With hibiscus, the female portion is on the end of the stamen column. The pollen sacs are yellow and along the column. To hybridize hibiscus without removing the bloom, use a q-tip to place pollen on the stigma pads. Or just remove a bloom and rub the pollen on another blooms pads.
Hope this helps.
[quote="keithp2012"]I tried hybridizing roses and the stamen were easy to clip off leaving just the pistol, how do you remove the stamen on ROS and where are they located so I can hybridize?[/quote]
The one sure way to prevent accidental pollination is to emasculation of Hibiscus flower but this is not without risks. I have one research paper, which I can send you, on hybridizing North American native species which discusses these issues. Several North American species are stealth self-pollinations it you let them. There are a few simple things you can do which reduce the chances of accidental pollination.
1. Hand pollinate early, as the flower is opening.
2. Use pollen overload.
3. Remove the petals of the flower to make the flower less attractive to insects.
There are some other ideas which have been suggested to me but I can’t verify that they work just. I am collecting more information now and will post it if I can verify its accuracy. I really need to solve the problem of pollen storage.
The following paper may provide guidance when cross-pollinating Hibiscus syriacus.
Genetic Affinities of the North American Species of Hibiscus Sect. Trionum
by Dwayne A. Wise and Margaret Y. Menzel
Brittonia, Vol. 23, No. 4 (Oct. - Dec., 1971), pp. 425-437
Stable URL: http://www.jstor.org/stable/2805708
“Cross-pollinations were made involving plants of 34 different accessions. Flowers to be used for pollen were allowed to open inside a building to guard against contamination by foreign pollen. On the afternoon preceding anthesis, petals and anthers were removed from flowers to be pollinated the following morning. Bees seldom visited emasculated flowers, and seldom contaminated the stigmas of those they did visit. The risk of breaking the long slender styles by covering them outweighed the danger of uncontrolled pollination; hence emasculated flowers were not protected.” …
“It should be pointed out that success in crossings between Groups I and II was lower when species of Group I were used as the female parent. Also, crosses within and among accessions of the same species were much more successful for Group II than for Group I plants. Seed set, however, was about the same in both cases. This may indicate only that flowers of Group I were more susceptible to emasculation damage than those of Group II.”
Note: Hibiscus. lasiocarpos, Hibiscus incanus, Hibiscus moscheutos, Hibiscus palustris are identified as Group I; Hibiscus militaris and Hibiscus coccineus are identified as Group II. Hibiscus grandiflorus was considered to be more closely related to Group I. but its reproductive structure most closely resembles Hibiscus syriacus.
What these researches did was cut open flower buds which were about to bloom and remove the petals and anthers, which are along the sides of the style. At this stage the pollen is not yet active, which greatly reduces the chances of accidental pollination and the anthers are safer to handle. The trick of getting flowers, which will be the pollen parent, to bloom indoors is interesting because last year I had cut Hibiscus syriacus stems blooming for weeks indoors, after which time they had roots.
Unlike many Hibiscus, including Hibiscus syriacus, the stigmas of Hibiscus militaris and Hibiscus coccineus are not passive but have the ability to move over the span of several hours. In the early morning the five stigmas are upright encouraging external pollination. By the afternoon the five stigmas bend downward to make contact with the anthers to insure self-pollination as a last resort. This suggests that in their native range, pollinators may be in sufficiently short supply, to make this a useful survival strategy. When working with a Hibiscus which has the reproductive “feature” you have to be very careful if the Hibiscus is to be the pod parent. You can see the same behavior in Hibiscus Lord Baltimore, which has a Hibiscus militaris and Hibiscus coccineus ancestry but the anthers are firing duds in this case.
I have one Internet correspondent who is hybridizing Hibiscus syriacus using cut plastic straws for prevent accidental pollination. What he is doing is cutting a large diameter straw into sections, sufficient in length to cover the style and stigmas, and then slitting the sections lengthwise. The Hibiscus syriacus flowers are hand pollinated and then the straw is snapped over the stigmas and style. While the stigmas at the tip of the style are not completely covered they are not easily accessible either. I have only tested this technique in a very limited number of cases and have not as yet formed an opinion as to its effectiveness. In the paper which I previously referenced, they warned about the dangers of damaging the style.
[quote="keithp2012"]Do I Pinch the anthers off? The style is very delicate so wondering how to safely remove anthers without breaking it.[/quote]
That is a very good question. All of the Hibiscus species discussed in the research paper have reproductive structures which are 4 to 5 times larger than Hibiscus syriacus. During the summer of 2011, using just my fingers the anthers were successfully removed, once the pedals had been cut away because the anthers of Hibiscus moscheutos and Hibiscus grandiflorus, are large and dispersed along the style. In the case of Hibiscus syriacus, in addition to the much smaller size, the anthers are more tightly packed about the style.
The way I remove the pedals is as follows. A bud is locate which is about to open and using a small and sharp pair of scissors, the tip of the bud is removed while avoiding damage to the growing stigmas beneath. Using the small hole at the tip of the bud as a guide, four cuts are made down the length of the bud with the scissors. Peel the four flaps of the pedal fragments back and cutaway the flaps at the base, avoiding damage to the sepals which will protect the growing seedpod, assuming fertilization is successful. Now we have to remove the anthers of Hibiscus syriacus.
This summer I tried using tweezers found in personal grooming kits but was not very successful because I kept dropping the anthers. I just search Amazon and found this low cost set of tweezers for hobbyists at $4.39 plus $3.18 shipping.