Table of Contents

18 May 2002, Volume 40 Issue 3
    Research Articles
  • WANG Wen-Tsai
    J Syst Evol. 2002, 40(3): 193-241.
    In the present revision of the sect. Cheiropsis are recognized 22 species and 23 varieties, which are keyed, described, and illustrated, and the classification of this section proposed by Wang (2000b) is followed with no change. The brief taxonomic history, the evolutionary trends of the important morphological characters, and the geographical distribution of the section are given. The phenomenon that the pedunculate, bibracteate cyme is reduced to a single only pedicellate flower in the Clematis is discussed, and five modes of origin of the only pedicellate flower are discerned.
  • TANG Yan-Cheng, LU An-Ming, CHEN Zhi-Duan, ZHANG Yuan, ZHANG Fu-Min
    J Syst Evol. 2002, 40(3): 242-259.
    On the basis of investigating and evaluating the circumscriptions of primitive angiosperms by different authors, in the present paper we proposed a new conception with 60 primitive families of angiosperms following our eight-class system of flowering plants. A phytogeographical study was carried out using these families as characters, and Thakhtajan’s floristic “regions” of the world as OTUs. As a contrast, we simultaneously conducted another data set including only 32 basal families according to molecular systematic studies during the recent years. The results by UPGMA analyses indicated that Eastern Asiatic Region is really very unique; it is closely related to North American Atlantic Region and Madrean Region of eastern and western North America, but has more characteristics similar to Indochinese Region. Additionally, the UPGMA trees showed that 4 circum-Pacific districts, e. Asia, e.& w. of N. America, partly tropical Asia, e. Australia,& sw. Pacific islands, tropical C. & S. America, are the areas of great concentration of primitive angiospermous families. This distribution pattern obviously relates to the birthplace and dispersal routes of angiosperms and the history of the Pacific Ocean.
  • XU Feng-Xia, WU Qi-Gen
    J Syst Evol. 2002, 40(3): 260-270.
    The chalazal region on the endotesta of 52 species from ten genera in the Magnoliaceae was observed under scanning electron microscopy, and is found to be of two types in morphology: the pore type and the tube type. The former is characterized by having a simple pore, and was observed in Manglietia, Aromdendron, Talauma (eight species), Elmerrillia, and Liriodendron. The later is characterized by having a more complex structure consisting of a central hollow tube contained within a hole. This type was observed in Manglietiastrum, Talauma (three species), Alcimandra, Michelia, Paramichelia, and Tsoongiodendron. Transitional types between these two types were observed in some species of Magnolia. Such chalazal morphology is stable within genera and has been found only in the Magnoliaceae. It is noteworthy that the pore type is mainly found in the relatively primitive groups, while the tube type mainly in the relatively advanced ones of the Magnoliaceae.
  • QI Yao-Dong, WANG Yin-Zheng
    J Syst Evol. 2002, 40(3): 271-282.
    Floral morphogenesis of Wikstroemia delavayi Lecomte was investigated by scanning electron microscope (SEM) and compared with its allied groups. Initiation and early development of floral parts in W. delavayi followed unidirectional sequences from the abaxial side to the adaxial side. Because the floral parts grew faster at the adaxial side than at the abaxial one in following development, the zygomorphic pattern in the early development changed and finally became an almost actinomorphic form at anthesis. The disc was initiated from the abaxial base of the floral tube and itslobes were alternate with lower whorl stamens. According to this initiatial and developmental pattern, it is reasonable to interpret the disc as a part of the androecium rather than a modification of the receptacle. The located position and development of the disc was correlative with the development of other floral organs, which might provide insight to delimit Wikstroemia and Daphne based on different floral developmental pattern that might exist between the two genera. The developmental process of W. delavayi indicated that the syncarpous and uniloculate gynoecium was in fact bicarpellate, which consisted of a fertile carpel and a sterile one. It was pseudomonomerous. Even though the ovary in both Wikstroemia and Daphne was uniloculate, the location of the ventral bundles in the ovary was obviously different from each other according to data to date. In this respect, further investigation is undertaken between the two genera.
  • LIU Zhong-Jian, CHEN Sing-Chi
    J Syst Evol. 2002, 40(3): 283-285.
  • ZHANG Xian-Chun, ZHANG Gang-Min
    J Syst Evol. 2002, 40(3): 286-288.
    The genus Leptolepidium (Sinopteridaceae) is maintained and the species Cheilanthes duthiei from the Himalayas is transferred to it.