Abstract Androsace L. consists of more than 100 species distributed mainly in northern temperate areas. This genus, typically characterized by having small flowers with a constricted corolla throat, was subdivided into six sections: sect. Samuelia Schlechtd., sect. Mirabiles (Hand.Mazz.) Yang & Huang, sect. Androsace, sect. Chamaejasme Koch., sect. Aizoidium Hand.Mazz., and sect. Orthocaulon Hand.Mazz. In this genus, the species with cushion-like growth belong to sect. Chamaejasme occurring in alpine habitats. There are other three small genera in the tribe Androsaceae. Pomatosace Maxim., with only one species, P. filicula Maxim., endemic to Qinghai-Tibetan Plateau, is traditionally placed in the subtribe Soldanellinae because of its circumscissile capsules, but other morphological characters and the recently reported evidence from cytology indicate that its affinity is closer with Androsace. Douglasia Lindley has eight homogeneous species in Northern American mountains. Vitaliana Sesler, with only one species in the European Alps, is usually considered a congener of Douglasia. These four genera, morphologically similar in having small flowers with a constricted corolla throat and “Androsace pollen”, referred here as “Androsace group”, are disjunctly distributed from the Qinghai-Tibetan Plateau, to Central- and Northern-Asia, Europe and North America. It is an ideal group to elucidate the origin and dispersal patterns of the Northern Hemisphere flora, which has a distribution center in the eastern Qinghai-Tibetan Plateau and the Hengduan Mountains. In addition, the habits of this group range from annuals to rosette perennials and cushion-like perennials. The cushion-like species are disjunctly distributed in the central Qinghai-Tibetan Plateau and European Alps mountains. Further studies are needed to determine whether they are closely related to each other or it is only the result of convergent evolution under the habitat pressure selection in separate sites. We firstly reported cpDNA trnL-F, nrDNA ITS sequences respectively or both for 29 populations of 14 species in Androsace and Pomatosace mainly from the central Qinghai-Tibetan Plateau. A phylogeny was further constructed for these species, and those distributed in Europe and North America in “Androsace group” and related genera in Primulaceae based on newly reported sequences and those downloaded from GenBank. Phylogenetic inferences indicated that the four genera in “Androsace group” form a well-supported monophyletic clade. Two main clades were discovered in the “Androsace group”: a wholly Androsace clade, and the other comprising Pomatosace, Douglasia, Vitaliana and nine Androsace species in all analyses. The grouping and position of three species of sect. Samuelia and two species of sect. Androsace varied according to the analyses of the different datasets, trnL-F, ITS or a combination of them. The biogeographical mapping of species distribution revealed that the basal species of each clade sited in southeastern China and the eastern Qinghai-Tibetan Plateau, which obviously supports the origin area hypotheses for “Androsace group” based on morphological studies. From the eastern Qinghai-Tibetan Plateau multiple lineages spread to and colonized Europe in different ages. The crude timing based on ITS sequence differentiation indicated a recent diversification of “Androsace group” within Miocene of the Tertiary. The cushion-like species evolved independently in Asia and Europe. The origin and diversification of cushion-like species in the Qinghai-Tibetan Plateau might be earlier than those in Europe. Their occurrence in the Qinghai-Tibetan Plateau area might be correlated with the large-scale uprising of the plateau and the mountains building since Miocene. But the appearance of the cushion-like species in Europe might result from the fast habitat isolation due to the climate oscillation and the cycles of developing and retreating of the ice sheet in the Northern Hemisphere during the Quaternary. The large-scale colonization of cushion-like Androsace species in the Qinghai-Tibetan Plateau probably occurred in the late Holocene when the global climate re-cooled after the end of glacial cycles. The intraspecific genetic differentiation in some species might partly reflect their retreat and re-colonization in the Qinghai-Tibetan Plateau area during the climate oscillation.

Microsporogenesis and pollen ontogeny in Cycas elongata (Leandri) D. Y. Wang were studied to amass additional information on the reproductive biology of cycads and to provide some data for further studies on the factors causing the endangerment of this species. This species tends to initiate the male cones in middle or late May. The microsporophylls bear their microsporangia on the abaxial surface, and 3-5 microsporangia seem to be arranged radially into a sorus with a stalk. The microsporangium wall comprises one epidermis, four to five middle layers, and a tapetum. The tapetum may be derived from the outer layer of mature sporogenous tissue and conforms to secretory type. In the middle of June the microspore mother cells are produced and immediately enter into meiosis. The cytokinesis in the later stage of meiosis is both simultaneous and successive, a phenomenon observed even in the same microsporophyll. Following meiosis, the nuclei of microspore mother cells divide into four to form tetrahedral, isobilateral, tetragonal and occasionally linear tetrads in late June. Subsequently the microspores are released from tetrads. With the development of pollen, the microspores then undergo two asymmetric mitosis to form mature pollen consisting of three cells, i.e., a tube cell, a generative cell and a prothallial cell. Pollen further develops and is dispersed through the dehiscence of the sporangium in late July. In addition, both starch grains and callose have a regular dynamic distribution during the course of microsporogenesis and pollen ontogeny. The phenomenon that the cytokinesis at the later stage of meiosis in microsporogenesis is both simultaneous and successive has not been previously reported in any other cycads, even in other gymnosperms, and thus may have systematic significance and developmental implications.

Pollen morphology of nine species in Koenigia L. from China was examined under light microscope (LM) and scanning electron microscope (SEM). The pollen grains are 7(-8)-zonocolpate， pantocolpate， or pantoporate in aperture， spheroidal in shape， 17.0-32.5 μm in diameter (including the length of spinules). The ornamentation of exine is prominently spinulose. Based on their features of apertures and exine sculpturing, the pollen grains can be divided into three types， i.e., Delicatulum-type， Forrestii-type and Koenigia-type. The Delicatulum-type is characterized by having 7(-8)-zonocolpate aperture, imperforate tectum and prominently spinulose exine ornamentation. Pollen grains of this type occur in one species， K. delicatula （Meisn.） Hara. The Forrestii-type is characterized by having 12-pantocolpate apertures, imperforate tectum and prominently spinulose exine ornamentation. Pollen grains of this type occur in two species， K. forrestii (Diels) Měsíek & Soják and K. nummularifolia (Meisn.) Měsíek & Soják. The Koenigia-type is characterized by having 15-, 20（-30）-pantoporate apertures, imperforate tectum and prominently spinulose exine ornamentation. Pollen grains of this type occur in six species，K. cyanandra (Diels) Měsíek & Soják，K. fertilis Maxim.，K. hubertii (Lingelsh.) Měsíek & Soják，K. islandica L., K. nepalensis D. Don and K. pilosa Maxim. The present results show that the pollen morphology in Koenigia is of important systematic value. The generic status of Koenigia is supported; Polygonum nummularifolium and P. forrestii may be better transferred to the genus Koenigia from Polygonum sect. Aconogonon Meisn., while P. cyanandrum, P. delicatulum, P. fertile, P. filicaule, P. hubertii, P. pilosum transferred to the genus Koenigia from Polygonum sect. Cephalophilon Meisn.

Athyriaceae is a large and complex fern family. Molecular phylogenetic analyses have shown the family is a natural taxon. Its subdivision into three subfamilies based on chromosome numbers is not supported by molecular evidence. The family is re-divided into five subfamilies according to morphological and molecular characters: Cystopterioideae, Athyrioideae, Deparioideae, Diplazioideae, Rhachidosoroideae.

Paralagarosolen fangianum Y. G. Wei, a new genus and species of Gesneriaceae from Guangxi, China, is described and illustrated. Paralagarosolen Y. G. Wei is closely related to Lagarosolen W.　T. Wang in having corolla tube cylindric, not swollen, and stigmas 2, but differs by having leaves sometimes peltate at base, cyme with only one flower, corolla lobes rounded-obtuse at apex, and capsule broadly ovoid-ellipsoid.

Wentsaiboea renifolia D. Fang & D. H. Qin, a new genus and species of Gesneriaceae from Guangxi, China, is described and illustrated. This genus is similar to Dolicholoma D. Fang & W. T. Wang in the shape of stigma, but differs by having leaves reniform, palmately nerved and base cordate, corolla obliquely campanulate, corolla lobes rounded, and both stamens and staminodes adnate to corolla tube near base. It is also similar to Chiritopsis W. T. Wang in the habit, but differs by having leaves palmately nerved, corolla tube campanulate and abaxially swollen, and stigma hippocrepiform.

A new species of Gesneriaceae, Hemiboea rubribracteata Z. Y. Li & Yan Liu, is described from Guangxi, China. The new species is similar to H. cavaleriei Lévl. in its leaf form, but differs by its robust and rigid stem, red involucre, longer calyx lobes, corolla white and glabrous outside, lower lip of corolla 3-lobed to middle. Key words Hemiboea, Hemiboea rubribracteata Z. Y. Li & Yan Liu, Gesneriaceae, new species, Guangxi, China.

Abstract Five new species and one new variety of Carex from Zhejiang, China are described and illustrated. They are C. tianmushanica (sect. Mitratae), C. pseudotristachya (sect. Mitratae), C. densipilosa (sect. Lageniformes), C. austrozhejiangensis (sect. Rhomboidales), C. chaofangii (sect. Rhomboidales), and C. longerostrata C. A. Mey. var. exaristata (sect. Laxiflorae).

A new species of Alseodaphne in the Lauraceae, A. huanglianshanensis H. W. Li & Y. M. Shui, is described and illustrated. It was collected from an alt. 840-1300 m tropical broad_leaved secondary forest on the Huanglianshan Mountain, SE Yunnan, China. In habit, the new species is very similar to A. yunnanensis Kosterm. from the same area, but differs by having leaves narrower, oblong or oblanceolate_oblong, 5-13×(0.8-)1.2-2.8 cm, almost not foveolate on both surfaces, peduncles and fruit stalks glabrous and densely greyish white verruculose. The new species is also very similar to A. hainanensis Merr., but differs by having leaves oblong or oblanceolate_oblong, chartaceous, acute or acuminate at apex, hardly foveolate on both surfaces, glabrous, lateral veins 7-8, fruit stalks 5-7 mm long, densely covered with greyish white linear verrucae. Key wordsAlseodaphne, Alseodaphne huanglianshanensis H. W. Li & Y. M. Shui, Lauraceae, new species, Yunnan, China.

Pseudochirita guangxiensis (S. Z. Huang) W. T. Wang var. glauca Y. G. Wei & Yan Liu, a new variety of the Gesneriaceae from Guangxi, China, is described. It differs from the typical one, var. guangxiensis by having leaves subentire or with only inconspicuous obtuse serrations, stem and leaves densely adpressed tomentose, and corolla sparsely glandular puberulous outside.

A new combination, Plantago fengdouensis (Z. E. Zhao & Y. Wang) Y. Wang & Z. Y. Li, is proposed based on P. erosa Wall. var. fengdouensis Z. E. Zhao & Y. Wang. This species is similar to P. cornuti Gouan in the plant becoming black when dry and in having relatively large seeds, but differs by having leaves dentate or pinnately incised, 3(5)-nerved, bracts triangular-ovate, corolla lobes narrowly triangular, capsules fusiform-ellipsoid, circumscissile near the middle, and seeds longitudinally 1-grooved on the ventral side. P. fengdouensis belongs to Plantago L. subgen. Plantago, which is characterized by having corollas glabrous, filaments adnate near corolla base, and cotyledons parallel to the ventral side (i.e. hilum face). It is a highly restricted species in distribution, occurring only on two islets in Fengdu County and Zhong Xian County within the Three-Gorges Dam Area.

The revision of the family Apiaceae (Umbelliferae) for the Flora of China has demonstrated the need to formally publish the following 12 nomenclatural novelties: Acronema minus (M. F. Watson) M. F. Watson & Z. H. Pan, A. brevipedicellatum Z. H. Pan & M. F. Watson, Angelica sinensis var. wilsonii (H. Wolff) Z. H. Pan & M. F. Watson, Harrysmithia franchetii (M. Hiroe) M. L. Sheh, Heracleum candicans var. obtusifolium (Wall. ex DC.) F. T. Pu & M. F. Watson, Hydrocotyle hookeri ssp. chinensis (Dunn ex R. H. Shan & S. L. Liou) M. F. Watson & M. L. Sheh, H. hookeri ssp. handelii (H. Wolff) M. F. Watson & M. L. Sheh, Libanotis grubovii (V. M. Vinogradova) M. L. Sheh & M. F. Watson, Ligusticum likiangense (H. Wolff) F. T. Pu & M. F. Watson, L. nematophyllum (Pimenov & Kljuykov) F. T. Pu & M. F. Watson, L. nullivittatum (K. T. Fu) F. T. Pu & M. F. Watson, Pleurospermum bicolor (Franch.) C. Norman ex Z. H. Pan & M. F. Watson. In addition, a lectotype is designated for P. govanianum (DC.) Benth. ex C. B. Clarke var. bicolor Franch. (P. bicolor).

Five species and two varieties in the genus Rhododendron from Guangdong, Guangxi and Sichuan, namely R. chunienii Chun & Fang, R. dentampullum Tam, R. gonggashanense W. K. Hu, R. polyraphidoideum var. montanum Tam, R. subenerve Tam, R. subenerve var. nudistylum Tam, and R. viscigemmatum Tam, are reduced to synonymies. R. shimianense Fang & P. S. Liu is treated as a form of R. lutescens Franch., and thus a new combination, R. lutescens Franch. f. shimianense (Fang & P. S. Liu) Y. Y. Geng, is proposed.

Based on a study of the type specimen of Pellionia pauciflora W. T. Wang and many specimens of P. radicans (Sieb. & Zucc.) Wedd., P. pauciflora is regarded as a new synonym of P. radicans. Key words Pellionia, Pellionia radicans (Sieb. & Zucc.) Wedd., Pellionia pauciflora W. T. Wang, new synonymy.

Close examination of the type material of Podocarpium lancangense Y. Y. Qian has shown that this species is indistinguishable from Hylodesmum podocarpum (DC.) H.　Ohashi & R. R. Mill ssp. podocarpum, and thus is reduced to synonymy herein.

In accordance with the International Code of Botanical Nomenclature, the name Tutcheria spectabilis Dunn (1908) has priority over the later name Tutcheria championii Nakai (1940) which is illegitimate, despite the fact that the latter name has been used in some recent Chinese floras.