Clematis sect. Pseudanemone is revised in this paper. Sixteen species，three sub-species，and two varieties are recognized. They are keyed，described，and illustrated in most cases，and classified into three series. Brief taxonomic history and geographical di stribution of the section are given，and its systematic position and origin are discussed. According to the evolutionary trends of certain morphological characters of leaves，sepals，and anthers，the Madagascan ser. Pimpinelli-foliae is considered the primitive group，and the other two series，ser. Villosae and ser. Chryso-carpae，all occurring on the African mainland，the advan

18-26S rDNA loci were mapped on chromosomes in four species of Par is，and the num-ber and position of rDNA sites in these species were compared f or analysis of the distribution of the sites. All the plants were diploids，and t he genome consisted of five chromosomes，A，B，C，D and E. （1）P. polyphylla var. yunnanensis，2n=10=6m+4t. Two18-26S rDNA loci were de-tected on the short arms o f C and D chromosomes;（2）P. forrestii，2n=10=6m+4t. One locus was detected on th e long arm of B chromosome，and also two loci on the short arms of C and D chromosomes;（3）P. axialis. 2n=10=6m（2sat）+4t（2sat）+1-2B. Two loci were detected o n the short arms of C and D chromosomes. One locus was detected in the cell with t wo B-chromosomes（B），but none was detected in that with only one B chromosome， indicating that rRNA gene existed on B chromsome，and an unequal division occurr ed during mitotic cycle of B-chromosomes. （4）P. daliensis，2n=10=4m+2sm+2st+2t. O ne locus was detected on the short arm of D chromo-some. The signals of18-26S rD NA appeared not only in the second constriction but also in the other regions of chromosome. It is noteworthy that one locus was detected in the terminal region o n the short arm of C chromosome in all the four species studied.

The taxonomic position of the monotypic conifer Pilgerodendron uvi ferum，an endemic species in southern South America，has been disputed on the ba sis of phylogenetic analysis using molecular data. These results suggest that P. u viferum is a species of Libocedrus. Phylogenetic analysis using morphological dat a appears to uphold its separate status. Characters of leaf cuticles are investig ated and compared between four related genera including Pilgerodendron and furth er dis-tinctions between these are reported. The merits of these conflicting dat a sets for the taxonomy of the genus Libocedrus s. l. are discussed. It is conclude d that the evidence for a merger of Pilgeroden-dron with Libocedrus is weak and that both morphology and biogeography support the separation of the two genera.

Pollen morphology of38taxa of Loranthaceae from China，and of eigh t taxa from Indone-sia and Australia was examined under light microscope（LM）a nd scanning electron microscope（SEM）. Based on exine ornamentation characterist ics，Loranthaceae can be subdivided into two groups that are consistent with the two tribes in the family: Elytrantheae and Lorantheae. In the tribe Elytrantheae， pollen grains with3-syncolpate aperture and exine of blunt-tipped spines and str iate ornamentation may represent the primitive type while those with diplocolpor ate and diplosyn-demicolpate apertures are of derived nature. In the tribe Loran theae，pollen grains with isopolarity，3-syncolpate apertures，and granulate exi ne ornamentation may represent the primitive type，while those with heteropolari ty，parasyndemicolpate-syndemicolpate，3-colpate and colpate-brevicolpate or por ate apertures，scabrate and indistinctly granulate ornamentation represent the d erived state. Pollen data suggest three basic groups in the tribe Lorantheae acco rding to the aperture and ornamen-tation characteristics: Group I is composed of Dendrophtho，Scurrula，Taxillus，and Tolypanthus;Group II and Group III contain only Helixanthera and Loranthus respectively. Group I is relatively primitive in terms of pollen morphology. Among genera in Group I，there are only insignifican t dif-ferences in pollen morphology between Taxillus and Scurrula，two genera w ith a close relationship;both Group II and Group III are relatively derived in t erms of pollen morphology.

Pennilabium yunnanense S. C. Chen&Y. B. Luo，a new species of Orchidaceae，is described and illustra ted. It is subsimilar to P. acuminatum（Ridley）Holttum，from which it dif-fers by having smaller flowers ca. 3cm across，white petals spotted with dark purple adaxially and fimbriate-tipped side-lobes of the lip.

Stachyurus himalaicus ssp. purpureus Y. P. Zhu&Z. Y. Zhang，a new subspecies of Stachyuraceae from eastern Himalaya，is described. It differs from the typical subspecies，S. hi-malaicus ssp. himalaicus，by having purplish pink to dark purple flowers. The new subspecies oc-curs in Xizang（Tibet）of China，E Nepal，Sikkim，Bhutan，and NE India，usually growing in dense forests at an altitude between2200and3300m.

Strong justifications have been developed for why woody plants should be viewed as mod-el systems in plant biology. The genus Populus possesses many characteristics that are conductive to functional genomic studies，and therefore leads to its emergence as a model system in extrapolating findings in perennial plant species that are different from annual herbaceous plants. With the pro-ceeding of the whole genome sequencing，poplars will be act as a wide reference for functional ge-nomics studies in perennial plant species and will also contribute towards answering some fundamen-tal scientific questions. This paper reviewed the history and progress of the poplar genome studies and the potential keen topics in the future. The contents mainly address on: （1）the somatic genet-ics studies in Populus;（2）the genomics studies carried out in Populus，including genetic map-ping，genome sequ encing，physical map construction，microarray analysis and linkage disequilibri-um analysis;（3）the potential application of the genome information of Populus for facilitating our understanding of some basic scientific questions.