flava atropurpurea or rubricorpora


gardenofeden
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Was Schnell correct to separate the species into varieties? There are so many gradations between the varieties that it is often impossible to assign a particular plant to one or other. He identified six varieties but could as easily have described sixteen...

Looking at the photo my reaction would be var. atropurpurea (I don't have Schnell's book to hand to check the description), but others may see it differently. Growing conditions also play a large role. The plant would look very different if it was grown in lower light levels.

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Schnell:

"var. atropurpurea: lid and external pitcher tube deep red in ideal growing conditions; pitcher interior pale tan or also red. When cultivated, the deep red colour is often difficult to maintain and even plants brought in will fade perceptibly in a few weeks.

"Var. rubricorpora: the external tube is entirely deep red to reddish purple in full sun, the tube lining is yellowish buff, but the lid is green with prominent red veins"

... so, my interpretation is that if it has a red tube and a red lid, or mostly red lid or anything except for "green with prominent red veins" then it is atropurpurea.

As Aidan has pointed out, there are so many gradations. For example, my "giant red tube" does not have a yellowish buff tube lining, but it is definite rubricorpora in my eyes... perhaps Schnell was being too simplistic?

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...perhaps Schnell was being too simplistic?

Schnell took on an impossible task. S. flava displays an entire spectrum of colour from (largely) all-green through all-red. To separate the species into varieties, at some point a decision had to be made as to what defined a particular variety. Obviously his decisions were based on informed opinion, but to some degree the selection of the point along the spectrum where a particular variety is defined as lying must be arbitrary. As Stephen has demonstrated this leads to acute problems in identifying plants, particularly at the red end of the scale.

The defining of varieties should have clarified the situation. Unfortunately, it appears to have done the opposite.

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A rubricorpora x atropurpurea cross might produce say, some all red plants apart from underneath the hood for example. Without knowing the parentage, it would be very hard to put it in either category!

What would you class this plant as?

http://i6.ebayimg.com/01/i/06/3c/3e/d2_1_b.JPG

Too faintly veined for ornata according to Schnell and lacking in the features described for var. flava :?

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It's hard to tell what that picture is other than to say it is flava of some sort. It looks as though the picture has been taken in the dark and the unnatural light is masking its true colours.

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Phil - There is an interesting paper on anthocyanins here:

http://www.charlies-web.com/specialtopics/anthocyanin.html

A short quote relevant to your question:

Environmental factors affecting anthocyanin production included light (intensity and wavelength, with blue and UV being most effective), temperature, water and carbohydrate levels, and the concentrations of the elements nitrogen, phosphorous and boron in the growth medium. Anthocyanin production can be induced by light, blue being the most effective color. Low light levels also induce the formation of different flavonoid pigments, which is another interesting adaptive response on the part of plants. (Tillandsias, for example, develop a bright red coloration due to induced anthocyanin production if grown in strong light.
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Rob, can you explain further - "Strongly acidic soils are conducive to heavy anthocyanin production. Tannin?"

Im just looking at light/pigment relations at college.

What Aiden said :-D

Reagrding tannin reminds me of tea... I have experimented on a spare "dark" S. purpurea the last year actually. One division went into a weakly acid bog garden, the other into a peat mix and applied a weak infusion of common-or-garden stewed tea every so often. The latter is much redder, verging on purple-black. I don't advocate pouring tea over all CPs, but I have also used it effectively for the short-term control of algae in an indoor culture of U. gibba. I forget if the forum thread about that was on the old forum a number of years back, or whether you might find it here with the search thing...

Bear in mind that tannin (in tea) is not tannic acid though.

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  • 2 weeks later...

The only trouble with varietal names is, when a rubricorpora does turn all red ( I have one that goes all red in summer, standard textbook description of rubricorpora in spring), you have a hard time convincing anyone it isn't an atropurpurea. However, by varietal names, it just changed its own identity! Sometimes these guys are sinister!

One other thing, I have to use tannic tea (Rob Sacilotos recipe) in order for my atropurpurea's to turn red. Otherwise they look very ornata like with a rugelii style throat blotch. Which IS attractive BTW!

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