1,721,014 research outputs found
Il Biancospino. Alcune osservazioni botaniche a carattere storico, sistematico e farmaceutico sui biancospini (Crataegus laevigata (Poir.) DC. e Crataegus monogyna Jacq.)
No full textMicrospectrophotometric study on the male fern, Dryopteris filix-mas (L.) Schott.. Preliminary results
No full textAlcune osservazioni botaniche a carattere storico, sistematico e farmaceutico su aglio (Allium sativum L.) e menta piperita (Mentha x piperita L.) utilizzati come aromatizzanti nella dieta mediterranea
No full textAlcune osservazioni botaniche a carattere storico, sistematico e farmaceutico sul partenio, Tanacetum parthenium (L.) Sch. Bip. - Asteraceae, attualmente utilizzato nel trattamento della cefalea
No full textLa rappresentazione scientifica di una pianta esotica (Momordica balsamina) in un’opera di autore ignoto (1500 circa) dei Musei Civici di Pavia
Full text linkLocalization of the active principles of the male fern (Dryopteris filix-mas (L.) Schott.) by fluorescence microscopy
No full textThe active principles of the male fern, Dryopteris filix-mas (L.) Schott., consisting of a mixture of phloroglucinol derivatives called “crude filicin”, are localized by means of fluorescence microscopy under U.V. 365 nm and monochromatic blue 435-490 nm lights. Crude filicin is autofluorescent, and therefore may be easily localized in the internal glandular hairs of the intercellular spaces of rhizome and leaf bases parenchyma, without pre-treatment of sections. Localization is confirmed both morphologically and chemically, and is possible on a fresh material, as well as on a desiccated one. The test allows also a complete anatomical examination of sections, and may be useful, for its easiness and quickness, in further taxonomic or pharmacognostic studies. © 1988, The Italian Pharmacological Society. All rights reserved
Some cytological, ecological and evolutionary aspects of pollination
No full textDifferent types of pollen dispersing units are described. The pollen of angiosperms may be dispersed in monads, tetrads, polyads, massulae or compact pollinia. The monads and tetrads may form larger clumps of pollen with the aid of the following substances: a) pollenkitt, a product of in situ degeneration of the tapetum; b) tryphine, a product of tapetal extra situm degeneration, found only in Cruciferae; c) elastoviscin, a highly viscous product of the degeneration of a limited number of tapetal cells, found only in certain Orchidaceae; d) viscin threads or sporopollenin filaments arising from the pollen exine. The number of pollen grains composing the clumps depends on pollen diameter and the cohesive forces holding the pollen grains together. The various types of pollen dispersing unit are discussed in relation to the type of pollination and number of ovules per ovary
Wall projections in the vegetative cell of Parietaria officinalis L. pollen
No full textUltrastructural aspects of pore development in Parietaria officinalis L. pollen are described. The main feature is the presence of intine wall projections formed in correspondence to the pores during the late microspore stage and persisting in the shedding pollen. This structure coexists with the tubules occurring in the pore and first appearing as evaginations of the plasma membrane. The morphological evidence and other features such as the occurrence of mitochondria next or in contact with wall projections lead us to compare the pollen vegetative cell to a transfer-cell. The possible functions of these transfer-cell type structures are discussed. © 1980 Springer-Verlag
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