On the basis of biosynthsis, distribution of diterpenoid alkaloids as well as morphological evolution of Chinese species L. (Ranunculaceae), chemotaxonomy of the genus Aconitum is discussed: 1, Subgen. Lycoctonum, containing lycoctonine-type alkaloids and Subgen. Aconitum containing aconitine-type alkaloids, were probably differetiated at the early stage of evolution of the genus Aconitum and evolved respectively in their own ways. 2, In Subgen. Aconitum: (1) Ser. Bullatifolia, containing mainly atisine-, veatchine-type alkaloids, and amino, alcohol and ester base of aconitine-type, and distributed in Hengduan Mountain and Jingsha River valley, where is the centre of modern differentiation of species of Aconitum, is probably a series from which Chinese species of the genus Aconitum were derived; (2) Ser. Inflata, containing mainly aconitine, mesaconitine and bypaconitine, is an advanced group; (3) Ser. Grsndituberosa, containing mainly aconitine and songorine, is related to Ser. Bulatifolia; (4) Ser. stylosa and Ser. volubilia, containing mainly yunaconitine and other anisyl ester alkaloids form another advanced branch. 3, Ser. Tangutica and A. naviculare of Ser. Rotaundifolia, containing atisine and lactone-type alkaloids may be a specialized group in high mountains and have occurred at early stage of evolution of the genus Aconitum. 4, Subgen. Gymnaconitum, containing atisine-type alkaloids and amino alcohol of aconitine type, may als be a specialized group in high mountains. 5, A. franchetii Finet. et Gagnep. mainly containing ester bases of aconitine-typeand closed to A. chasmanthum Stapf, is best placed into Ser. Ambigua.

Pollen grains of 18 species of Pulsatilla in Ranunculaceae distributed in Asia and Europe were examined by LM and SEM, and exine ultrastructure of tricolpate pollen grains of P. chinensis and of pantoporate pollen grains of P. campanella was examined by TEM. Pulsatilla pollen is divided into four major types based on the aperture character, i.e. tricolpate, di- and tricolpate, pantocolpate and pantoporate. The revolutionary trend of pollen types is as follows: tricolpate→pantocolpate→pantoporate. Surface spinulate and perforate. According to density and size of sptnulae and distribution of perforation, the pollen grains of the genus can be divided into two groups. Thin sections of P. chinensis and P. campanella show endexine thickened at colpi and ora. Ektexine consists of a foot layer, a collumellae layer and a continuous, perforate tectum. The columallae layer is thicker than foot layer and tectum. Pollen morphology of Pulsatilla is similar to that of Anemone, but different in the distribution of spinules and perforation. Pollen information supports Wang’s view about systematic arrangment of species of Pulsatilla in China.

Two new species and one nataral hydrid close to Dryopteris chrysocoma (Christ) C. Chr. are found by means of cytological study, which shows that D. chrysocoma circumscribed in the past is not a single diploid in its range, but consists of several cytotypes. D. para-chrysocoma is a sexual diploid with narrowly lanceolate laminae that are almost glandless. The scales on the rachis and pinna rachis are pale brown, longer in length (4-7 mm) and denser. Indusium lacks glands too. The ultimate segments are narrower and separated by arrow spaces. These characters distinguish it from D. chrysocoma. D. zinongii is a sexual tetraploid. It is recognised by its ovate laminae, sparse, small and dark brown scales on the rachis and pinna rachis (1-2mm in length), broad segments closely adjacent one another and membranous indusia. D. × daliensis is shown to be an apomictic triploid which has rather irregular meiosis. There are some free chromosomes at the first metaphase, some lagging chromosomes and bridges at the first anaphase and some micronuclei in young spores. Some unpaired univalents can even be seen at diplotene. Approximately 14 univalents, 14 bivalents and 27 trivalents were observed at late diakinesis. Although a large number of SMCs were counted, a definite chromosome number has so far proved impossible to be obtained. This is possibly caused by variable pairing of the three genomes and different trivalent numbers formed in each SMC. As a result, generally less than 64 abortive spores are formed in each sporangium, but the sporangium with 32 spores could also be found rarely. All these show that this hybrid may be derived from the cross between a diploid and a tetraploid which have homoeologous genomes. D. × daliensis is morphologically intermediate between D. zinongii and D. paraChrysocoma. in respect to characters such as ovate-lanceolate laminae, brown rachis scales with a dark central stripe, 2-3 mm in length, and abortive spores in unequal size and different shapes etc. In addition, they are often found growing together in Cang Shan, Yunnan. It is therefore reasonable to consider that the latter two are probably the parents of the former. These new cytotypes show the presence of Dryopteris chry-socoma complex which is generally characterized by shell-shaped indusia and glandular fronds. Accoding to the morphology, D. woodsiisora Hayata, D. tenuissima Tagawa, D. alpicola Ching et Z. R. Wang, D. fangii Ching, Fraser-Jenkins et Z. R. Wang and D. pseudochrysocoma Ching etc. should be the members of this complex. In order to clarify the relationships between all the members of D. chrysocoma complex, a great deal of further cytogenetic study, including artificial hybridization and analysis of meiosis in both wild and synthesized hybrids, is required. The author is grateful to Prof. R. C. Ching and Mr. C. R. Fraser-Jenkins of the British Museum (Natural History) for their kind and helpful suggestion, and thank Mr. Q. Xia and Mr. Y. L. Ma for their help in the field work.

This paper reports chromosome number and karyotype analysis of Cycas panzhihuaensis endemic to China. The material was collected from Dukou, Sichuan. It is a diploid species, with 2n=22=2m+4sm+4st+l2t. The karyotype of Cycas panzhihuaensis is different from that of the other species of the genus Cycas, which was known to be 2n=4m+8st+10t. The former is a new karyotype in the genus. The authors briefly discuss karyotype evolution of the genus Cycas in this papar.

The present paper is an extension of my revision of Chinese species of the genus Lysimachia published in 1979 (Acta Phytotax. Sin. 17: 21-53). The area under consideration comprises Burma, Thailand and Indo-China. They are closely associated with southern China geographically and floristcally. However, since Bonati’s account for Lecomte’s Flore Generale De L’Indo-Chine (1930) recorded 11 species, and Fletcher’s enumeration listed 12 species from Thailand (Florae Siamensis Enumeratio 2: 323-325, 1938), there has been no detailed systematic study on this genus of the whole area, although many new species have been described and published in different journals. During this study, I have had an opportunity of studing all the materials in the herbaria Edinburgh, Kew, British Museum (N. H.) and Paris. Thanks to these institutions, I am able to judge the species known to occur in this region and present an up-to-date account with a key for identification of all taxa (25 species, 1 subspecies and 2 varieties) and a brief enumeration of their synonyms and geographical distribution. L. chenii, L. remotiflora are described as new; L. insignis, L. microcarpa and L. prolifera are for the first time reported from this region, and the disused name L. siamensis Bonati is reinstated. Furthermore, some additional descriptions or notes on species previously very incompetely known are also included.

In addition to describing a new species, Cypripedium wumengense, as well as a new variety, C. bardolphianum var. zhongdianense, nomenclatural and taxonomic notes are made on its allies and the division to which they belong. They are ltrge]y found in the Hengduan Mountains in southwestern China, characterized by the absence of bract, havirg lip more or less covered with small wart-like outgrowths, and that as the capsule matures the scape becomes much elongated. Six species of this group have hitherto been reported, of which, however, C. ebracteatum and C. nutans are regarded here as conspecific with C. fargesii and C. bardolphianum respectively. Thus, including the new taxa described here, it composes five species and one variety: C. bardolphianum W. W. Sm. et Farrer (var. bardolphianum and var. zhongdianense S. C. Chen), C. micranthum Franch., C. fargesii Franch., C. margaritaceum Franch. and C. wumengense S. C. Chen. They are all grouped here into the same section, Sect. Trigonopedium (Franch.) Pfitz., the oldest legitimate name of this group in the rank of section.