New species of Podandrogyne (Cleomaceae) V. Two distinctive species from Colombia, with notes on floral morphology of the genus

Polyploidy is the most common chromosomal mechanism involved in the evolution of plants. However, the emergence of polyploid individuals does not guarantee the establishment of a new lineage, and the relationship between polyploidy and reproductive biology is therefore relevant. Libidibia ferrea is a legume tree that has diploid and tetraploid populations. In this work we analyse the reproductive biology of the species to verify the degree of reproductive isolation between the two cytotypes. Observations on phenology, floral morphology, biology, and visitors, breeding system, reproductive success and reproductive isolation were made for both cytotypes in two municipalities of northeastern Brazil. Cytotypes differed for all morphometric parameters analysed, with tetraploids exhibiting higher mean values than diploids. Both cytotypes had the same effective pollinators (native bees from the genera Centris and Xylocopa, and the introduced Apis mellifera). However, since stamens of diploids and tetraploids were of different size, it is possible that spatial separation occurs when pollen of each cytotype is deposited on a bee’s body. Diploids were self-incompatible (ISI = 0) and exhibited high fruit-set after intraploidy crossing (20 %), whereas tetraploids were self-compatible (ISI = 0.47) and set only 3.9 % of fruits after intraploidy crossing. Both cytotypes showed low fruit- and seed-set under natural conditions, and there was no fruit-set after crosses between them. Data are discussed in relation to the establishment of polyploids, to the pattern of distribution of the species and to the taxonomic implications. The cytotypes of L. ferrea should be considered as distinct species, since they are reproductively isolated from each other.

Plants meet machines: Prospects in machine learning for plant biology

Arnica fulgens Pursh and A. sororia Greene are sympatric throughout most of their ranges in northwestern United States and adjacent southwestern Canada. These taxa were previously recognized as two morphologically overlapping varieties or not very well separated species. A study of their floral and vegetative morphology, using TAXMAP cluster analyses, foliar flavonoid chemistry, reproductive biology, and ecology indicates that they are distinct species. Studies of reproductive behaviour reveal them to be amphimictic (2n = 38) and self-incompatible. Artificial hybridization experiments between the two species were unsuccessful.

The genus Cuscuta L. are obligate stem parasites, with long, multi- branched, modified thread like stem, attacking an extensive range of host plants. The Cuscuta species has cosmopolitan occurrence and are widely distributed throughout the temperate and tropical zones and colonizers diversity of habitats. Though, Cuscuta spp. is known to affect a number of crop and non-crop species globally, there is limited information on biology, ecosystem and farmers’ knowledge, existence species of diversity and threat to crop production. Furthermore, knowledge on the existence of variation within a species is a prerequisite for developing sustainable management strategies for Cuscuta spp. in a specified agrosystems as well as making decision for comprehensive management practices for the weed. Therefore, the aim of the study was to assess the morphological diversity of Cuscuta Species based on floral morphology in Uasin Gishu County, Kenya. The study was carried out in Uasin Gishu County across the six sub-counties using purposive and convenient sampling design. The study involved Morphological identification by examining Cuscuta species general appearance and the microscopic flower morphology examination. The morphology of the floral characters revealed distinct Cuscuta species from the accessions collected from Uasin Gishu County, Kenya. Concisely, the flowers were microscopically identified to the species level across all the samples and showed that the clusters contained of five petals, five sepals and five stamens. Cuscuta species showed tremendous diversity in Uasin Gishu County with Cuscuta reflexa exhibited wide distribution in the County. Characterization of species provide valuable information for extensive analysis and precise identification of Cuscuta and develop better management and utilization strategies.

This study elucidates the taxonomic affinity of Oropheayunnanensis by considering whether it belongs to Orophea or Alphonsea. Integrating comparative morphological analysis of type and living materials, field investigations, and molecular phylogenetic evidence, we confirm that O.yunnanensis should be transferred to Alphonsea as a distinct species. A new combination Alphonseayunnanensis (P.T.Li) Y.H.Tan & Bin Yang is proposed. The mature floral morphology and fruits of A.yunnanensis are described for the first time based on wild-collected living specimens and recent herbarium collections. Detailed descriptions, color plates, and geographical distribution, and conservation assessments are provided.

Summary. Detailed morphological investigations have shown that the name Dendrobium purpureum Roxb. has been applied at various times to six distinct taxa: D. capituliflorum Rolfe, D. catillare Rchb. f., D. constrictum J. J. Sm., D. kraemeri Schltr., D. morrisonii Schltr. and D. purpureum Roxb. The name D. catillare has itself been misapplied to a species which is here described under the new name D. taveuniense. D. purpureum var. candidulum Rchb. f. is here raised to the level of subspecies. Each taxon is described and illustrated and a key is provided for their identification. Whilst revising section Pedilonum (Blume) Lindl. of the genus Dendrobium Sw., it has become apparent that the name Dendrobium purpureum Roxb. has been applied to material from Sulawesi to Samoa and from Palau to Vanuatu, which varies greatly in both floral and vegetative characters. The nature of this variation indicates that the name D. purpureum has been used for six distinct species. Detailed examination of type material has also shown that the name of one of these species, D. catillare Rchb. f., has itself been misapplied. A new species, D. taveuniense Dauncey & P. J. Cribb, is therefore described. The following account outlines the nomenclatural history, defines the species involved and shows how they differ from each other. The confusion between these seven species has several origins. The scarcity of material from the Moluccas, the type locality of D. purpureum, has led to a poor understanding of that species. Much of the synonymy has been proposed by botanists working on regional floras who did not have access to all type material and who had an incomplete understanding of the related species in other geo- graphical areas. The use of flower colour without reference to floral morphology has probably been a major cause of confusion. Finally, the vegetative morphology of the taxa is quite similar.

Circumscription of Lapeirousia corymbosa , type species of subgenus Paniculata section Fastigiata, previously regarded as comprising three subspecies, is restricted to plants with small blue (or white) flowers with symmetrical white markings, and usually symmetrically disposed stamens. Subsp. fastigiata is elevated to species rank as L. fastigiata, and comprises plants with large yellow, actinomorphic flowers. Lapeirousia azurea , until now included in subsp. fastigiata, is treated as a separate species for plants with large dark blue, zygomorphic, and typically resupinate flowers. Field studies indicate that L. corymbosa subsp. alta is a distinct species, here described as L. neglecta. Floral morphology differs consistently in each species, as do aspects of leaf, capsule and seed morphology. Comparison of seeds in the two sections of subgenus Paniculata shows that species of section Fastigiata are derived in their smaller, reticulate (to rugose), ovoid seeds with a large funicular appendage. Seeds of section Paniculata accord closely with those of the presumed outgroup, Savannosiphon : they are comparatively large, smooth to rugulose and have a small appendage. Lapeirousia neglecta has seeds and chromosome morphology characteristic of section Paniculata , and it is now assigned to that section. The addition of L. neglecta to section Paniculata extends the range of the section from tropical and subtropical Africa to the south-western Cape.

Background: Agave ellemeetiana ( A . sect. Choritepalae ) features soft and “spineless” leaves and occurs in two disjunct and ecologically differentiated populations classified as subspecies. An incidental look at the flowers of A . ellemeetiana ssp. subdentata unveiled that these did not match those of A . ellemeetiana s. str. nor those of sect. Choritepalae .
 Questions: Do these disjunct populations differ in flower and fruit morphology? Do they belong to the same section within Agave ?
 Hypotheses: The floral morphology of populations of Agave ellemeetiana ssp. subdentata from western Oaxaca places this species in A . sect. Inermes , and the set of qualitative and quantitative differences is sufficient to recognize it as a distinct species.
 Studied species: Agave ellemeetiana , Agave pedunculifera .
 Study site and dates: Putla District, western Oaxaca, December 2011 and April 2014.
 Methods: We conducted an alpha-taxonomic study of the Agave ellemeetiana species complex, involving two fieldwork expeditions, review of literature, online images, and herbarium specimens.
 Results: Differences in flower, fruit and vegetative morphology and habitat support the segregation of the populations (from the Putla District, Oaxaca) from the Agave ellemeetiana complex as a new species, A . rosalesii spec. nov. The presence of an evident corolla tube places the proposed taxon close to A . pedunculifera and within A . sect. Inermes .
 Conclusions: The populations from the Putla District are sufficiently distinct in their morphology and ecology to merit recognition as a new species, Agave rosalesii , placed in A . sect. Inermes .
 
 
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Waltheria belizensis J. G. Saunders, a new distinctive Sterculiaceae species known only from Mountain Pine Ridge National Forest Reserve, Cayo District, Belize, and potentially distylous by floral morphology, is described and illustrated. It is placed in section Waltheria L. in the W. cinerescens A. St.-Hilaire alliance by its penicillate stigma and loculicidal capsule with an extensive corneous endocarp. It is closest to the distylous W. petiolata K. Schumann in Martius from Brazil (Rio de Janeiro) by the decomposite inflorescences; the shape, venation, and vestiture of calyces; and the shapes of petal apices and seeds. Waltheria belizensis differs from W. petiolata by leaves with minute, appressed vestiture, revolute teeth margins, and a greater number of lateral veins; corymbiform inflorescences; and a seed less lobed and less pusticulate. The contrasting characters are detailed in a key. Thrum-like pollen of W. belizensis and thrum pollen of confirmed W. petiolata are reported for the first t...

Chemical composition of floral perfumes in Mormodes (Orchidaceae): implications for selective attraction of euglossine bees.

Premna mwadimei (Lamiaceae), a distinct new species from the coastal forests of Kenya, Cha Simba area in Kilifi County, is described here with photographs. It is closely similar to P. chrysoclada and P. tanganyikensis but mainly differs from both by its habit, nature of the older stems, indumentum, leaf shape and floral morphology.

96/04384 Follar uptake of 137Cs from the water column by aquatic macrophytes

96/04388 The greenhouse gas consequences of wasre management — identifying preferred options

Hybridization and systematics of dioecious North American Nymphoides (N. aquatica and N. cordata; Menyanthaceae)

Pseudosasa nanunica, a bamboo endemic to Guangdong and Hunan provinces, China, has a complicated taxonomic history due to lack of information on its floral morphology. It was initially described as a member of Indocalamus, and later successively transferred to Pseudosasa, Arundinaria and Acidosasa by different researchers. With the newly collected reproductive materials, we confirmed that this species is characterized by having branch complement with 1-3 branches per node, branch base appressed to the culm, narrowly trullate culm bud, panicle-like unit of inflorescence of the synflorescence and each floret with three stamens and three stigmas, which match well with the diagnostic characters of Pseudosasa. After comparison with similar congeneric species, we concluded that it is a distinct species of Pseudosasa. A supplementary description on its floral morphology as well as two color plates and a diagram of its synflorescence is also provided.