Species Of Subgen Research Articles

Molecular phylogenetic analyses and systematics of the genus Saussurea and related genera (Asteraceae, Cardueae)

AbstractThe phylogenetic relationships of the genus Saussurea DC. and Hemistepta lyrata Bunge were analyzed using the nuclear ribosomal ITS and chloroplast matK gene. Phylogenetic analyses revealed that Saussurea ceratocarpa Decne. of subg. Jurinocera (Baill.) Lipsch. and the species assigned to sect. ,Elatae Hook. f. of subg. Saussurea were separated from all other members of the genus Saussurea. The species of subgen. Jurinocera and subgen. Saussurea sect. Elatae form a monophyletic unit along with a group including genus Jurinea Cass. The species of subg. Jurinocera and sect. Elatae share 4–5­gonal cypselas and apical pericarpal crowns bearing sharp horns or sharp teeth. The Saussurea s.s. group is comprised of representatives of six sections of the subg. Saussurea and morphologically distinctive subgenera [Amphilaena (Stschegl.) Lipsch., Eriocoryne (DC.) Hook. f., and Theodorea (Cass.) Lipsch.]. Two frigid­adapted forms, the “snowball plants” of subg. Eriocoryne and the “glasshouse plants” of subg. Amphilaena, were confirmed as members of Saussurea s.s. Hemistepta lyrata and Saussurea s.s. show a close sister relationship, which is supported by the pappus dimorphism involving free, short, scabrid outer bristles or tiny outer scales and basally connate in a ring, with much longer, plumose inner bristles.

The Genus Canthium (Rubiaceae: Vanguerieae) in Tropical Africa

The genus Canthium subgen. Canthium is discussed and recognized as occurring in tropical Africa; three additional tropical African subgenera are recognized: subgen. Bullockia (Bridson 1987), subgen. Afrocanthium and subgen. Lycioserissa (both Bridson 1991), the latter two being revised here. A key is provided to include the genera previously segregated from Canthium (Bridson 1985, 1986, 1987, 1987a) and the tropical African subgenera of Canthium. One new combination at subspecific rank is made, and one new variety described in subgen. Canthium, 3 new species and 1 new subspecies described in subgen. Afrocanthium, and 1 new subspecies described in subgen. Lycioserissa; one new name is provided for a species unplaced subgenerically. Keys are included for the species of subgen. Afrocanthium and subgen. Lycioserissa. Distributions are given and citations included for new taxa. A complete list of all African epithets in Canthium and Plectronia with their current position is appended (Appendix 2).

SPORE MORPHOLOGY OF ANEMIA, MOHRIA, AND CERATOPTERIS (FILICALES)

Spores of the ferns Anemia and Mohria (Schizaeaceae) and Ceratopteris (Pteridaceae) are surveyed with light microscopy and scanning and transmission electron microscopy. In each genus the spores are trilete with radially symmetrical exine sculpture comprising three sets of parallel or near‐parallel muri. Anemia has six spore types. One is reticulate (A. wrightii‐type), and the other five types have either cicatricose or canaliculate sculpture that reflect a basic form, i.e., three mural sets that have mutual anastomoses in each radial region. The cicatricose A. mexicana‐ and the canaliculate A. dregeana‐types represent the simplest expressions of this pattern. Specializations include cicatricose, auriculate (A. raddiana‐type) and canaliculate, ornate (A. oblongifolia‐, A. phyllitidis‐types). Exine structure is homogeneous or differentially microporate; the enveloping two‐layered perine has granulate structure and a granulate to spiculate and/or pitted surface. Mohria spores have a stratified, granulate to rugulose perine and cicatricose exine sculpturing consistent with the A. mexicana‐type pattern, but the muri are hollow. The canaliculate spores of Ceratopteris differ from those of Anemia and Mohria in that the three mural sets are discrete and separated from each other by a stria in each radial region; exine structure is homogeneous and the thin perine is granulate. Within Anemia the A. raddiana‐type is exclusive to subgen. Coptophyllum and the A. oblongifolia‐ and A. phyllitidis‐types to subgen. Anemia. Three spore types are shared by two subgenera; i.e., A. wrightii‐ and A. mexicana‐types in Coptophyllum and Anemirhiza, and the A. dregeana‐type in Anemirhiza and Anemia. Spore polymorphism is indicated in several species of subgen. Anemia, and smooth immature spores are recorded from all three subgenera.

On the Status of Artemisia dubia Wall. ex Bess. and A. myriantha Wall. ex Bess. (Compositae)

Summary. The nomenclature and taxonomy of two very confused species, Artemisia dubia Wall. ex Bess. and A. myriantha Wall. ex Bess., are clarified and nomenclatural synonymies are given. The former is shown to be a member of Subgen. Dracunculus (Bess.) Peterm., Sect. Latilobus Y. R. Ling, and the latter to be a species of Subgen. Artemisia, Sect. Viscidipubes Y. R. Ling. Artemisia dubia Wall. ex Bess. and A. myriantha Wall. ex Bess. were based on specimens communicated by the Honorable East India Company and now presumably at Kiev; isotypes of both are in the Wallich Herbarium (K-W) at Kew. The names were first proposed by Wallich and validly published by Besser, who assigned them to Sect. Abrotanum Bess. Since then they have had a chequered history, and re-examination of specimens in the Wallich collection has shown that this confusion stems from a misinterpretation of the specimens by the original author which led him to place them in the wrong section.

4-O-Demethylnotatic Acid, a New Depsidone in Some Lichens Producing Hypoprotocetraric Acid

A new depsidone is shown to be 4-O-demethylnotatic acid by thinlayer chromatographic comparison of its diazomethane O-methylation products with those of the known depsidone notatic acid. The new depsidone was found in 22 of 33 taxa that also produce a related pf-orcinol depsidone, hypoprotocetraric acid. Hypoprotocetraric acid-previously known in Ocellularia, Parmelia, and Ramalina--also occurs in Leptotrema, Phaeotrema, and Thelotrema. In addition, some specimens produced 4-O-methylhypoprotocetraric acid and notatic acid. The depsides that correspond to the four depsidones studied here are all known, and this complete depside-depsidone series can be viewed in terms of possible biosynthetic pathways. Several recently described species of Parmelia subgen. Xanthoparmelia contain hypoprotocetraric acid (Hale, 1971a,b; Kurokawa & Elix, 1971), a compound previously known only in Ramalina (W. L. Culberson, 1967) and Ocellularia (C. F. Culberson & Culberson, 1968). In six of the Parmelia species, an unidentified PDsubstance occurs with hypoprotocetraric acid. The possibility that this new substance might be the depsidone corresponding to the depside norobtusatic acid was suggested by a recent discovery (Kurokawa et al., 1971) of 4-O-methylhypoprotocetraric acid and a depsidone, notatic acid, that corresponds to the depside obtusatic acid. The latter pair of depsidones occur together in a new Australian species, P. notata Kur. Experiments described in the present report prove that the new depsidone accompanying hypoprotocetraric acid is 4-O-demethylnotatic acid. The new depsidone was identified microchemically in hypoprotocetraric acid-containing species of several genera. In Parmelia subgen. Xanthoparmelia, the occurrence of these depsidones and their 4-O-methyl derivatives provides a biogenetically interesting parallel to the depside chemistry of some species in subgen. Parmelia sect. Hypotrachyna. MATERIALS AND METHODS Species containing hypoprotocetraric acid were analyzed by thin-layer chromatography (TLC) according to a standardized method (C. F. Culberson, 1972). Except where otherwise indicated, materials were from DUKE and Us. Chemical Studies on P. weberi Hale and P. notata Kur.-A small sample (0.11 g) of P. weberi (Weber &r Charette 3663) from Mexico was extracted four times with benzene at room 1 This study was supported in part by grant CB-25346 from the National Science Foundation. 2 Department of Botany, Duke University, Durham, North Carolina 27706. 3 Department of Botany, Smithsonian Institution, Washington, D.C. 20560. This content downloaded from 207.46.13.172 on Fri, 07 Oct 2016 06:15:05 UTC All use subject to http://about.jstor.org/terms 78 THE BRYOLOGIST [Volume 76