Annellosympodia orbiculata gen. et sp. nov. and Scolecostigmina flagellariae sp. nov. from Australia

Two new fungi, Annellosympodia orbiculata and Scolecostigmina flagellariae, on Acacia ligulata and Flagellaria indica, respectively, from Australia are described and illustrated. The former species is placed in the new genus Annellosympodia, which is characterised by an unusual combination of features, viz. fasciculate conidiogenous cells (conidiophores reduced to conidiogenous cells), holoblastic conidiogenesis with sympodial, but rectilinear proliferation leaving annular structures and lateral conspicuous conidiogenous loci, and rhexolytic conidial secession. The generic placement of these two fungi is discussed.

Karyological studies on the Sino-Himalayan genus, Cremanthodium (Asteraceae : Senecioneae)

Twenty-two populations of seven species of Cremanthodium from high altitude regions of western China were observed karyologically. C. ellisii, C. microglossum, C. brunneo-pilosum, C. stenoglossum, C. discoideum and C. lineare all had the same chromosome number of 2n=58 whereas C. humile had 2n=60. All chromosome numbers of these species are documented here for the first time. The basic number of x=30 is new for this genus. The karyotypes of all species belong to 2A type according to Stebbins' asymmetry classification of karyotypes. Two basic chromosome numbers, x=30 and x=29 in Cremanthodium, correspond exactly to two branching patterns in this genus, sympodial versus monopodial. The systematic and taxonomic statuses of the sympodial species need further study. The karyomorphological data provide no support to the sectional subdivision in Cremanthodium. (C) 2001 The Linnean Society of London.

Morfoanatomia do sistema caulinar de Canna edulis Kerr-Gawler (Cannaceae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Boron deficiency inhibits petiole and peduncle cell development and reduces growth of cotton

The effect of boron (B) on cotton growth and fruit shedding may be due not only to physiological or biochemical effects, but also to vascular tissue malformation. This experiment investigated petiole and floral peduncle anatomical alterations and growth of cotton supplied with deficient and sufficient B in nutrient solution. Cotton (Gossypium hirsutum cv. 'Delta Opal') plants were grown in solutions containing 0, 1.5, 3.0, 4.5, and 6.0 mu mol L-1 of B from 22 to 36 d after plant emergence (DAPE). From 36 to 51 DAPE, B was omitted from the nutrient solution. Petioles from young leaves and floral bud peduncles (first position of the first sympodial) were sampled and the cross-section anatomy observed under an optical microscope. The number of vascular bundles of the petiole was decreased in B-deficient plants and the xylem was disorganized. Phloem elements in the peduncle vascular cylinder of B-deficient plants did not show clear differentiation. The few xylem elements that were formed were also disorganized. Modifications caused by B deficiency may have impaired B and photosynthate translocation into new cotton growth. Boron accumulation in the shoot of B-deficient plants suggested that there was some B translocation within the plant. It could be inferred that cotton growth would be impaired by the decrease in carbohydrate translocation rather than by B deficiency in the tissue alone.

New light on the systematics of fungi associated with attine ant gardens and the description of escovopsis kreiselii sp nov

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modeling Nymphoides architecture: A morphological analysis of Nymphoides aquatica (Menyanthaceae)

• Premise of the study: Species in the aquatic genus Nymphoides have inflorescences that appear to arise from the petioles of floating leaves. The inflorescence-floating leaf complex can produce vegetative propagules and/or additional inflorescences and leaves. We analyzed the morphology of N. aquatica to determine how this complex relates to whole plant architecture and whether whole plant growth is sympodial or monopodial. • Methods: We used dissections, measurements, and microscopic observations of field-collected plants and plants cultivated for 2 years in outdoor tanks in south Florida, USA. • Key results: Nymphoides aquatica had a submerged plagiotropic rhizome that produced floating leaves in an alternate/spiral phyllotaxy. Rhizomes were composed of successive sympodial units that varied in the number of leaves produced before the apex terminated. The basic sympodial unit had a prophyll that subtended a renewal-shoot bud, a short-petioled leaf (SPL) with floating lamina, and an inflorescence; the SPL axillary bud expanded as a vegetative propagule. Plants produced either successive basic sympodial units or expanded sympodia that intercalated long-petioled leaves between the prophyll and the SPL. • Conclusions: Nymphoides aquatica grows sympodially, forming a rhizome composed of successive basic sympodia and expanded sympodial units. Variations on these types of sympodial growth help explain the branching patterns and leaf morphologies described for other Nymphoides species. Monitoring how these two sympodial phases are affected by water depth provides an ecologically meaningful way to assess N. aquatica’s responses to altered hydrology.

Shoot architecture and growth in the south Florida wet prairie macrophyte, Eleocharis cellulosa

Eleocharis cellulosa is a dominant macrophyte in Everglades wet prairie communities. The development of the shoot system in the genus has been described as sympodial but with an unusual adnation of the horizontal and vertical shoots. The growth pattern of E. cellulosa was studied from field collected plants and plants grown in the greenhouse. Plants were extracted and measurements of horizontal and vertical shoot were taken. Dissections, paraffin sectioning and SEM's were used to examine shoot structure in early developmental stages. E. cellulosa was transplanted from the field to the greenhouse and different levels of Nitrogen and Phosphorus were added to determine how it responded phenotypically. Dissections and microscopy showed that growth of the vertical shoots of E. cellulosa is sympodial, while growth of the horizontal shoots is mixed, beginning monopodially then transforming to sympodial growth. Additions of nutrients did not have any effect on the morphology of E. cellulosa.