Yahoo Italia Ricerca nel Web

Risultati di ricerca

  1. Fertilisation of Orchids is a book by English naturalist Charles Darwin published on 15 May 1862 under the full explanatory title On the Various Contrivances by Which British and Foreign Orchids Are Fertilised by Insects, and On the Good Effects of Intercrossing.

    • Charles Darwin
    • 1862
  2. Abstract. MR. DARWIN, in his “Fertilisation of Orchids,” speaks of a Madagascar orchid ( Angræcum sesquipedale) with nectaries 11½ inches long, and supposes that these plants must be ...

    • W. A. Forbes
    • 1873
  3. 1 set 2021 · In this regard, propagation in vitro is one of the most important breeding methods for orchids, as orchid seeds are difficult to reproduce in the natural environment. Seed maturity, culture conditions, and culture media are key factors affecting the efficiency of in vitro propagation.

  4. Orchids was the first of the botanical books which Darwin published from 1862, all of which 'exalted' plants and showed how closely linked to animals they are. Several of these books, such as Cross and self-fertilisation (1876), developed the sexual theme initiated in Orchids.

  5. It was concerned with working out in detail the relationships between sexual structures of orchids and the insects which fertilise them, their evolution being attributed to natural selection. It is therefore the first of the volumes of supporting evidence.

  6. 12 feb 2018 · He suggested that cross-fertilisation – in which one plant is fertilised by pollen from another – would increase a plant’s genetic fitness and provide the diversity needed for natural selection, leading to evolution and the development of new species.

  7. 21 giu 2006 · Here we describe a new type of self-pollination mechanism in the tree-living orchid Holcoglossum amesianum, in which the bisexual flower turns its anther against gravity through 360° in order to...