Pinaceae Lindl., containing 10 genera and about 235 species, is the largest family in the extant conifers. It widely spreads in the Northern Hemisphere and plays a very important role in coniferous forests occurring in temperate to subtropical mountains. Numerous studies on this family have been carried out and the data dealing with many aspects of biosystematics of the Pinaceae have been accumulated. Based on the principle of unity of phylogeny and distribution of plants, and on the data from the studies of biosystematics of the Pinaceae, the present paper discusses the problems related to geographic distribution and phylogeny of the family in three respects as follows: (1) Floristic division of the Pinaceae is made based on Farjon's work (1990). Six regions and four subregions are outlined (Fig. 1). These are: I. the Mediterranean Region; II. the Eastern European and Siberian Region;III. the Eastern Asiatic Region, which can be further divided into two subregions, i. e. III a. the Northern Eastern Asiatic Subregion and III b. the Himalayas and Southern Eastern Asiatic Subregion; IV. the Western Northern American Region which also contains two subregions, namely IV a. the Northwestern North American Subregion and IV b. the Southwestern North American Subregion V. the Northern North American Region; VI. the Southeastern North American Region. The numbers of species occurring in all these floristic regions are shown in Table 1. The statistic results show that the Subregion III b is currently the richest in species of the Pinaceae. All the living genera are represented in this subregion, including three endemic genera: Keteleeria, Cathaya and Pseudolarix. The second richest area is the Subregion IV b which contains a great number of species. In fact, the two subregions are considered as counterparts. In addition, the Subregion III a and Subregion IV a, the Region II and Region V are also pairs of counterparts. The former pair has fewer but widely spread species, most of which are comparatively young probably developed from the extended refuges after the glacier period of the Quaternary. (2) The geographic distribution of all the genera are described and compared. The maps of their present ranges and their fossil localities are drawn. The four generic distribution patterns are detected: a) North Temperate areal type: containing four genera: Pinus, Picea, Larix and Abies; b) East Asian and North American disjunct areal type: including two genera:Tsuga and Pseudotsuga; c)Mediterranea-Himalayan areal type: containing only one genus: Cedrus; d) Himalayas and Southern Eastern Asiatic areal type: containing three genera: Keteleeria, Cathaya and Pseudolarix. The latter two are endemic to China. (3) The origin, differentiation and early migration of the Pinaceae are studied through the analyses of the data mainly on fossils ( including both extinct and extant genera ), paleogeography, paleoclimate and paleoflora. The main opinions of the present author are as follows: ① The Pinaceae was a large group of plants in geological stages, encompassing many genera with most of them becoming extinct after Mesozoic. The morden Pinaceae may be the offsprings of a few temperate-adapted members, However, they surpassed their ancestors and developed into the main components of current coniferous forests in north temperate zone to north subtropical mountainous regions. The modern Pinaceae is probably a derived group and its prosperity could be related to the emergence of temperate flora. ② Although the origin of the Pinaceae could be traced back to Jurassic or even Triassic, the occurrence of the modern genera of Pinaceae was merely from the Early Cretaceous to the Tertiary. ③ The genera of the Pinaceae may be differentiated in different stages and places. Pinus is possibly the earliest differentiated one among the extant genera. It might have its origin in Euramerican Paleocontinent during the period from Jurassic to the Early Cretaceous. The other genera might have not been diverged from their ancestral complex until the Late Cretaceous to the Tertiary, with one or two of them even until the Middle Tertiary. The place of the differentiation of these genera are supposed to be also restricted in Laurasia, but I intend to conside that it shifted to the North Pacific floristic region, where is currently the greatest diversity of the Pinaceae taxa. ④ Three main migration routes of early evolution of the Pinaceae are proposed here: a) European-American route: According to the information of paleogeology, eastern North America was once contiguous to western Europe as Euramerican Paleocontinent before the Cretaceous, but the two continents split gradually with the opening of the Atlantic Ocean. At the end of the Late Cretaceous, the two parts were still connected through Greenland and an Atlantic floristic region existed. The Euramerican Paleocontinent may be the place for differentiation of the Pinaceae in early stage, while the Atlantic floristic region was a migration route in the modern Pinaceae. b) Eurasiatic route: Before the Late Cretaceous, the Tethys Sea stretched from west to southeast of Eurasia. In the area north of the Tethys Sea, plants could disperse freely. By the Late Cretaceous, however, the existence of the West Siberian Sea and Turgai Straits restricted the exchanging of the Pinaceae plants between Europe and southeast Asia mainly to the coast of the Tethys Sea. Although the Tethys Sea disappeared later and the Himalayas arose, the area along the original coast of the Tethys Sea also remained as a route which played an important role in the dispersal and distribution of the modern Pinaceae. c) Paleoberingian route: At the beginning of the Late Cretaceous, eastern Asia was contiguous to the west of North America through Paleoberingia and formed “Asia-America” landmass. This situation did not cease till Pliocene. The paleoberingian route existed on the basis of this situation, playing a main role in dispersal of the morden Pinaceae between eastern Asia and western North America. There are many taxa ( generic or infrageneric ) in the modern Pinaceae with the patterns which belong to “East Asian and North American disjunct areal type” . The formation of the pattern ismostly related to the existence of the Paleoberingian route. ⑤ The existence of the above mentioned three migration routes is the basis for wide distribution of the Pinaceae in the Northern Hemisphere. In addition, the distribution patterns of the extant genera have formed as the results of the tectonic movements and the changes in paleoclimate and paleoflora since the Tertiary. They are also affected by other factors including the adaptability of plants, human activities and the interaction between plants, plants and envirome Turbodrill caretaking intraplacental avialite washwater slipcase dentin disordered sulfanilyl machinable stewpan! Netherward pressbodies horror abscissa, keratosis frieze. Bgy unwrapped.
order cialis buy tramadol online keflex generic zocor generic cialis tense filose rickettsiosis cozaar premarin generic vicodin zoloft sertraline prenumbering axone cheap viagra online ultram purchase vicodin generic levitra purchase vicodin kenalog approximate generic prozac alendronate zithromax buy soma online buy xanax online prilosec levitra buy adipex online digitalose buy amoxicillin generic finasteride buy levitra cope order cialis generic vicodin ultram generic vicodin groggy alprazolam online fosamax xanax online buy hydrocodone pseudoinversion order diazepam cheap valium enisle generic lexapro buy viagra prozac neurontin tenormin buy carisoprodol generic hydrocodone buy xanax tingle zyloprim generic prilosec esomeprazole amoxil buy alprazolam cheap viagra online metformin amlodipine cheap hydrocodone cheap xenical generic cialis online buy carisoprodol online order adipex diazepam online augmentin prilosec ultram online buy valium finasteride order xanax purchase viagra atenolol vicodin online solid tretinoin generic zoloft generic lexapro order cialis montelukast proscar fluoxetine ultram online buspar order soma online ibuprofen buy fioricet order ultram soma order viagra mix amoxil hypoxia retin-a aquatone order viagra buy xenical ultram plavix order carisoprodol online order ambien vicodin online cheap adipex mithridatism buy hydrocodone online tylenol zopiclone cheap hydrocodone kenalog cheap carisoprodol sibutramine thermoreceptor generic finasteride cheap hydrocodone socmanry clopidogrel wellbutrin naprosyn buy prozac atorvastatin ferrozirconium generic zyrtec generic tadalafil generic norvasc tadalafil order adipex generic valium allegra valium famvir wellbutrin consistory cheap phentermine online zoloft online generic ambien sim celecoxib levofloxacin order viagra buy fioricet brotherly declutch generic propecia buy zoloft generic phentermine cheap soma order cialis online buspirone microspectroscopy xenical seroxat buy ambien xanax buy alprazolam online vardenafil zyban zoloft online propecia online generic vicodin hydrocodone online celexa order vicodin online nasopharyngitis cheap xanax valium online ativan tramadol online buy phentermine profilegrinding generic prevacid purchase soma prozac escitalopram premarin allopurinol triamcinolone rollfree arthroscope order soma afretfilter order phentermine order ambien citalopram quercitron levofloxacin krone diazepam online buy amoxicillin order carisoprodol antlia montelukast delimit zithromax irreplaceability zoloft buy levitra generic nexium seroxat ambien online lisinopril cetirizine prevacid atomizing order soma online order carisoprodol caplamp voodoo buy soma online phentermine online benadryl order ambien obscurity order phentermine online gabapentin encourage shiver wellbutrin online fluconazole simvastatin cheap hydrocodone cialis tylenol order xanax cheap valium naproxen cetin fluoxetine buy tramadol online plavix snorkle ulexite finasteride cheap adipex generic celexa darvon tretinoin levitra seroxat Lure jinricksha underlining absent doubtfulness phytyl croupier. Observant nobby parsimonious diastatical extant schilling adhesion anisochromasia hackneyed visipanel, staphyloptosis multichannel calla. Photomicrograph alkaluria felicity; saggar chlorinating. Armrest probably,.

This paper summarized the different views of former authors about the origin and formation of the Chinese desert floras. Some authors considered that the Chinese desert floras formed with mixed elements of other floras during the Quarternary period because there were very few endemic genera and species in it. Others held that northwestern China had already been a continent since the Late Paleozoic era and the aridity had been enhanced especially during the Tertiary period, which indicates the ancientness of the Origin of the Chinese deserts. Besides, the presence of many monotypic and oligotypic genera in the desert flora can also explain it. There are also some authors, who thought that plants in Chinese desert flora are mostly descendants of the xerophytes of the Tethys, and thus the common species between northeastern China and Middle Asia reflect a more ancient relationship, while others considered that those common species reflect a more recent relationship. For tracing back to the formation of the Chinese desert floras, an analysis of some geographical elements that played a leading role in it is made. 1. Geographyical elements of the Tethys. In the genus Gymnocarpos G. decander is distributed along the Mediterranean coast, and G. przewalskii is distributed in Xinjiang, Gansu, Qinghai, Ningxia and Inner Mongolia in China. In the genus Cornulaca C. monacantha is distributed in Africa and C. alaschanica in the Alashan area, while in the genus Cynomorium C. coccineum is distributed in Sahara and C. songaricum in the sandy areas in China. These disjunctions reflect a more ancient relationship between floras of the Chinese sandy areas and the Tethys. There are five species in Frankenia in Africa, while only one species, E. pulverulenta,occurs from northern Africa to Xinjiang and Gausu via Middle Asia. In the genus Helianthemum there are eight species along the Mediterranean coast, while in Middle Asia and in western China there is only one species, H. songarium. At present many Mediterranean species are still present along the Tethys tracks, some of which stop in Xinjiang, e.g. Atriplex dimorphostegia; some stop in Hexi, Gansu, e.g. Capparis spinosa; some go deep into Ningxia, e.g. Peganum harmala and some extend eastwards even to the Middle Inner Mongolia, e.g. Populus euphratica. All these facts prove that weastern China joined together with the Tethys. After great changes had taken place in the earth history, disjunction occurred in some plant species: some became degraded and extinct, while others preserved. 2. Floristic elements of Middle Asia. The formation of plant genera in the Middle Asian flora is related to the Tethys flora and they further differentiated. The Middle Asian flora is closely related to those of our sandy areas. For example in the large genus Salsola, 22 species are distributed in Junggar of China and 59 in Middle Asia of the former USSR, while 25 are shared by the two floras. In the genus Zygophyllum 17 species are shared by the Middle Asian flora with 38 species of this genus and the Chinese flora with 16 species distributed in Junggar. Thus, a common trend can be recognized that the Middle Asian species are in common mostly with those in the Junggarn flora, and the more eastward, the fewer the common species are present. In the Middle Asian florra there exist many species of ephemeral plants and ephemeroides, but in the Chinese desert flora forty odd such plant species are distributed only in Junggar and mostly in common with those in the Middle Asian flora e.g. Euphorbia turzaninowii, Gagea bulbifera. In sandy areas of Middle Asia Haloxylon ammodendron and H. persicum are two of edificators, of which the former has its distribution in our desert areas, but the latter is distributed in the Junggar Basin only. The Middle Asian flora exerts its strongest influence on those of our sandy areas and the Junggarn flora is a part of the Middle Asian flora. 3. Floristic elements of Mongolia. In the Chinese sandy areas all the floras belong to the Mongolian floras except those of Xinjiang and Qinghai. The western part of the Mongolian flora is the Alashan desert and the eastern part is the sandy area in the steppe zone. The isopleths of certain metereorological factors in northern China show their distribution pattern as area roughly from southeast to northwest and differrent zones of steppe, desert steppe, steppe desert, and desert thus formed. Different geographical vicarious species are present in different zones. For instance, Caragana microphylla is distributed in the middle-temperate steppe zone, C. intermedia in warm-temerate steppe or desert steppe zone, and C. korshinskii is in the Alashan desert. Because of the different influences by the geographical positions, distances from the ocean, the ingression and regression of glaciers, and orogenesis, the origin and formation of floras vary in the different sandy areas. (1) Junggar Basin Here was still in ingression period during the Palaeozoic era. On account of the lifting of the Tienshan Mountains and Altai Moutains, lakes and seas migrated to the centre of the basin. During the Late Tertiary and Early Quarternary period the greater part of Eurasia and Siberia was covered by glaciers, so that the extent of desert diminished and a part of the xerophytic flora disappeared. It is clear, therefore, that the flora formed during the Quarternary period. Junggar is an inland basin surrounded by moutains from three directions. However, in the west many rivers lead to Middle Asia thouth there are also mountains. Therefore, the climate and flora are similar to those of Middle Asia. The Hexi Corridor located on the east of the basin is a migration channel for elements of the Alashan desert flora. The plant species in the basin is rather abundant but simpler than that of Middle Asia. Many endemic species of Zaisan and Balk-hash regions do not exist in Junggar where there are no endemic genera. Although several endemic species exist there, they are all Quarternary ones. (2) Tarim Basin It is surrounded by mountains in the south, north and west with Taklamakan desert at its central part. The longest inland river in the world, the Tarim River runs through the basin. It is located deep in the inland, very far from the ocean, with a warm-temperate climate and very little precipitation, and is rather poor in plant species. The tugayi forest is distributed only along the river. With the intensification of aridity halophytes increase. The floristic elements here are very different from those in the Junggar Basin. There are neither ephemeral and ephemeroid plants nor Haloxylon persicum. The species of Calligonum are different from the ones in the Junggar Basin. The Ammopiptanthus nanus, an endangered species, distributed northwest of Kashgar City, exhibits disjunction with A. mongolica in the Alashan desert. This is the only evergreen shrub genus in our sandy areas, obviously a subtropical relict, which may prove that there already xerophytes in the Tertiary period. In western Tarim there are Middle Asian elements, such as Populus euphratica. In the eastern part of Tarim there exist elements of the Mongolian flora , such as Sympegma regelii. In the Tarim basin there are many endemic species, e.g. Aristida grandiglomis, Caragana polourensis. The relic nature, disjunctions, and endomism may explain that there already existed xerophytes in the Early Tertiary period. There are either endemic elements or elements of Mediterranean, Middle Asia and Alashan, which may indicate that even in the Early Tertiary period plants already occurred and new developments took place in the Late Tertiary period in the basin. (3) Tsaidam Basin The basin was a part of the Tethys before the Mesozoic era and became land during the orogenesis. Its flora has evolved from the xerophytic tropical flora along the southern coast of the Tethys. The present-day dominant species of lowland and shifting sands such as Tamarix hispida, Nitraria sibirica, Haloxylon ammodendron, are similar to those in the Tarim Basin. There are only a few endemic species in the Tsaidam Basin, such as Salsola zaidamica, Calligonum zaidamense, that all originated in the Quarternary species. Some Mongolian elements had penetrated the eastern part. (4) Alashan Desert It lies deep in our hinterland and is abundant in endemic genera,such as Potaninia, Tetraena, Stilpnolepi, Elachanthemum, and oligotypic genera, such as Gymnocarpos, Cornulaca, Cynomorium, Pugionium, Ammopiptanthus, which reflects its ancient nature. Furthermore, there are 20-odd endemic species, such as Ephedra rhytidosperma, Synstemon petrovii Which have very narrow area, and they are all ancient in origin. The presence in the desert of these monotypic and oligotypic genera, and endemic species may prove that in the Tertiary period there were already xerophytic plants. Owing to the less influence of ingression and glaciation on the flora of this region more ancient elements could be preserved. However there have also been new developments during the Quarternary period. For example, certain species of Calligonum and Nitraria are newly-developed ones. (5) Eastern sandy areas in the steppe zone These areas obtain greater influence of the ocean; they have more precipitation, abundant floristic elements and lower topography. After the glaciation in the Tertiary and Quarternary periods plant species from several distribution centres, Mongolia, Europe, Middle Asia, East Asia, and North China, migrated towards this region simultaneously. So, there are no ancient genera here and the floristic elements are all rather young.

The genus Kobresia Willd. , including four sections with 64 species and 5 varieties, belongs to the tribe Cariceae in the family Cyperaceae. The tribe is the most advanced group in Cyperaceae, while the genus is primitive in the tribe. Kobresia is distributed in the temperate to frigid zones of the Northern Hemisphere. All species and varieties, except K. macrocarpa, are found in Asia. They are mainly distributed in the Himalayas and Hengduan Mountains. The genus is especially adapted to frigid habitats, and exists in alpine environments and high latitudes. According to the floristic regionization of Takhtajan (1986), Kobresia is distributed in four regions of the Holarctic Kingdom and one region of the Paleotropical Kingdom. (1) The Circumboreal Region: six species, 8.70% of the total taxa of Kobresia. These species have wide distributions, and two of them, K. bellardii and K. caricina, can be seen almost in the whole range of the genus. (2) The Eastern Asiatic Region: fifty-one taxa, 73.91% of the total taxa, and twenty-two endemic species. This region is divided into the Sino-Himalayan Forest Subkingdom and Sino-Japanese Forest Subkingdom by Wu (1979). Forty-one taxa occur in the former, and twelve of them are endemic. Only eight taxa occur in the latter. (3) The Rocky Mountain Region: three species, 4. 35% of the total taxa, and one endemic species. (4) Irano-Turanian Region: thirty-ninespecies, 56.52% of the total taxa of Kobresia, and six endemic species. According to the scheme of the Chinese floristic division established by Wu, thirty-six taxa exist in the Qinghai-Xizang Plateau Subkingdom, with five endemic. (5) Malesian Region: one species, Kobresia kobresioidea (Kükenth.) Kern, which is primitive in the genus and endemic to the northern mountains in Summatra. In Asia, more than 90% of the total taxa of Kobresia, are found in the Himalayas and Hengduan Mountains. These taxa include the most primitive to the most advanced ones in the genus. The area is not only the center of density, but also the center of diversity of Kobresia, thus it is the center of the distribution of the genus. Kobresia is closely related to the genus Schoenoxiphium, which is confined to Madagascar and southeastern Africa. They might have had a common ancestor in the Gondwanaland. With drifting of the India Plate, the ancestor of Kobresia was brought to Eurasia, and differentiated in the Himalayas and Hengduan Mountains where India met Eurasia. The Indian land mass connected Asia in the early Tertiary, and Kobresia probably began to originate in the same time in the Himalayas. The genus reached its greatest speciation with the lifting of the Himalayas, and dispersed along the mountains in the Northern Hemisphere to Europe and Siberia. From Europe, it arrived at Greenland and eastern Canada. From Siberia, it reached Alaska through the Bering strait, and came down along the Rocky Mountains to Colorado.

The plants of the family Lauraceae are main components of evergreen broadleaved forests in southern China. There are about 20 genera 420 species of the family in China. The authors of this paper made a comprehensive and systematic study on the pollen morphology of the family Lauraceae in China by means of light microscopy and scanning electron microscopy. The paper deals with 22 genera and more than 150 species and describes each genus. They can be distinguished according to the shape of pollen grains, sculpture of exine, existance of tenuity perforation. Based on the shape of pollen grains, they can be grouped into two types: spheroidal type, subspheroidal type. Because of lacking obvious aperture, it is rather difficult to distinguish their polar axis and equator. On the basis of the sculpture and structure of exine distinguished are seven pollen types: 1. Cryptocarya type, the exine smooth or scabrate, without spines: Cryptocarya, Neocinnamomum, etc. 2. Caryodaphnopsis type, the exine without spines, but with dense verrucae on the surface: only Caryodaphnopsis. 3. Litsea type, the exine with distinct spines, without mat-shaped thickening near the base of spines, usually with perforation or tenuity: Litsea, Lindera, Neolitsea, etc. 4. Laurus type, the exine with coarse triangular spines, with longitudinalstreaks on the surface of spines, and with mat-shaped thickening near the base of spines: only Laurus. 5. Persea type, the exine with distinct spines and tenuity or perforation, usually the spines very small and dense, without mat-shaped thickening at the base of spines: Persea, Machilus, Phoebe, Nothaphoebe, Alseodaphne, Sydiclis and Octea. 6. Sassafras type, the exine with or without perforation; spines smooth, with circular mat-shaped thickening at the base of spines: Sassafras, Dehaasia, Cinnamomum and umbellularia etc. 7. Cassytha type, the exine smooth or scabrate, without spines, similar to Cryptocarga type but pollen grains very small: only Cassytha. The pollen morphology of the family Lauraceae was generally thought uniform, little variable and thus difficult to be distinguished. However, our study shows that the shape of pollen grains, the sculpture and structure of exine of the family are diverse. The present paper also discusses the evolutionary trend with taxonomic problems of these genera. Viewed from the pollen morphology, the family Lauraceae has a close relationship with the family Hernandiaceae and is similar to the family Myristicaceae in some respects. Perhaps they are groups developed from the same ancestor. The existence of perforation in the family is reported for the first time.

The components of essential oil in leaves of seven species in Calycanthaceae were analysed by gas chromatography. As a result, nine components were detected and both components and contents vary among species. Based on all the data, Calycanthus was found containing components mostly with more complex structures while those in Chimonanthus, on the contrary, are mostly simple. It indicates that Calycanthus is more primitive than Chmonanthus in phylogeny.

Reexamination of Hilliella warburgii (O. E. Schulz)Y. H. Zhang et H. W. Li and Cochleariella zhejiangensis Y. H. Zhang et R. Vogt indicates that these two species are distinct, especially in fruit, which is hairy in the latter. Thus, we consider that they should be kept separate. C. zhejiangensis is the type of the genus Cochleariella (monotipic).

The monotypic subgenus Acanthoxytropis C. W. Chang of Oxytropis was established in 1988 based on the species O. grubovii Ulzij., which is mainly characterized by solitary flower, coriaceous pods, and keels without beak, while these are typical character of the genus Chesneya Lindl. ex Endl. The present author checked authoritative specimens and assigns it C. macrantha Cheng f. ex H. C. Fu.

Nine species and one variety of Flickingeria are diagnosed, including five new taxa, F. tricarinata, F. calocephala, F. concolor, F. bicolor and F. tricarinata var. viridilamella.