The genus Hymenoclea (Compositae: Ambrosieae)

Two species are recognized within the genus,H. monogyra Torr. & Grayex Gray andH. salsola Torr. & Grayex Gray. Of these, the fall-floweringH. monogyra is monomorphic and unambiguous. The springfloweringH. salsola, however, is polymorphic and contains elements that have often been segregated as distinct species. Examination of character intergradation and interpretation of morphological variation against the evolution and distributional backgrounds indicate that the latter complex is best treated within three varietal taxa:H. salsola var.fasciculata, with wings of the fruiting involucres appressed and spirally arranged;H. salsola var.salsola, with wings emergent and spirally arranged; andH. salsola var.pentalepis, with wings strongly emergent and whorled.     

The genus Iphionopsis (Compositae - Inuleae)

The new genus Iphionopsis A . Anderb. (Compositae-Inuleae-Inulinae) is described with its two species, transferred from the genus Iphiona Cass., I. rotundifolia (Oliv. & Hiern) A. Anderb. from Ethiopia, Somalia, and Kenya, and I. ilicifolia (Humbert) A. Anderb. from Madagascar. The genus is monophyletic, defined by a number of synapomorphies.     

Revision of the genus philactis (Compositae)

Philactis (Compositae-Heliantheae) is a genus of three species, all of limited distribution. A revision is presented, based upon herbarium specimens and field work. Cytological data are from bud material fixed in the field, and from root tips of seedlings. The basic chromosome number appears to be 14.P. nelsonii andP. liebmannii are tetraploid (2n = 56), andP. zinnioides is hexaploid (2n = 84).     

Chromosome evolution in the genus Mikania (Compositae)

Karyotypic analysis of ten species of the genus Mikania was carried out using Feulgen staining. Species belonging to the following sections were analyzed: Section Thyrsigerae containing M. additicia (2n = 34), M. hemisphaerica, M. lanuginosa, and M. punctata (2n = 36), and Mikania sericea (2n = 42), which adds a new basic chromosome number (x = 21) to the genus and to the tribe Eupatorieae; Section Corymbosae with M. hastato-cordata (2n = 34) and M. involucrata and M. microptera with 2n = 36 chromosomes; Section Spicato-Racemosae with M. sessilifolia, with 2n = 108 chromosomes. One unidentified species with 2n = 34 chromosomes was also analyzed. All the species studied show one large pair of chromosomes with a secondary constriction in the middle region of the long arm. The morphology of this chromosome suggests that it can be considered as a cytological marker for the genus. Because of the distinctive inflorescence types found in the genus Mikania and the high frequency of species with x = 18, a correlation between morphological and chromosomal evolution is discussed. The present study suggests that the basic original chromosome number for the genus is x = 18, from which the others (x = 17, 19, 20, 21) have been derived by aneuploidy to form the observed aneuploid series.     

A taxonomic revision of the genus Perdicium (Compositae -Mutisieae)

In connection with a revision of Gerbera L. nom. cons. in Africa the genus Perdicium L. is revised. The genus includes two species, P. capense L. and P. leiocarpum DC. in the Western Cape Region of South Africa.     

Metastevia (Compositae: Eupatorieae): A new genus from Mexico

A new genus and species from Mexico,Metastevia hintonii, is described. The genus, considered to be closely related to and derived fromStevia, differs in seven morphological features from all known species ofStevia. The reasons for recognizing the new genus are discussed in detail.     

Re-establishment of the genus Prenanthella Rydb. (Compositae: Cichorieae)

Prenanthella is re-established as a genus distinct fromLygodesmia on the basis of morphological, palynological, and chromosomal data. Possible relationships ofPrenanthella to other Stephanomerinae and to the genusCrepis are suggested.     

A Systematic study of the genus Balduina (Compositae,Heliantheae)

The genusBalduina, endemic to the southeastern United States as interpreted here, includes a complex of three species:B. atropurpurea Harper,B. angustifolia (Pursh) Robinson, andB. uniflora Nutt. The first two species have a chromosome number ofn = 18 andB. uniflora hasn = 36. Hybridization experiments demonstrated strong internal reproductive isolating mechanisms. Flavonoid and sesquiterpene lactone data suggest a possible relationship to the tribe Helenieae.     

The control of chiasma frequeney within a polyploid series in the genus Senecio (Compositae)

Chiasma frequency in a polyploid series, and in the hybrids formed within it, are shown to be directly related to ploidy level, and to be independent of the apparent effective synapsis. The observations are related to previous observations and models on the control of chiasma frequency.     

Stephanbeckia plumosa (Liabeae: Compositae): A new genus and species from southern Bolivia

Material from southern Bolivia, recently collected by Stephan Beck, is described as a new genus and species, Stephanbeckia plumosa (Compositae: Liabeae). Both morphological and molecular data place the genus in the broadly interpreted subtribe Paranepheliinae, but clearly distinct from other members. It differs morphologically by its small size, deciduous plumose pappus, lack of paleae, and compressed bicostate achenes. A key to the genera of the Liabeae is provided.     

Embryology of Calenduleae (Compositae)

Microsporangial conditions, macrosporogenesis, embryo sac development and in some species endosperm formation have been studied in 5 species of Dimorphotheca Vaill. ex Mnch, 2 species of Castalis Cass., 16 species of Osteospermum L., 6 species of Calendula L., 1 species of Gibbaria Cass., and 1 species of Chrysanthemoides Tourn. ex Fabr.
The microsporangial wall consists of four different layers of cells. Miocrospore formation is simultaneous. The tetrads are mostly arranged in tetrahedrals. A tapetal periplasmodium develops.
The archespore of the macrosporangium is in most cases 1-celled, sometimes 2-or many-celled. The meiosis gives rise to a linear tetrad. Usually the chalazal macro-spore develops. The embryo sac development is monosporic of the Polygonum type. In a few cases in Dimorphotheca venusta T. Norl. a tetrasporic embryo sac development was observed besides the Polygonum type. Castalis tragus (Ait.) T. Norl. may have a bisporic embryo sac development in addition to the Polygonum type. All the Calendula species develop synergid haustoria. Antipode haustoria occur in Osteospermum sinuatum (DC.) T. Norl. and Chrysanthemoides monilifera (L.) T. Norl. Chalazally situated extra embryo sacs below the ordinary one in Dimorphotheca sinuata DC, D. venusta , and Castalis nudicaulis var. graminifolia (L.) T. Norl. are regarded to be aposporic. Six species have more than three antipodes per embryo sac. The antipodes occasionally become 2-or 4-nucleate.     

Correllia (Compositae: Peritylinae) : A new monotypic genus from southern Chihuahua,Mexico

A new genus,Correllia, and its single species,C. montana, are described from Sierra Mohinora in southwestern Chihuahua, Mexico. The genus belongs in subtribe Peritylinae (Compositae tribe Helenieae) and appears to be most closely related toPerityle.     

中国菊科植物一新归化属--黄菊属

报道了在河北和天津发现的菊科一新记录属和一新记录种,即黄菊属Flaveria Juss.及二齿黄菊F. bidentis (L.) Kuntze,并提供墨线图.黄菊属与万寿菊属Tagetes L.和天人菊属Gaillardia Fouger.近缘,它们的共同特征是花序托无托片;不同点在于黄菊属叶对生或交互对生,常基部连合,头状花序在枝顶聚集成平顶形的伞房状或近球形的复合花序,花黄色,舌状花1(-2),冠毛缺.     

Taxonomy of Platyschkuhria (Compositae)

Platyschkuhria is considered to be a monotypic genus of the subtribe Bahianae. Varietal morphologic variation inP. integrifolia is reported.     

A new species of the South American genus Nassauvia (Compositae: Mutisieae) from Chilean Patagonia

Nassauvia coronipappa Arroyo & Marticorena, from Cerro Donoso in eastern Chilean Patagonia, is described and illustrated. It is distinguished by trifid inner involucral bracts and persistent, brief, laciniate-dentate, crown-like pappus incompletely surrounding summit of the achene. The distinctive pappus may be related to selection, in harsh alpine habitats, against dispersal away from nurse sites.Nassauvia coronipappa belongs to subgenusNassauvia. It is seen as a relict member of an independent line of evolution, whose closest affinities are with sectionNassauvia of that subgenus.