(POLLINATION PROMOTION CONCEPTS IN APOCYNACEAE )
What is found commonly as a trend in this family is the concept of putrid odors used for attracting a pollinator that would not mind traveling distances for the source(Flies) is the most common out of all vectors). Since distance between plants can be relatively far, the smell must be strong enough to be detected. In the case of this plant far travel can be necessary but usually colonies are seen relatively close. The Flowers are produced relatively under the grade and are most commonly pollinated by ants and beetles instead of what is the usual trend of flies.
With that said, the plant above still produces quite the odor and has many methods for getting it’s sent out there. When a plant with a corolla tube forms, sometimes it balloons, building up a pressure gradient that can release volatiles in a more concentrated release causing what can be perceived as a heavier scent. The corolla also has individual separations in scent producing glands that act as guide for insects by osmophore regulation. (I plan on discussing this concept in more detail at a later time). Once attracted to the flower the insect then enters the cage like trap then travels down the corolla tube that has downward facing hair like structures that one may find strigose in habit; these are similar to that of the genera Ceropegia (will also talk about this at a later time.) Also, like Ceropegia flowers, these wither away releasing the insect after a brief stay. One may also expect the elaiophores, which produce oils, coupled with the partially glandular/papillate surface cells for an even more successful polination interaction.
*Stapeliopsis (Pectinaria* may be preferred) saxatilis -an endemic to South Africa.
Photographed by: Robin Frandsen in situ.
For more see: http://www.jstor.org/stable/i40105872 (Cactus and Succulent Journal of Great Britain 43(2–3): 77. 1981)
http://www.gbif.org/species/7311938
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