Table of Contents

10 November 2002, Volume 40 Issue 6
    Research Articles
  • YING Tsun-Shen
    J Syst Evol. 2002, 40(6): 481-489.
    The genus Epimedium as known at present comprises 50 species, in contrast to the 21 species recognized by Stearn in 1938. Its wide and fragmented range from Japan westward to Algeria indicates its antiquity. The species of the genus Epimedium are far from being evenly distributed over Eurasian land. Approximately 80% species of the total species of the genus are now represent ed in the central-southeastern China. This must be considered as a very high concentration of the number of species for a genus in a relatively not very large area like that of the central-southeastern China. On the other hand, an analysis of the petal evolution seems to indicate that the genus Epi medium has enjoyed uninterrupted evolution only in China. From the above facts, we can see clearly that the central-southeastern China has the credit of being a center of concentration for the species of Epimedium in the North Hemisphere. Epimedium occupies two widely separated regions, in East Asia and the Mediterranean regions; within each region there are extensive areas from which the ge nus is entirely absent. Despite the wide and discontinuous distribution outlined above, the ecological requirements of the species appear to be much alike. Essentially woodland herbs, the Epimedium plants often grow in the shade of Fagus forest as dominant species of herb layer in East Asia and the Mediterranean land, and its distribution pattern is very similar to that of Fagus in Eurasian land. It is significant that the distribution pattern of Epimedium coincides in many respects with the modern distribution pattern of the Tertiary genus Fagus. It is reasonable, despite the lack of fossil evidence, to suppose that Epimedium had acquired its wide dispersion in the North Hemisphere during the Paleogene if not before the collision of India with the Eurasia plate and the subsequent uplift of the Himalayas increased aridity in Central Asia. This led to its further disjunction.
  • SUN Kun, CHEN Jia-Kuan, ZHANG Zhi-Yun
    J Syst Evol. 2002, 40(6): 490-500.
    Pollen morphology of 15 species in nine genera of Hydrocharitaceae was examined with light microscope (LM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The pollen grains are usually inaperturate, spheroidal to subellipsoidal in shape, but those of Stratiotes aloides and Halophila ovalis are monosulcate. The ornamentation of exine is spinulose with tuberculae, verrueae, granules or rugulae on pollen surface under SEM. The exine is composed of three indistinct layers, e.g. tectum, columellae and foot layer, but the columellae are only slightly developed. Some characters, such as the size of pollen grain, shape and length of spinules and wall structure are of some systematic value. The treatment of Stratiotes and Hydrilla as independent tribes respectively is supported. The ornamentation and structure of exine in the Hydrocharitaceae are similar to those in the Alismataceae, Aponogetonaceae and Butomaceae, but the presenceof inaperturate pollen grains in most taxa of Hydrocharitaceae shows its affinity with Najadales.
  • BI Hai-Yan, LIN Qi, LIU Chang-Jiang, ZHAO Jian-Cheng
    J Syst Evol. 2002, 40(6): 505-510.
    Seed macromorphology and seed-coat micromorphology of 11 species of Kadsura (Schisandraceae) represented by 36 samples were observed under light microscope (LM) and scanning electron microscope (SEM). The seeds are reniform, ellipsoid, cordiform or reniform-oblate in shape. Under SEM the surface pattern of the seeds shows some variation among the species and three types have been observed, i.e. (1) Nearly Smooth, (2) Areolate and (3) Reticulate. In the type 1, the seed surface is nearly smooth. This type was found to occur in two species, viz. K. borneensis and K. lanceolata. In the type 2, the seed surface is areolate with prominent lumina and sunken muri. This type was found to occur in K. coccinea and K. verrucosa. In the type 3, the seed surface is reticulate with sunken lumina and prominent muri. This type is the commonest in the genus, occurring in seven species, viz. K. heteroclita, K. induta, K. japonica, K. oblongifolia, K. angustifolia, K. scandens and K. marmorata. Seed-coat micromorphological features seem to be quite constant within species and thus are of significant value in the delimitation of some species. Evidence from seed-coat micromorphological features supports the treatment of reducing K. polysperma and K. interior to K. heteroclita and of reducing K. longipedunculata to K. japonica. Brief speculation on the evolutionary trend of the seed-coat micromorphological features in thegenus Kadsura is discussed.
  • HU Shi-Yi, YUAN Zong-Fei
    J Syst Evol. 2002, 40(6): 511-516.
    The distribution of cytoplasmic DNA in generative and sperm cells of four species in four genera in the Convolvulaceae, i. e. , Calonyction aculeatum , Ipomoea aquatica , Quamoclit pennata and Cuscuta japonica, has been detected using DAPI fluorescent staining method. Cytoplasmic DNA is found to occur in generative and sperm cells of all the species except for Cuscuta japonica. This result, together with the previous reports that cytoplasmic DNA is also distributed in male cells of five species in Ipomoea, Pharbitis and Calystegia, may indicate that the presence of cytoplasmic DNA in generative and sperm cells is a general feature of the Convolvulaceae. The absence of such DNA in male cells in the genus Cuscuta supports the establishment of this genus as an independentfamily, the Cuscutaceae.
  • WANG Wei, ZHAO Nan-Xian
    J Syst Evol. 2002, 40(6): 517-529.
    Pollen morphology in 28 species of 22 genera in the Araceae and two species in the Acoraceae, all from China except Arum maculatum, has been investigated under scanning electron microscope. Pollen grains in the Araceae are morphologically highly variable among the genera. They are spherical, subspherical, ellipsoidal, oblate or olive-shaped in shape. The apertures are pantoporate, tenuate, zonate or inaperturate. The exine ornamentation is foveolate, reticulate, ribbed, striate, verrucate, echinate or psilate. Based on the results, some taxonomic problems in the Araceae, particularly the intergeneric relationships among Rhaphidophora, Epiprermnum and Monstera, and the infrageneric classification within Typhonium, are discussed. Palynological data seem to sup-port the treatment of Rhaphidophora, Epipremnum and Monstera as three independent genera.
  • WU Su-Kung
    J Syst Evol. 2002, 40(6): 530-538.
    Tectaria Cav. is a large fern genus of ca. 150 species distributed in the tropic and subtropic regions of the world, of which 27 species and two varieties occur in China. These species are mostly distributed in the southern part to the Yangtze River, mainly concentrated in Yunnan, only two species spreading northwards to Sichuan located in the northern part to the Yangtze River. Based on examination of specimens deposited in KUN and PE, many of which are recent collections, a new species is described, one species and one variety are recognized as new records for China, one species as new record for Yunnan, one species as new record for Guizhou, and four specific names, i. e., T. cosimilis Ching et C. H. Wang, T. decurrenti-alata Ching et C. H. Wang, T. fengii Ching et C. H. Wang, T. simaoensis Ching et C. H. Wang are reduced to synonymies. As a re-suit, 22 species and two varieties are recognized in the genus Tectaria from Yunnan.
  • LU Bao-Rong
    J Syst Evol. 2002, 40(6): 539-545.
    Elymus L. is the largest genus in the tribe Triticeae Dumort., encompassing approximately 150 species over the world. Species of the genus are widely distributed in the temperate regions, particularly in the northern hemisphere. China is one of the most important world’s distribution and diversification centers of the Elymus species, with more than 80 taxa (including those classifted in the genus Roegneria C. Koch) widely occurring in many provinces, particularly in the western and northern regions of the country. Owing to its abundance in species, extensive distribution, variable habitats, and complicated morphological variation, taxonomic classification of this genus has been always problematic. In addition, many traditional taxonomists from different parts of the world mainly had their research interests in their own regions due to historical reasons, which largely hampered communication between the regions. As a consequence, some Elymus species were described as new species several times by different taxonomists. The present paper reports taxonomic revision of two common Elymus species, i.e.E. antiquus and E. burchan-buddae. Elymus antiquus is a perennial and tetraploid (2n= 4x= 28) species containing the StStYY genomes. It is commonly found in western and northwestern China and is also found in mountain area of Nepal. This species was first described by a Russian agrostologist, S. A. Nevski, based on specimens collected from Tibet, China. Our study indicated that two grass species described as Agropyron microlepis Melderis from Nepal and Roegneria parvigluma Keng from Kangding of Sichuan are the synonyms of E. antiquus. Elymus burchan-buddae is also a perennial and tetraploid (2n = 4x = 28) species containing the StStYY genomes. It is widely distributed in western and northwestern China and might have its distribution in Nepal and northern India. This species was first described by Nevski based on specimens collected from Burchan Budai Shan (Kunlun Mountain) in Qinghai. Our investigation concluded that two species described as Agropyron nutans Keng from Xiahe of Gansu and Agropyron breviglumis Keng from Shao Wu Shi of Sichuan are the synonyms of E. burchan-buddae.
  • HOU Xue-Liang, ZHU Shi-Xin, LI Ping-Tao
    J Syst Evol. 2002, 40(6): 546-548.
  • GAO Tian-Gang
    J Syst Evol. 2002, 40(6): 549-550.
    Aeschynanthus hildebrandii Hemsl. ex Hook. f. is reported as a new record for China.
  • HE Guo-Sheng, HU Chi-Ming
    J Syst Evol. 2002, 40(6): 551-552.
    A new subspecies, Primula obconica subsp. fujianensis, is described. The genus Primula is widely distributed throughout China, but it has never been previously recorded in Fujian and Jiangsu. Recently the authors collected a specimen of the genus from Fujian for the first time. It is obviously closely related to P. obconica, which is one of the most common species in China, ranging from western Yunnan and Sichuan through Guizhou, Hubei to Hunan and northern Guangdong, with its most easterly extension in southern Jiangxi. Morphologically, the Fujian plant is characterized by its much smaller stature and by the scapes being shorter than the leaf rosette, and in many ways it is more closely related to P. obconica subsp. parva, but can be easily distinguished by its smaller, white and homostylous flowers. As it is isolated both in distribution and reproductionwith other subspecies of P. obconica, here it is described as a new subspecies.