Sexual Dimorphism in Catasetum Orchids: Forcible Pollen Emplacement and Male Flower Competition

@article{Romero1986SexualDI,
  title={Sexual Dimorphism in Catasetum Orchids: Forcible Pollen Emplacement and Male Flower Competition},
  author={Gustavo As Romero and Charles Edward Nelson},
  journal={Science},
  year={1986},
  volume={232},
  pages={1538 - 1540}
}
Orchids of the Neotropical genus Catasetum have sexually dimorphic flowers; that is, male and female flowers are distinctly different in shape and color. Male flowers forcibly attach a large pollinarium onto euglossine bees. Euglossa bees leave the male flower in response to pollinarium emplacement by Catasetum ochraceum and subsequently avoid male but not female flowers. This evidence suggests that sexual dimorphism promotes pollination. The aversion of the bee to pollinarium attachment and… 

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References

SHOWING 1-10 OF 15 REFERENCES

POLLINATION AND VARIATION IN THE SUBTRIBE CATASETINAE (ORCHIDACEAE)

TLDR
The pollen throwing apparatus and the pollination mechanisms of the various genera are discussed on the basis of field observations and the production of separate male and female inflorescences is explained as being triggered by the relative amounts of sunlight received by the plants.

Preliminary Studies in the Genus Stanhopea (Orchidaceae)

This preliminary study is an attempt to bring together the knowledge of Taxonomy, Morphology, Phylogeny and Pollination of the species preparatory to a formal revision of the genus. New information,

Food related adaptations in stream living caddisfly larvae feeding on leaves

TLDR
From the nine most common caddisfly shredders in a South Swedish stream five were most abundant in the uppermost section, and food was more effectively used for growth here than further downstream.

Univcrsity colleagues were especially helpful. R. L. DressIer identified the bees. P. L. Romero provided invaluablc assistance in the field

    m m Costa Rica; Romero (5) for C. oebraceum

      ITc hieh polien-donation success suggested for Catastum in

      • 1981

      Forcible emplacement and attachment of pollinarium is characteristic of Catasetum, except for the C. dor alliance (1)