Are infrastipular prickles really modified stipules

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Are infrastipular prickles really modified stipules

Postby Karl K » Tue Dec 20, 2016 11:51 am

While looking into shoot tip abortion, I came across a fascinating book, 'On Buds and Stipules' by Sir John Lubbock.
https://archive.org/stream/onbudsstipul ... 1/mode/2up

On page 188 the author discussed Rosa persica:
"The stem is prickly, and the frequent occurrence of the prickles, sometimes in pairs, at the base of the leaf has led to their description as stipules; for instance, by Boissier in his great ‘Flora Orientalis’."

Lubbock did not offer his opinion on the accuracy of this observation. But it did get me to thinking about infrastipular prickles in general. Lubbock gave examples of prickles that are undoubtedly stipules, such as those of Robinia pseudoacacia.
http://www.rnr.lsu.edu/plantid/species/ ... 3a_web.jpg

Now, compare those to the infrastipular stipules of Rosa woodsii.
https://www.minnesotawildflowers.info/u ... i-15-2.jpg

The relationship of stipules to leaflets is sometimes revealed in hybrids. For example, the orange has simple leaves. The trifoliate orange (Poncirus trifoliata) appears to have three leaflets, but technically the side-leaflets are stipules. But a hybrid of trifoliata and the Thompson Navel orange shows many 5 foliate leaves.
http://bulbnrose.x10.mx/Heredity/Swingl ... 911_07.jpg

I am interested in the occurrence of infrastipular prickles in rose hybrids, and whether these are correlated (linked) with other traits of the parent that provided them.
Karl K
 
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Re: Are infrastipular prickles really modified stipules

Postby Don » Sat Dec 24, 2016 2:33 pm

It is an interesting question and your suggested approach using hybridity seems like a really good one but wonder if ploidy differentials might interfere. My thought experiment would use moyesii, which has huge and long stipules attached along the leaf stem but, being heavily polyploid, might it not yield both stipules and prickles?

Actually, I wonder if I have already done the experiment. I will need to have a look in the spring.
What doesn't kill them makes them stronger.
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Re: Are infrastipular prickles really modified stipules

Postby Karl K » Sat Dec 24, 2016 7:49 pm

Infrastipular stipules seem to be a long-established character of Rosa, whether habitual or occasional. Getting these to revert to a more "traditional" sort of stipule might require intergeneric hybridization - like the hybrid of Poncirus and Citrus seemingly reverting to an ancestral form with pinnate leaves.

And on that possibility, I recently found a very suggestive paper by O. F. Cook, 'Jointed leaves of Amygdalaceae.' (1912).
http://bulbnrose.x10.mx/Heredity/CookLeaves1912.html

Amygdalaceae is the old name for Prunus. Cook pointed out that the joint at the base of the leaf, and nectaries on the leaves of some apricots, are evidence that these species are descended from ancestors with compound leaves.
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Re: Are infrastipular prickles really modified stipules

Postby Karl K » Mon Feb 13, 2017 11:10 am

The Gardeners' Monthly and Horticulturist, 29: 376-377 (Dec 1887)
On The Stipules Of Magnolia Frazeri.
Thomas Meehan
"In many species of roses, especially in Rosa Kamtschatica and Rosa cinnamomea, the stipules could be noted increasing, and the size of the leaf blade diminishing on the branch as it approached infloresence. Often the tips of the sepals would develop to minute leaf blades; and in a few instances he had seen the same appendages on abnormal petals. Often the stipules, especially in Rosa Kamtschatica, would have the red colors of the petals, when at the nodes, immediately below the axis from which the peduncle proceeded. There could be no possible doubt in the minds of those who would carefully compare, and watch for occasional aberrations, that the petals of the rose were rather transformed petals [sic: I think this should be "transformed stipules"] than complete leaves."
http://bulbnrose.x10.mx/Heredity/Meehan ... s1887.html
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Re: Are infrastipular prickles really modified stipules

Postby Don » Mon Feb 13, 2017 6:19 pm

>> the petals of the rose were rather transformed..transformed stipules..than complete leaves.

Hmmm. I would think that this question has already been answered by the folks who study inflorescence. Does anybody here from academia know if petals and stipules are the same bird?
What doesn't kill them makes them stronger.
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Re: Are infrastipular prickles really modified stipules

Postby Karl K » Tue Feb 14, 2017 9:27 am

Don wrote:>> the petals of the rose were rather transformed..transformed stipules..than complete leaves.

Hmmm. I would think that this question has already been answered by the folks who study inflorescence. Does anybody here from academia know if petals and stipules are the same bird?

I would be interested to learn of any research subsequent to Meehan's.

BTW, the Bot. Reg. illustration of Rosa ferox shows the red pigment in the stipules immediately below the flower. At this point in my research, R. ferox and R. kamchatica seem to be selections of the same, small-leafed species.
http://bulbnrose.x10.mx/Roses/Rose_Pict ... ferox.html

Karl
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Re: Are infrastipular prickles really modified stipules

Postby Karl K » Wed Feb 15, 2017 9:37 am

A further report from Meehan on stipules and petals:

Proceedings of the Academy of Natural Sciences of Philadelphia 41: 53-66 (1889)
Contributions to the Life Histories of Plants. No. IV
Thomas Meehan
Clear as it is to the mind that when carefully traced, the petal of a rose is formed of an enlarged stipule, and not of a fully planned leaf, the positive evidence is not furnished as freely as in the case of the sepal, but specimens of Rosa humilis, sent to me in 1883 by Miss Jennie E. Whiteside, of Harmonsburg, Pennsylvania, give an excellent illustration. This form has been figured and described by Mr. Sereno Watson in the Garden and Forest for February 13th, 1889 as Rosa humilis, var triloba. The trilobed petal is simply a case in which the usual stipule forming the petal of the rose, has again had its normal growth accelerated towards a perfect leaf. The central lobe is in fact no more than a dilated petiole, with the stipule represented by the two lateral lobes, in its normal position at its base. The same process from the total arrestation of petiole and leaf blade to the abnormal dilation of the stipule to form the petal, can be traced in magnolia, as made plain in the paper above cited.
https://books.google.com/books?id=dHkOA ... &q&f=false


Image
Rosa humilis var triloba
http://bulbnrose.x10.mx/Roses/Rose_Pict ... iloba.html
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