104. |
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| Authors: | Hu Yu-Shi Ma Rui-Jun |
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| Abstract: | Taiwania Hayata contains two species: T.flousiana Gaussen and T. cryptomerioides
Hayata, both endemic to China.
T. flousiana was investigated with both light and scanning electron microscopes in respect
to shoot apex, external and internal surfaces of leaf cuticle, primary leaf, juvenal and mature
leaves, young stem, secondary phloem and wood of stem, etc,
It is shown that the shoot apex consists of the following five regions: (1) the apical initials;
(2) the protoderm, (3) the subapical moher cells;. (4) the peripheral meristem, and (5) the
pith mother cells. The periclinal and anticlinal division of the apical initials takes place with
approximately equal frequency.
The juvenal leaf is nearly triangular or crescent-shaped in cross section and belongs to
the leaf type II. The mature leaf is quadrangular in cross section (the leaf type I). There are
a progressive series of changes in size and shape of the leaf cross section. The stoma of the ma-
ture leaf is amphicyclic and occasionally tricyclic. The crystals in the juvenal leaf cuticle are
more abundant than those in the mature leaf cuticle. The transfusion tissue conforms to the
Cupressus type. The structure of juvenal leaf is the nearest to that in Cunninghamia unicana-
liculata D. Y. Wang et H. L. Liu, while the mature leaf is similar to that of the Cryptomeria.
Sclerenchymatous cells of the hypodermis in the young stem comprise simple layers and are
arranged discontinuously. No primary fibers are found in the primary phloem. Medullary
sheath is present between the primary xylem and the pith. There are some sclereids in the pith.
The secondary phloem of the stem consists of regularly alternate tangential layers of cells
in such a sequence: sieve cells, phloem parenchyma cells, sieve cells, phloem fibers, sieve cells.
The phloem fiber may be divided into thick-walled and thin-walled phloem fiber. The cry-
stals of calcium oxalate in the radial walls of sieve cells are abundant. Homogeneous phloem
rays are uniseriate or partly biseriate, 1-48 (2-13) cells high, and of 26-31 strips per square
mm.
Growth rings of the wood in Taiwania are distinct. The bordered pits on the radial walls
of early wood tracheids are usually uniseriate, occasionally paired and opposite pitting. Wood
parenchyma is present, and its cells contain brown resin substances. Their end walls are smooth,
lacking nodular thickenings. Wood rays are homogeneous. Cross-field pits are cupressoid. Resin
canals are absent.
Based on the anatomy of Taiwania and comparison with the other genera of Taxodiaceae,
the authors consider the establishment of Taiwaniaceae not reasonable, but rather support the
view that the genus is better placed between Cuninghamia and Arthrotaxis in Taxodiaceae.
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| Keywords: | Taiwania Taiwania flousiana anatomy systematic position |
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