El género Cunila (Lamiaceae, Mentheae) en Argentina

Cunila is an American genus with about 23 species and a disjunctive distribution between the United States of America (from New York State to Texas and Florida) and Central America, and Southern Brazil, south of Uruguay and NE Argentina. Four species of Cunila (C. angustifolia, C. incana, C. microcephala and C. spicata) were recorded for Argentina, with an area of distribution ranging from Misiones to Santa Fe provinces. This contribution is a systematic review of this genus in Argentina, including descriptions, synonymies, new lectotypification, and a key to species. Morphological information and iconography of C. incana and C. spicata are provided. The area of distribution for Cunila microcephala is extended 4 degrees West (ca. 62° Long. W), up to Santa Fe province, Castellanos department.Cunila es un género americano con cerca de 23 especies de distribución disyunta: un área comprende Estados Unidos de América (desde el Estado de Nueva York hasta Texas y Florida) y Centroamérica, y la otra desde el sur de Brasil y Uruguay hasta el noreste de Argentina. Cunila está representado en Argentina por 4 especies que se distribuyen desde Misiones hasta Santa Fe: Cunila angustifolia, C. incana, C. microcephala y C. spicata. Se presenta una revisión sistemática del género en Argentina, se describen las especies con sus sinónimos, se lectotipifican nuevamente los nombres, se presentan mapas de distribución con la ampliación de área para C. microcephala 4 grados hacia el oeste (ca. 62° Long. O) hasta el departamento de Castellanos, provincia de Santa Fe. Se aporta iconografía sobre C. spicata y C. incana, datos micromorfológicos y claves de especies

Dioscorea haumanii Xifreda

Urundel, arroyo NipanpublishedVersio

Natural hybrids in Senecio (Asteraceae): new records from Argentina

Hybridisation is very common within Senecio. It is considered a fundamental mechanism of speciation and also a major feature causing systematic complexity. Morphological features are the preliminary characteristics used to identify hybrids; however this approach is usually not sufficient when this is the case chromosome studies represent a valuable tool for reinforcing the observations. Two natural homoploid interspecific hybrids are reported here: Senecio 6 lulioi M. G. Lo´pez et Xifreda (S. brasiliensis (Spreng.) Less. 6S. grisebachii Baker) and Senecio 6piepaloensis M. G. Lo´pez et Xifreda (S. ragonesei Cabrera6 S. sectilis Griseb.). Classic cytogenetic analysis and pollen stainability were performed to evaluate hybrid origins and to designate the putative parents. S. 6lulioi presented a low frequency of quadrivalents and heteromorphic bivalents, both strong evidences of hybridisation between closely related species. S.6 piepaloensis exhibited a high frequency of meiotic irregularities, and reduced pollen stainability, certain characteristics of hybrids. This analysis is discussed in relation to the role of hybridisation in the evolution of the genus, and its systematic significance.Fil: Lopez, Mariana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Citogenética y Evolución; ArgentinaFil: Wulff, Arturo Federico. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución. Laboratorio de Citogenética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Xifreda, C. C.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Etnobotánica y Botánica Aplicada; Argentin

Anatomía y micromorfología de hojas y tallos de dos cultivares de rosa hybrida l. para flor de corte

199-204Micromorphological and anatomical differences in leaf epidermis and stem xylem of Rosa hybrida `Lovely Red` (LR) and `Rouge Baiser` (RB), commercially grown in Buenos Aires, Argentina, were examined in the lower half of the terminal leaflet of 5-foliate leaves and in the basal part of stem, respectively. Digital images obtained from SEM and a phase contrast microscope were used with this purpose. Epicuticular wax, which was present on both sides of the leaves, was more abundant in LR than in RB. Stomata were only present on the abaxial side; they were 111 and 129 per mm2 in LR and RB, respectively; the number of epidermal cells was 1025 and 822 mm2 in LR and RB, respectively. No significant differences were observed between cultivars. Lovely Red and RB showed 267 and 308 vessels/mm2 stem, respectively, with a total area of 0.87 and 0.64 mm2/mm2 stem, respectively, and a vessel area of 0.33 and 0.21 mm2, respectively, with significant differences between cultivars for vessel and total area (p less or equal than 0.05). As a result, LR showed a smaller vessel number, but they were larger and with a greater total surface area. Therefore, this cultivar might be better than RB for water transport, although more prone to wilting under water stress. Our results complement other studies on cut rose cultivars in terms of the role of the leaf epidermis and xylem vessels in determining differences in water consumption and transport during the stem life in glasses. These results might also contribute to designing post-harvest techniques for optimizing flower quality

Anatomía y micromorfología de hojas y tallos de dos cultivares de rosa hybrida l. para flor de corte

199-204Micromorphological and anatomical differences in leaf epidermis and stem xylem of Rosa hybrida `Lovely Red` (LR) and `Rouge Baiser` (RB), commercially grown in Buenos Aires, Argentina, were examined in the lower half of the terminal leaflet of 5-foliate leaves and in the basal part of stem, respectively. Digital images obtained from SEM and a phase contrast microscope were used with this purpose. Epicuticular wax, which was present on both sides of the leaves, was more abundant in LR than in RB. Stomata were only present on the abaxial side; they were 111 and 129 per mm2 in LR and RB, respectively; the number of epidermal cells was 1025 and 822 mm2 in LR and RB, respectively. No significant differences were observed between cultivars. Lovely Red and RB showed 267 and 308 vessels/mm2 stem, respectively, with a total area of 0.87 and 0.64 mm2/mm2 stem, respectively, and a vessel area of 0.33 and 0.21 mm2, respectively, with significant differences between cultivars for vessel and total area (p less or equal than 0.05). As a result, LR showed a smaller vessel number, but they were larger and with a greater total surface area. Therefore, this cultivar might be better than RB for water transport, although more prone to wilting under water stress. Our results complement other studies on cut rose cultivars in terms of the role of the leaf epidermis and xylem vessels in determining differences in water consumption and transport during the stem life in glasses. These results might also contribute to designing post-harvest techniques for optimizing flower quality

Chromosome contribution to Andean Polyploid Species of Senecio (Asteraceae), from Argentina

Meiotic chromosome numbers were determined and observations of meiotic behavior were made in six species and two hybrid specimens of Senecio L. (Asteraceae). Two different numbers were found: 2n=4x=40 in S. pogonias Cabr., S. ragonesei Cabr., S. sectilis Griseb. and S. viridis Phil. var. radiatus R. E. Fr. and 2n=8x=80 in S. subulatus D. Don. var. subulatus and in S. uspallatensis Hook. et Arn.; the latter showed the same chromosome number previously reported. The chromosome number of the hybrid individuals was 2n=4x=40, being their putative parents S. ragonesei and S. sectilis. B chromosomes were found in some individuals of S. pogonias, S. sectilis, S. subulatus var. subulatus and S. uspallatensis. Many meiotic irregularities such as bridges, fragments, laggard chromosomes, micronuclei and cellular fusion were observed. The results are analyzed in relation to the persistence and success of these polyploids, and the speciation mechanisms operating within this group are discussed.Facultad de Ciencias Naturales y Muse

Achene slime content in some taxa of Matricaria L. (Asteraceae)

The achenes of Matricaria aurea and two varieties of M. chamomilla (var. chamomilla and var. recutita) have slime cells on the surface and they are characterized by slime envelope formation during hydration. The slime in these taxa is composed of pectins and cellulose. The slime could play important role in the distribution and colonisation of new habitats in Matricaria taxa

Estàndares morfologicos de plantas de uso medicinal.

Indagini a livello macro- e micromorfologico di 10 specie di uso medicinale per la formulazione di schede utili alla loro caratterizzazione ed identificazione

Characterizacion macro- y micromorfologica de plantas de uso medicinal.

In order to compile a morphoanatomic atlas based on a series of macro- and microscopical views of medicinal plants as a reference collection, we present a photografic collection of morphological standards from ten species, their organs and their selected parts as their biodiversity documentation and utilization