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The floral morphology of Sassafras randaiense (Hayata) Rehder (Lauraceae), a rare species endemic to Taiwan, has never been well documented. Consequently, much confusion exists in taxonomic literature regarding its flower structure and reproductive biology. To clarify these matters, we observed 20 flowering individuals of S. randaiense in their native habitats in the spring of 2007. The inflorescences of S. randaiense are highly reduced panicles to botryoid cymes, with up to 10 such inflorescences clustered subterminally to form an umbel of panicles and/or cymes. Its flowers are bisexual, and its third-whorl anthers are extrorse, structured as a typical hermaphroditic flower of Lauraceae. Our observations also revealed that its flowers are protogynous and flowers in a reproductive shoot alternate their sexual phase synchronously, suggesting the sexual system of synchronous dichogamy. The temporal dioecy imposed by this sexual system may explain why S. randaiense has been variously described as a dioecious, androdioecious, or polygamous species in the past.
Species related to Paspalum denticulatum Trin. are studied systematically, including taxa traditionally placed in the informal group Livida of Paspalum L. The analysis demonstrates Livida to be an artificial group, without characters that delimit it from remaining groups within Paspalum; for this reason, its species are treated as ungrouped within subgenus Paspalum. A total of 11 species are herein described, compared, and analyzed. Paspalum hieronymii Hack., P. jujuyense Zuloaga, P. lividum Trin. ex Schltdl., and P. proliferum Arechav. are maintained as synonyms of P. denticulatum. Paspalum tinctum Chase is here reduced to synonymy under P. hartwegianum E. Fourn. and P. arsenei Chase under P. pubiflorum Rupr. ex E. Fourn. Paspalum pisinnum Swallen and P. trinii Swallen are here treated under the synonymy of P. trichophyllum Henrard. Distribution maps, plates of species not previously illustrated, and SEM microphotographs of the upper anthecia are included, as well as a taxonomic key to differentiate the accepted species.
The Caribbean genus Ginoria Jacq. (Lythraceae) is revised for the first time since a monograph was completed in 1903. Studies of the wood anatomy, vegetative and floral morphology, pollen and seed morphology, and chromosome numbers are summarized for Ginoria and the putatively closely related genera Crenea Aubl., Haitia Urb., Lawsonia L., and Tetrataxis Hook. f. Flowers of G. lanceolata O. C. Schmidt are described for the first time. Ginoria is minimally paraphyletic and possibly polyphyletic. Either Ammannia L./Nesaea Comm. ex Kunth or Lawsonia is sister to Ginoria based on ITS data. Phylogenetic analysis based on morphology finds Ginoria monophyletic only when Haitia is included in the genus. Phylogenetic analysis based on ITS sequences produced a single tree in which G. jimenezii Alain, a rare species from the Dominican Republic, is sister to the rest of the genus and Tetrataxis is nested within Ginoria. The positions of Haitia and Crenea remain to be tested by molecular data. Haitia is placed in synonymy of Ginoria based on the strength of the morphological evidence. Further taxonomic changes are deferred until more complete gene sampling among the putatively related genera is possible. Thirteen species of Ginoria are recognized: one from Mexico, six from Cuba, five from Hispaniola, and one from Puerto Rico and the Virgin Islands. The taxonomic treatment includes a key to the species, taxonomic descriptions, illustrations, and distribution maps. Ginoria sect. Discospermum Koehne is typified by G. curvispina Koehne. Three new combinations, G. buchii (Urb.) S. A. Graham, G. pulchra (Ekman & O. C. Schmidt) S. A. Graham, and G. americana Jacq. var. spinosa (Griseb.) S. A. Graham, are made. Two species are brought into synonymy: G. spinosa Griseb. and G. davisii M. C. Johnst. Evolution of selected characters and biogeography of the genus are briefly examined in a phylogenetic context. The endemic nature and rarity of the majority of species make them highly vunerable to extinction.
This paper presents chromosome data for 130 accessions of 91 species or subspecific taxa representing 26 genera of Neotropical Rubioideae (Rubiaceae). It includes the first chromosome counts for the tribe Perameae, for 11 genera, and for 71 species and subspecific taxa. A survey of the karyological knowledge (chromosome numbers, ploidy levels, chromosome morphology) for Neotropical Rubioideae is given. The relevance of the karyological information for a discussion on relationships and speciation in the Rubioideae is commented on. Possible taxonomic implications of the data are presented.
Previous studies have postulated that the Streptanthus glandulosus Hook. complex (Brassicaceae) originated through gradual range contraction and isolation of populations of an ancestral species distributed in California, United States. Here, we integrate patterns of interfertility, morphology, ITS, and chloroplast DNA (cpDNA) variation to generate a classification system reflective of the phylogeny of this group. As a result, we propose a single species, S. glandulosus, with 10 subspecies, to constitute the complex. Populations of S. glandulosus subsp. glandulosus distributed north of the San Francisco Bay are now divided between two new subspecies, S. glandulosus subsp. arkii M. S. Mayer and subsp. raichei M. S. Mayer, diagnosable through molecular apomorphies, perianth color, and fruit orientation. The name S. peramoenus Greene is synonymized to S. glandulosus subsp. glandulosus and is further lectotypified.
Three monotypic and endemic genera of epiphytic Gesneriaceae (Gesnerioideae, Coronanthereae) occur in temperate rainforests of southern South America. In this article, intraspecific differences in rooted substrate and interspecific variation in epiphytic growth habits among these three Gesneriaceae species were assessed. The presence or absence of plants on the ground and main rooted substrate when growing epiphytically on trees were used to characterize epiphytic growth habits in two old-growth temperate rainforests of northern Chiloé Island (42°30′S) in Chile. An evolutionary interpretation based on reported phylogenies and morphologies within the Coronanthereae is proposed. Two species of Chilean Gesneriaceae, Mitraria coccinea Cav. and Asteranthera ovata (Cav.) Hanst., originate from the forest floor, then climb on trees while maintaining their main roots in the ground, and are classified as secondary hemiepiphytes. The third species, Sarmienta repens Ruiz & Pav., was found exclusively on tree trunks and branches of living and dead trees and thus may be classified as a holoepiphyte. Based on reported phylogenies and biogeographical, ecological, and morphological data, the mechanically independent arboreal habit appears to be the ancestral condition in the Coronanthereae, which in turn gave rise to the climbing habit and finally the holoepiphytic habit. This may be a common evolutionary pathway toward holoepiphytism within other lineages in the Gesneriaceae.
Chromosome numbers and meiotic behavior of 60 individuals of American Paniceae, Poaceae, are provided, including six previously uncounted species: Axonopus andinus G. A. Black (2n = 20), A. iridifolius (Poepp.) G. A. Black (2n = 20), Dichanthelium hebotes (Trin.) Zuloaga (2n = 18), Paspalum geminiflorum Steud. (2n = ca. 20), P. heterotrichon Trin. (2n = 20), and Setaria tenacissima Schrad. ex Schult. (2n = 36). Of the remaining 54 counts, 17 correspond to new ploidy levels in species of Echinochloa P. Beauv., Eriochloa Kunth, Hymenachne P. Beauv., Panicum L., Parodiophyllochloa Zuloaga & Morrone, Paspalum L., and Setaria P. Beauv., and 37 are confirmations of previous reports.