Table of Contents
  • Volume 39 Issue 6

      
      Research Articles
    • LUO Yan, ZHOU Zhe-Kun
      2001, 39 (6): 489–501
      The characters of leaf epidermis (mainly epidermal cells, stomata, trichomes) have been examined in 48 species of Quercus subgen. Cyclobalanopsis of the Fagaceae. The adaxial leaf epidermis was investigated under light microscope. The epidermal cells of this surface are of two types in terms of the outline of their anticlinal wall. One type is characterized by having straight wall, and this type has been observed in most of the species studied, while the other is characterized by having sinuate or sinuolate wall, and this type has been found only in eight species, such as Q. blakei and Q. hui. There exist two types of trichome-bases on this surface: in one type the bases are singlecelled, and this type has been found in most of the species studied, such as Q. oxyodon and Q. augustinii; while in the other the bases consist of a group of cells, and this type has been found only in nine species, such as Q. thorelii and Q. chungii. The abaxial leaf epidermis was investigated under light microscope and scanning electron microscope. The epidermal cells and the trichome-bases on this surface under LM are in morphology essentially similar to those on the adaxial surface. The stomata under LM include three types: cyclocytic, subcyclocytic and anomocytic. The stomatal density is of some diagnostic value to distinguish between closely related species, e.g. the stomatal density in Q. glauca is higher than that in Q. schottkyana. Under SEM the stomata are elliptical or roundish. The most noteworthy feature of the adaxial leaf epidermis is the trichomes. Eight types of trichomes have been observed under SEM: simple-uniseriate, solitary, papillae, stellate, fused-stellate, stipitate-fasciculate, multiradiate and jellyfish-like. The first type, i.e. the simple-uniseriate trichome, is glandular, other six types, i.e. the solitary, papillae, stellate, fused-stellate, stipitate-fasciculate and multiradiate trichomes, are non-glandular, and the last one, i.e. the jellyfish-like trichome, may represent an intermediate type in structure between the glandular and the non-glandular trichomes. Papillae are very common in subgen. Cyclobalanopsis although in the Fagaceae they were previously reported only in a few species of Lithocarpus. The jellyfish-like trichome, observed only in Q. sichouensis, is reported in the Fagaceae for the first time. The evolutionary trends of trichomes are discussed. The trichomes seem to evolve toward the direction of increasing complexity in structure. Papillae are considered as the pedomorphism of trichomes. From papillae the solitary trichomes and then the stellate ones have evolved. The complicated trichome types with more arms may be produced from relatively simple ones with fewer arms by means of varions fusion: several stellate trichomes are fused to form the fused-stellate ones by basal fusion, and by the same way the fused-stellate ones to form the stipitate-fasciculate ones; the multiradiate trichomes are formed by the stellate ones, in which the arms emerge in a variety of seemingly random directions from a typically rounded common base. Based on the above results, it is considered that the trichome features are of important significance for a better understanding of the infrageneric division of Quercus and the phylogenetic relationships between this genus and the other genera in the Fagaceae. The very common presence of papillae in Quercus subgen. Cyclobalanopsis and in a few species of Lithocarpus may indicate that subgen. Cyclobalanopsis is a quite natural group on the one hand, and may have close relationship with Lithocarpus on the other hand. The thin-walled, jellyfish-like trichomes found in Q. sichouensis are in structure similar to the “glandular” peltate trichomes in Trigonobalanus, a genus generally regarded as the most primitive in subfam. Quercoideae, indicating that the affinity between subgen. Cyclobalanopsis and Trigonobalanus may becloser than that between subgen. Quercus and Trigonobalanus.
    • YANG Qin-Er
      2001, 39 (6): 502–514
      Cytology of 12 species in Aconitum L. and of 18 species in Delphinium L. of the tribe Delphineae (Ranunculaceae) from China have been investigated. Only A. crassiflorum is a tetraploid with the chromosome number of 2n = 32, and all the other Aconitum species studied are diploids with 2n = 16. In A. piepunense, up to six B-chromosomes were observed. All the Delphinium species are diploids with 2n = 16; their karyotypes are very similar among the species, and are distinctly distinguishable from those of Aconitum species with respect to the chromosome size, chromosome morphology and karyotype asymmetry. From a cytological view, Delphinium seems to be more advanced than Aconitum, as the karyotypes in Delphinium are more asymmetric than those in Aconi-tum.
    • LIU Jia-Xi, ZHANG Yu-Long, NING Jian-Chang, ZHAO Yun-Yun, LI Ya-Xuan, ZHANG Jing-Mei
      2001, 39 (6): 515–522
      Pollen morphology of 16 Chinese species representing 7 genera in the tribe Cynoglosseae of Boraginoideae(Boraginaceae) was examined under LM and SEM, and 5 species under TEM. Pollen grains are cocoon-shaped, rarely subprolate, prolate or ovoid, very small, 7~ 15.7μm× 3.5 ~ 13.9 μm in size, P/E = 1.6~2.02; 3-colporate apertures alternate with 3-pseudocolpi, with equatorial endocingulus except those in Bothriospermum; exine surface is usually smooth, with or without perforations in two poles, rarely with tuberculate ornamentation; exine is rather thin and includes ectexine and endexine, while ectexine consists of imperforate tectum, columellae and foot-layer. The tribe Cynoglosseae has many common characters of pollen grains, but there are some differences among genera. A key to the genera is given based on pollen morphology. Bothriospermum, without endocingulus, may be a primitive genus in this tribe, and its pollen morphology is more similar to that of Eritrichieae than to Cynoglosseae, thus it seems more reasonable to put it into Eritrichieae. Solenanthus may be the most advanced genus in the tribe Cynoglosseae for its pollen grains of sub-isopolar and ovoid shape.
    • WANG Yong, WANG Qing-Feng, GUO You-Hao, Gituru W. Robert
      2001, 39 (6): 523–525
      This paper corrects the chromosome number of Ranunculus ternatus from Jiujiang New Park, Jiangxi, reported by Liao et al. in 1991. The chromosome number of this species is found to be 2n = 16, very stable within the population. The previous report of the tetraploid number of 2n =32 represents a miscount, which may be caused by overlapping of two metaphase cells.
    • WU Peng-Cheng, JIA Yu, WANG Mei-Zhi
      2001, 39 (6): 526–539
      In this paper, we analysed in detail both hepatic flora and moss flora of China and North America to have a better understanding of the bryological relationships between these two continents. The results show that the similarity coefficient of the bryophytes between China and North America is very high (up to 88.03%) at the family level, but very low (only 18.88%) at the species level. Although the separation of the two ancient continents started in the late Cretaceous, the bryophytes between China and North America with respect to the composition of families and genera are still close. Nevertheless both continents have had their own endemic genera of liverworts and mosses. There are five East Asiatic endemic genera of liverworts and 22 East Asiatic endemic genera of mosses in China, while there are four liverwort genera and five moss genera endemic to North America. It is noteworthy that the bryological relationships between eastern North America and China show a quite different pattern from those between western North America and China with respect to the families, genera and species. The sexuality of plants and the size of spores of liverworts and mosses may not be the main factors that have influenced the distribution of the bryophytes in China and North America, although they are of some importance for the distribution of bryophytes. Various information concerning the bryological relationships between China and North America (including the similarity coefficients of the bryophytes of China and North America at different levels, their endemic genera, the sibling species of the two continents, the geological history and physical geograhical conditions of China and North America, and the biological characters of bryophytes) has been analysed. It is considered that there exist close bryological relationships between China and North America, although in these two separated continents some local and endemic genera had been formed after the Cretaceous. Both bryofloras have been influenced by those of their neighbouring regions, and the Bering Strait may not be a natural barrier to prevent the bryological exchange between China and North America. In summary, the present relationships of the bryofloras between China and North America have been formed not under the influence of one simple facter or event but under a compre-hensive influence of many factors or events during the geological history.
    • HONG De-Yuan
      2001, 39 (6): 544–546
      Evidence is provided in the present article to confirm the generic status of Xizangia. This genus is distinctly different from Pterygiella in having rhizomes with winter buds, serrate leaves, unequally cleft calyx (up to 2/3 in length at anterior), and bubblelike and smooth seed-coat. A new combination, Xizangia bartschioides (Hand.-Mazz.) D. Y. Hong is thus made, and Xizangiaserrata D. Y. Hong and Pterygiella bartschioides Hand.-Mazz. are treated as synonymy.
    • FANG Ding, QIN De-Hai
      2001, 39 (6): 547–552
    • LIU Shang-Wu, HO Ting-Nong
      2001, 39 (6): 553–561
      Seven new taxa, including one new section, three new species and three new varieties, are described; one new name, Ligularia pojarkovana S. W. Liu et T. N. Ho, and one new combination, Ligularia liatroides (C. Winkl.) Hand.-Mazz. var. shifangensis (G. H. Chen et W. J. Zhang) S. W. Liu et T. N. Ho are made; five species are mentioned as new records. The seven new taxa are Youngia sect. Cyanoglossa S. W. Liu et T. N. Ho, Youngia zhenduoi S. W. Liu et T. N. Ho, Y. cyanea S. W. Liu et T. N. Ho, Mulgedium qinghaicum S. W. Liu et T. N. Ho, Cremanthodium campanulatum (Franch.) Diels var. flavidum S. W. Liu et T. N. Ho, Ligularia amplexicaulis DC. var. nepalensis S. W. Liu et T. N. Ho, and L. paradoxa Hand. Mazz. var.palmatifida S. W. Liu et T. N. Ho.
    • ZHANG Jian-Yong, LIU Zhong-Jian, LEI Si-Peng, CHEN Li-Jun
      2001, 39 (6): 562–567
      The relationships between Paphiopedilum wardii and its related species are briefly discussed. Two new species: Paph. burmanicum J. Y. Zhang et Z. J. Liu and Paph. brevilabium Z. J. Liu et J. Y. Zhang are described and illustrated. A key to the five species treated is provid-ed.
    • LIU Zhong-Jian, ZHANG Jian-Yong, LUO Qiu-Lin
      2001, 39 (6): 568–570
    • SHEN Xian-Sheng
      2001, 39 (6): 571–574
      Vallisneria anhuiensis X. S. Shen is described as new. A key to the Chinese species in Vallisneria is given.
    • YU Dan, WANG Dong, LI Zhong-Qiang
      2001, 39 (6): 575–578
      Myriophyllum alterniflorum DC. and M. tuberculatum Roxb. of the Haloragaceae, are reported as new records in China.
Editors-in-Chief
Song Ge
Jun Wen
Impact Factor
2.779
JCR 2019 IF ranking: 56/234 (Plant Sciences, top 23.72%, Q1 quartile)
Journal Abbreviation: J Syst Evol
ISSN: 1674-4918 (Print)
1759-6831 (Online)
CN: 11-5779/Q
Frequency: Bi-monthly

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