As suggested by @tyersome in my previous question on the same topic which I posted yesterday, I have cut open few flowers of Allamanda blanchetti in order to observe if any reproductive structures could be found. I took 2 buds in different stages of opening as well,if they had some kind of bud pollination. But it seems there is no difference in the bud and bloomed flower. then I found these yellow long stiff hairs all stuck together, with some transparent secretion on them,no pollen. I think that these hairs cluster together to form this small star shape projection inside the flower we usually see when it is in bloom. and this small green bulb like thing with a thread like extension to attach it to the base of the pedicel. and then on further extending the incision this small swollen part almost like a ovary. But on its transverse section I didn't observe any ovules or placenta inside. I don't have microscope or other high resolution equipment, I tried looking at it with a magnifying glass but no new details appeared. So what are these structures? Do they enable sexual reproduction for the plant? Links to related reliable websites are also welcome.
1$\begingroup$ +1 for the dissection and photos. Good work! $\endgroup$– AdhishOct 1, 2020 at 8:30
$\begingroup$ This is great — I'm glad you got a good answer. If you have lots of flowers, you might want to try dissecting them at different times (e.g. over a number of days after the flower first opens to see how the fruit develops). You can also try some experiments to see whether these flowers are self-pollinating (e.g. enclose a flower in a bag before it opens) and see whether it makes a fruit. 😊 $\endgroup$– tyersomeOct 4, 2020 at 18:32
The third photo gets to the heart of the matter. Here's an enlargement:
The gold-colored areas are the anthers of some of the stamens, the filaments of which are fused with the tissue of the petal. (This is typical of the Apocynaceae, the family to which A. blanchetti belongs; they have epipetalous stamens, that is the stamens are "adnate" i.e. fused with the petal.) This is the male part of the flower; the anthers have the pollen grains which the plant is trying to get transferred to another flower.
Above the knife is the style. This part of the female structure is a hollow tube which runs from the openings in the stigma (the out of focus green blob) down to the ovary (not in photo). The central part of the fourth photo is presumably the ovary (missing its style). The ovary contain the ovules which will become seeds after fertilization from pollen which sticks to the stigma and grows a tube down the style.
$\begingroup$ So the fertilization occurs just like any other flowers[like a hibiscus]? because the anthers and stigma seem hidden . $\endgroup$ Oct 2, 2020 at 6:14
$\begingroup$ Great research articles I couldn't have found them out myself. $\endgroup$ Oct 3, 2020 at 2:36