Arceuthobium (Viscaceae) in Mexico and Guatemala: Additions and range extensions

Three new dwarf mistletoes are described:Arceuthobium globosum subsp.grandicaule (Mexico and Guatemala),A. aureum subsp.aureum (Guatemala) andA. aureum subsp.petersonii (Chiapas, Mexico).Arceuthobium guatemalense is recorded for the first time in Mexico. Significant range extensions are recorded forA. abietisreligiosae, A. divaricatum,A. gillii subsp.nigrum, andA. rubrum. New hosts are reported for several taxa. Nineteen members of the genus are presently known from Mexico, and three (possibly four) from Guatemala. Chromosome counts are reported for the first time for 3 taxa.     

Three new species of Cobaea (Polemoniaceae)

Revisionary work has revealed three new species ofCobaea:Cobaea flava of northern Peru,C. paneroi of central Mexico, andC. rotundiflora of Guatemala and extreme southeastern Mexico.Cobaea flava is most similar toC. campanulata and differs mainly in its pedicel pubescence, corolla coloration, and stamen position.Cobaea paneroi is among the large-flowered species (theCobaea scandens group) but is easily distinguished from these by its long-acuminate calyx segments.Cobaea rotundiflora most closely resemblesC. triflora. It differs mainly in its corolla coloration and wider, pubescent calyx segments.     

Carex hermannii (Cyperaceae), a new species from Mexico,with comments on related species at high altitudes in middle America

Carex hermannii, a new species known only from a few populations on large volcanic mountains on the Puebla-México state border, central Mexico, is described, illustrated and compared with its nearest relative,C. cuchumatanensis of Guatemala. Both these species have been confused until now with the more distantly relatedC. endlichii. Morphological comparisons ofC. hermannii, C. cuchumatanensis andC. endlichii confirm the distinctiveness of these species.     

Novae Gesneriaceae neotropicarum VI: five new Gesneriaceae from northwestern South America

Columnea chrysotricha, C. cuspidata (bothColumnea sect.Collandra), andGasteranthus recurvatus are described from Colombia;C. sulcata (Columnea sect.Collandra) from Ecuador and Colombia; andDrymonia anisophylla from the Amazonian lowland rain forests of Brazil, Colombia, Ecuador, and Peru.     

Cardamine L. sect.Macrophyllum O. E.Schulz (Cruciferae Juss.) in the Asian Territory of the Soviet Union A morphological,anatomical and phylogenetical study with taxonomic revision

Based on the study of herbarium material, a critical taxonomic account has been provided onCardamine sect.Macrophyllum (Cruciferae) from the Asian territory of the Soviet Union. Different morphological characters were examined but special attention was paid to flowers, nectar glands, pollen grains, fruits and seeds, followed by the anatomical studies of fruits and seeds. 8 species have been recognized which are arranged in 2 subsections underCardamine sect.Macrophyllum viz. 1.Macrophyllae (C. leucantha, C. tomentella, C. macrophylla andC densiflora) and 2.Prorepentae (C. schinziana, C. yezoensis, C. amareaformis andC. prorepens). Phylogenetic trend also has been traced out suggesting preliminary centres of divergency and polymorphism of the treated taxa.     

Nuclear DNA content variation within the genusTaraxacum (Asteraceae)

Nuclear DNA content was estimated using flow cytometry in 13 sections represented by 18 species of the genusTaraxacum using propidium iodide as the DNA stain. Investigated plants represented diploid, triploid and tetraploid species from sections considered both primitive and advanced, i.e.,T. sect.Dioszegia, Piesis, Glacialia, Mongolica, Scariosa, Obovata, T. pyrenaicum group,T. sect.Coronata, Palustria, Taraxacum (=Crocea),Kashmirana, Ruderalia andErythrosperma. Estimated nuclear 2C DNA content ranged from 1.74 pg in diploidT. linearisquameum (T. sect.Ruderalia) to 6.91 pg in tetraploidT. albidum (T. sect.Mongolica), demonstrating 3.97-fold variation. The lowest monoploid genome size 1C_x=0.87 pg was recorded inT. linearisquameum (T. sect.Ruderalia) together withT. brachyglossum (T. sect.Erythrosperma), and the highest one (1.73 pg) was recorded inT. albidum (T. sect.Mongolica), giving a 1.99-fold difference in the genus. No significant differences in genome size were observed withinT. sect.Ruderalia, similarly no intraspecific variation was observed inT. paludosum (T. sect.Palustria) andT. serotinum (T. sect.Dioszegia). These results indicate a high intraspecific stability of the trait. Preliminary comparisons of genome size in species/sections considered to be close relatives were made. These data give tentative additional evidence for the close phylogenetic relationship between sectionsPalustria andPiesis and against the close relationship between sectionsPiesis andDioszegia.     

New taxa and combinations in Siphonoglossa (Acanthaceae)

As presently known, the genusSiphonoglossa can be divided into two “subgenera,” one of which is here divided into two sections,Pentaloba andSiphonoglossa. Two new species are described from a locality in Durango, Mexico :S. durangensis in sect.Siphonoglossa andS. linearifolia in sect.Pentaloba. Three other species are transferred intoSiphonoglossa:S. canbyi from northeastern Mexico;S. buchii from Haiti and the Dominican Republic andS. incerta from southern Baja California, Mexico.     

Two Distinct Triatoma dimidiata (Latreille, 1811) Taxa Are Found in Sympatry in Guatemala and Mexico

Approximately 10 million people are infected with Trypanosoma cruzi, the causative agent of Chagas disease, which remains the most serious parasitic disease in the Americas. Most people are infected via triatomine vectors. Transmission has been largely halted in South America in areas with predominantly domestic vectors. However, one of the main Chagas vectors in Mesoamerica, Triatoma dimidiata, poses special challenges to control due to its diversity across its large geographic range (from Mexico into northern South America), and peridomestic and sylvatic populations that repopulate houses following pesticide treatment. Recent evidence suggests T. dimidiata may be a complex of species, perhaps including cryptic species; taxonomic ambiguity which confounds control. The nuclear sequence of the internal transcribed spacer 2 (ITS2) of the ribosomal DNA and the mitochondrial cytochrome b (mt cyt b) gene were used to analyze the taxonomy of T. dimidiata from southern Mexico throughout Central America. ITS2 sequence divides T. dimidiata into four taxa. The first three are found mostly localized to specific geographic regions with some overlap: (1) southern Mexico and Guatemala (Group 2); (2) Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica (Group 1A); (3) and Panama (Group 1B). We extend ITS2 Group 1A south into Costa Rica, Group 2 into southern Guatemala and show the first information on isolates in Belize, identifying Groups 2 and 3 in that country. The fourth group (Group 3), a potential cryptic species, is dispersed across parts of Mexico, Guatemala, and Belize. We show it exists in sympatry with other groups in Peten, Guatemala, and Yucatan, Mexico. Mitochondrial cyt b data supports this putative cryptic species in sympatry with others. However, unlike the clear distinction of the remaining groups by ITS2, the remaining groups are not separated by mt cyt b. This work contributes to an understanding of the taxonomy and population subdivision of T. dimidiata, essential for designing effective control strategies.     

Three new species of Cuphea (Lythraceae) from Mexico

Described as new areCuphea flavovirens (sect.Heterodon), C. dibrachiata (sect.Leptocalyx), andC. ownbeyi (sect.Diploptychia).     

Acht neue Arten der GattungDianthus (Caryophyllaceae) aus dem Gebiet der Flora Iranica

Dianthus nangarharicus sp. n. (sect.Leiopetali) from E. Afghanistan;D. harrissii sp. n. (sect.Dentati) from N. Pakistan to W. Tibet,D. hyrcanicus sp. n. (sect.Dentati) from N. Iran. Five further new species from Iran belong to sect.Fimbriati:D. binaludensis (close toD. paghmanicus),D. jacobsii (close toD. crinitus andD. orientalis),D. longivaginatus (similar toD. fragrans),D. mazanderanicus andD. agrostolepis (both close toD. orientalis subsp.Gorganicus).     

Dragma Hippomanicum II: Astragali Novi Peninsulares Moraniani

Three new species are described from Estado Baja California, Mexico:A. (sect. Trichopodi)oxyphysopsis;A. (sect. Inflati)sanctorum; andA. (sect. Inflati)moranii.     

Two new species of Dioscorea (Dioscoreaceae) from Peru

Two new species ofDioscorea,D. gentryi (subgen.Helmia sect.Monadelpha) andD. andromedusae (subgen.Helmia sect.Centrostemon) from Peru, are described and illustrated.     

Toward a census of genus Mimosa (Mimosaceae) in the Americas: a new species from Mexico (Baja California Sur) and two from planaltine Brazil (Goiás, Minas Gerais)

Three new species of Mimosa are described: M. (sect. Batocaulon) epitropica Barneby & León de la Luz from Mexico (Baja California Sur); and two from planaltine Brazil, M. (sect. Habbasia) bispiculata Barneby and M. (sect. Mimosa) demissa Barneby. The affinity of each is discussed, and all are illustrated.     

Two new mimosaceous trees from the American Tropics

Piptadenia (sect.Pityrocarpa)leucoxylon is described from the lower Orinoco basin in Venezuela, andPithecellobium (sect.Samanea)foederale from Distrito Federal, Brazil. Figures, diagnoses, and discussion of kinship are presented for each.     

Sporothrix globosa,a pathogenic fungus with widespread geographical distribution

Sporothrix globosa, reported from the USA, Europe, and Asia, is a recently described pathogenic species morphologically similar to Sporothrix schenckii. In this study, the phylogenetic affinities of 32 clinical and environmental isolates morphologically identified as S. schenckii, from Mexico, Guatemala, and Colombia, were assessed by cladistic analysis of partial sequences of the calmodulin gene using the maximum parsimony and neighbor-joining methods. The study revealed that one out of 25 isolates from Mexico (4%), one out of three isolates from Guatemala (33.3%), and two out of four isolates from Colombia (50%) belonged to S. globosa, while the other isolates belonged to S. schenckii sensu stricto. This is the first record of S. globosa from Mexico, and Central and South America.