Early Floral Resources for Urban Bees From Ornamental Shrubs Ribes Aureum, Ribes Sanguineum and Staphylea Pinnata

This research aims to assess ornamental shrubs Ribes aureum, R. sanguineum and Staphylea pinnata as an early food source for urban bees. In a two-year study, the abundance and flowering pattern, nectar and pollen production, and spectrum of urban insect visitors were investigated in Lublin, SE Poland. The apiarian value of S. pinnata was studied for the first time. The studied species exhibited abundant and extended flowering, skewed inflorescence flowering pattern, and persistent flowers and inflorescences. They bloomed from late March to late May and could be considered as valuable early foraging resources for urban bees, despite the substantial differences between the species. The highest mean sugar yield and pollen yield · plant−1 (92.9 g and 44.0 g, respectively) was estimated for S. pinnata whereas the lowest ones were found in R. sanguineum (4.3 g and 1.8 g, respectively). Hymenopterans were the principal flower visitors in the studied species accounting for more than 79% of all visits.

Hysterographium fraxini. [Descriptions of Fungi and Bacteria].

A description is provided for Hysterographium fraxini. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: recorded on bark of dead branches from a very wide host range. Reports include Acer glabrum (Aceraceae), Cotinus sp. and Rhus typhina (Anacardiaceae), Nerium oleander (Apocynaceae), Alnus viridis, Betula sp. and Corylus sp. (Betulaceae), Bignonia sp. and Catalpa sp. (Bignoniaceae), Diervilla intermedia, Lonicera alpigena, L. tatarica and Viburnum lantana (Caprifoliaceae), Combretum zeyheri (Combretaceae), Cornus mas (Cornaceae), Thuja occidentalis (Cupressaceae), Hippophae rhamnoides (Eleagnaceae), Fagus sylvatica, Nothofagus sp. and Quercus robur (Fagaceae), Phyllostachys nigra (Gramineae), Ribes sanguineum (Grossulariaceae), Hamamelis virginiana (Hamamelidaceae), Juglans sp. (Juglandaceae), Laurus nobilis (Lauraceae), Acacia sp., Caragana arborescens, Gleditsia triacanthos and Laburnum anagyroides (Leguminosae), Liriodendron tulipifera (Magnoliaceae), Morus alba (Moraceae), Fraxinus excelsior, F. latifolia, F. nigra, F. ornus, F. pennsylvanica and F. velutina, Jasminum sp., Ligustrum vulgare, Olea africana, O. cuspidata, O. europaea, Osmanthus aquifolium, Phillyraea sp. and Syringa vulgaris (Oleaceae), Abies cephalonica, Larix decidua, Picea excelsa and Tsuga heterophylla (Pinaceae), Cercocarpus ledifolius, Cotoneaster horizontalis, Crataegus coccineus, Malus pumila, Prunus fruticosa, Pyrus communis and Spiraea japonica (Rosaceae), Zanthoxylum americana (Rutaceae), Populus sp. and Salix sp. (Salicaceae), Celtis australis and Ulmus campestris (Ulmaceae), and Vitis vinifera (Vitaceae). DISEASE: not researched in any detail, but it seems to be saprobic. Early reports of pathogenesis appear to be erroneous. GEOGRAPHICAL DISTRIBUTION: Very widely distributed in temperate regions, with scattered records from the tropics. Reports from Algeria, Argentina, Austria, Canada, Czech Republic, Denmark, Greece, Hungary, Pakistan, Romania, South Africa, Sweden, Switzerland, Turkey, UK, Ukraine, USA (Arizona, California, Colorado, Idaho, Maine, Michigan, North Dakota, Oregon, South Dakota and Washington), and Zimbabwe. TRANSMISSION: not studied, but the ascospores must be air-dispersed and the conidia are probably transmitted primarily through water-splash.

Ornamental Landscape Potential of Several Ribes Species

Several species of Ribes have ornamental qualities worthy of consideration in residential and commercial temperate zone landscape plantings. Ribes sanguineum Pursh has been selected and cultivated throughout the Pacific Northwest, and boasts of early spring flowers of white, pink, or red. The two species of golden currants, R. aureum Pursh and R. odoratum Wendl. f., have brilliant yellow-fl owered racemes. Ribes species exhibit a broad diversity of plant habit and texture ranging from the upright 2.5 m, vigorous, and fully armed Menzieís Gooseberry, R. menziesii Pursh, to the prostrate shade-loving Crater Lake currant, R. erythrocarpum Coville & Leiberg. R. viburnifolium A. Gray remains evergreen in mild climates throughout the year. The foliage of some selections of R. americanum Miller and R. cynosbati L. brighten to a brilliant crimson red in the fall. The fall foliage of other species, such as R. hirsuta L., develop a continuum of color on their branches, from bright red at the apex, through orange and yellow to green towards the base. Spring bloom data and ratings of fall color for species in the Corvallis Repository collection will be described.