Xanthosoma (fwd)

From: Don Burns <burns at mobot.org> on 1998.05.14 at 22:51:52(2130) ---------- Forwarded message ---------- Date: Thu, 14 May 1998 17:47:07 -0500 To: aroid-owner@mobot.org +More Subject: Xanthosoma This message was submitted by Eduardo to list aroid-l@mobot.org. If you forward it back to the list, it will be distribut= ed without the paragraphs above the dashed line. You may edit the Subject: lin= e and the text of the message before forwarding it back. If you edit the messages you receive into a digest, you will need to remove these paragraphs and the dashed line before mailing the result to the list. Finally, if you need more information from the author of this message, you should be able to do so by simply replying to this note. ----------------------- Message requiring your approval -------------------= --- Sender: Eduardo Subject: Xanthosoma Dear Bob, Unfortunately, I am not aware about someone working with the whole group. Xanthosoma is one of the ``black holes`` of aroids´ taxonomy, and researchers seem to be avoiding it. I am describing two new species of such genus from Brazil, and would love to revise it in a near future (not so near, because I am currently revising Spathicarpa). I am also aware that Josef Bogner (from Germany) is describing another new Xanthosoma, but nobody (as long as I know) is dealing with the genus as a whole. That is really a pity, because Xanthosoma are real beauties, and they are also important economically (as food crops, ornamental plants, etc). About your question concerning the terminology, basal ribs are the main nerves of the posterior lobes of the leaf. If you are facing a Xanthosoma leaf frontally (at least in those species whose leaves that are cordate or sagittate in outline), you will see a kind of ``Y`` that are the main nerves of the leaves. They are the thickest nerves and are very easy to recognise in the upper surface of the leaf. The two upper ``arms`` of the ``Y`` are the basal ribs. When I say that they are denuded, I am meaning that the leaf blade of the basal lobes are lacking in a small strech of the nerve, near the petiole insertion. When they arent denuded, the insertion of leaf blade in the lobe is exactly on the insertion of the petiole. I know, it is very easy to show, and very hard to explain (mainly to me, because English isnt my native language!), but I think you can imagine. If you couldnt do it based on my description in ``crazy English``, e-mail me privately and I can send you a digitalized drawing of the two kinds of leaves. Best wishes, Eduardo. Bob Riffle wrote: > > Oh, Eduardo, DECIDEDLY there needs to be taxonomic research done on > these things! Do you know of anyone or group who IS working on > them. It's rather hard to believe that it hasn't already happened > because of the extraordinary beauty of these things ....

From: Bob Riffle <71270.3070 at compuserve.com> on 1998.05.15 at 01:33:02(2133) Eduardo, yes, it is a shame the lack of interest and (or so I'm surmising) lack of funds that might get the research done. I know in the popular culture of this country it's probably at the bottom ot the list of "important" considerations, but not at the bottom of mine. Seems to me that's one of the things wrong with popular culture: a near total lack of appreciation of things of beauty in the natural world. Well, I'll cease and desist now and gingerly get down from the soapbox .... I'd love to have the digitized drawing, but it may not be necessary if you answer this question: What are the "the two kinds of leaves" you mention? Would one of them be "peltate?" That terminology I know. And, if I'm on the right track, is what you're trying to tell me that in the one case the petiole meets the main blade of the leaf at the precise point at which the basal lobes diverge from the rest (apex) of the main leaf blade?--and, in the other case, that the petiole joins the main leaf blade beneath the point at which the basal lobes diverge from the rest of the leaf blade? And, to be specific, that the leaf of X. violacea is an example of the former case (or nearly so) and that the leaf of X. sagittifolia is an example of the latter case (or nearly so)? +More Yes, a picture is worth MORE than a thousand words .... Thanks again .... Is thanks also due to Anastasios Kotsikanos? I don't completely understand all the "headers" of these things ....

From: "Dr. Tom Croat" <tcroat at lehmann.mobot.org> on 1998.05.15 at 15:33:23(2138) Aroiders: For those of you who have been discussing Xanthosoma in recent days I can concur that it is a taxonomic mess. I would encourage you to bring into cultivation as many species as possible and demand collection data where possible. This will be instrumental in a proper understanding of the genus. Dr. Sue Thompson is working on Xanthosoma but still has a long way to go to fully know them and I suspect that she has been reluctant to come forward in this discussion to avoid being bombarded with questions that no one can yet answer. I would further encourage you to send her material to cultivate because studying them alive is essential. Sue is on aroid-l. She works at the Carnegie Museum. Tom

From: "Julius Boos" <ju-bo at email.msn.com> on 1998.05.16 at 02:10:08(2145) -----Original Message----- To: ju-bo@msn.com Date: Friday, May 15, 1998 11:24 AM Subject: Re: Xanthosoma (fwd) Dear Aroiders, A further note on the "new" (to me) Xanthosoma sp. that I recently saw at a nursery being grown for a customer, and which I at first thought was X. violacium due to the reddish/ purple color of the tubers/corms-- I was back there today, and took a closer look at the plants produced by these "new" reddish tubers, to me indistinguishable from the tubers of "red co co" at the Jamaican and Cuban stores, which I have previously bought and have grown to be "true" X. violacium, and was told that Winn Dixie, where they were purchased, said that they are imported from Costa Rica. The leaves are all-green with a wax-like coating that gives them a silvery-greyish look. The anterior blade lobe points upward, and the points of the posterior lobes also curve and point upwards. The texture of the blade is smooth and heavy, and the margins are gently curved. The naked areas of the main ribs of the posterior lobes are VERY short, not as long as in "true" X. violacium or X. sagittifolia. NO sign of purple on petiole or blade. The interior of the tuber/corm is white, while "red co co" has some streaks of red/purple in its flesh, even after it is cooked (boiled). I will be interested to ask any Jamicans I come across if they noticed a difference in the edibility, as they MUCH prefer the "red co co" (true X. violacium) to the "white co co" (x. sagittifolia), as they say the red co co "does not scratch" (itch) as does white co co. I will have to photograph these plants, and since I gave the one plant that I grew of the scarce "yellow malanga" to one of my many friends, I will have to get another and grow it, also to be photographed, as my memory of its plant is simular to this "new" one. Have you all noticed that in Deni Bown`s book she calls the Xanthosoma with the "pockets" at the leaf tips, AND the yellow fleshed, edible Xanthosoma, X. atrovirens?? Surely they are not the same? Also, there is a BEAUTIFUL,slender and tall (4 ft.) Xanthosoma sp. locally, its leaves are elongately sagittate, crinkled, with silvery and darker stripes that are along the viens, someone once told me its name, but I can not bring it to mind at the moment. Anyone remember it? Tom, do you have Sue`s address where one can post plants/ tubers to? Cheers, Julius +More ju-bo@msn.com Aroiders: For those of you who have been discussing Xanthosoma in recent days I can concur that it is a taxonomic mess. I would encourage you to bring into cultivation as many species as possible and demand collection data where possible. This will be instrumental in a proper understanding of the genus. Dr. Sue Thompson is working on Xanthosoma but still has a long way to go to fully know them and I suspect that she has been reluctant to come forward in this discussion to avoid being bombarded with questions that no one can yet answer. I would further encourage you to send her material to cultivate because studying them alive is essential. Sue is on aroid-l. She works at the Carnegie Museum. Tom

From: Bob Riffle <71270.3070 at compuserve.com> on 1998.05.16 at 04:31:44(2148) I'm fairly certain it's not what I kept thinking when I read this Also, there is a BEAUTIFUL,slender and tall (4 ft.) Xanthosoma sp. locally, its leaves are elongately sagittate, crinkled, with silvery and darker stripes that are along the viens, someone once told me its name, but I can not bring it to mind at the moment but what I thought was Xanthosoma undipes (X. jacquinii)

From: "Julius Boos" <ju-bo at email.msn.com> on 1998.05.17 at 01:52:25(2150) -----Original Message----- To: ju-bo@msn.com Date: Saturday, May 16, 1998 12:23 AM Subject: Re: Xanthosoma (fwd) Dear Bob, It may be X. jacquinii that I`m trying to recall, but certainly not X. undipes, a plant which is common in the river valleys of Trinidad, W.I.; it is a HUGE plant with a recumbent rhizome/trunk about 6" thick and sometimes many feet long, its leaves are simular to the cultivated X. sagittifolia, but have a shiny , light texture, and the clincher is that the sap which is brownish, STINKS, and it exudes it in large quantities. Anyone else have any ideas on the name of the slender Xanthosoma? Sometime last year there was a picture posted of one of the pubescent-leaved, smaller Xanthosomas in bloom, and we debated for quite a while as to its "true" I.D. ( I believe we setteled on X. mexicanum or somesuch), but I could not find the photo when I looked around this A.M.-- anyone know where it is, as I`m sure that you would enjoy it, Bob. Cheers, Julius +More ju-bo@msn.com I'm fairly certain it's not what I kept thinking when I read this Also, there is a BEAUTIFUL,slender and tall (4 ft.) Xanthosoma sp. locally, its leaves are elongately sagittate, crinkled, with silvery and darker stripes that are along the viens, someone once told me its name, but I can not bring it to mind at the moment but what I thought was Xanthosoma undipes (X. jacquinii)

From: Krzysztof Kozminski <kk at netgate.net> on 1998.05.17 at 01:56:21(2151) Julius Boos wrote: Also, there is a BEAUTIFUL,slender and tall (4 ft.) > Xanthosoma sp. locally, its leaves are elongately sagittate, crinkled, with > silvery and darker stripes that are along the viens, someone once told me > its name, but I can not bring it to mind at the moment. Anyone remember it? Could it be X. lindenii magnificum ? -- +More ====================================== Krzysztof Kozminski http://www.netgate.net/~kk/ kk@netgate.net "Applying computer technology is simply finding the right wrench to pound in the correct screw."

From: Bob Riffle <71270.3070 at compuserve.com> on 1998.05.17 at 03:06:17(2153) Jeez, the Griffiths' INDEX OF GARDEN PLANTS indicates that "Xanthosoma jacquinii" is a synonym for "Xanthosoma undipes" and, if you have EXOTICA or TROPICA, there is a photo of X. jacquinii that seems to fit the description you posted. Maybe neither is correct--probably EXOTICA/TROPICA has the original mistake .... I heard Bill Gates not too long ago say something like "What's a hundred million here or a hundred million there?" For 0.001 of that amount he could fund all the research we need! Are you counting on it?

From: "Julius Boos" <ju-bo at email.msn.com> on 1998.05.17 at 14:26:26(2154) Dear Krzysztof, No, I know X. (caladium) lindenii "magnificum"; I believe the one I`m trying to remember the name of is in fact X. jacquinii. Thanks for trying. Sincerely, Julius +More ju-bo@msn.com >Julius Boos wrote: Also, there is a BEAUTIFUL,slender and tall (4 ft.) > Xanthosoma sp. locally, its leaves are elongately sagittate, crinkled, with > silvery and darker stripes that are along the viens, someone once told me > its name, but I can not bring it to mind at the moment. Anyone remember it? >Could it be X. lindenii magnificum ? -- ====================================== >Krzysztof Kozminski http://www.netgate.net/~kk/ kk@netgate.net "Applying computer technology is simply finding the right wrench to pound in the correct screw."<

From: "Julius Boos" <ju-bo at email.msn.com> on 1998.05.17 at 14:32:42(2155) Dear Bob and Aroider friends, I believe that X. jaquinii is the name that I was looking for-- X. undipes is not a synonym of it IF Simon Mayo is correct, and I believe he is, in his work on the Aroids of Trinidad, where X. undipes (?) is common. All this will be sorted out when the revision is complete, maybe in our lifetimes. A lot of the confusion in some of the Xanthosomas is with the cultivated vars., both the ornamental ones ( eg. X. "atrovirens" in its forms) and the ones grown for food throughout their range. I am going to suggest that we begin posting photos with data of the ones we grow from commercially available sources, and I will begin by photographing the plants of the "new" purplish-tubered Xanthosoma bought at Winn Dixie recently, and said to be from Costa Rica, which is called "malanga lilac" by the Jamaicans where I origanally bought my "red co co" tubers. They knew EXACTLY what I was discribing when I asked them about it yesterday, as they hold their "red co co" dear to their hearts, it is firmer and "drier" when cooked, and does not itch. I +More also want to take a closer look at the tubers, as now that I know that I am dealing with two species/forms, not one, I am seeing differences between the tubers. I have also located the plant grown from the bright yellow-fleshed Xanthosoma, "malanga (or yautia) amarilla " said to be common and popular in the Dominican Republic, and will obtain and post a photo, as I remember its plant as being simular in color to the "new" malanga lilac from Winn Dixie. Lester Kallus, maybe we could incorporate the photos on your web page? For those of us who do not know where it is, the url is-- http://www.i2i-2000.com/~lkallus/aroids/plnthome.htm >Jeez, the Griffiths' INDEX OF GARDEN PLANTS indicates that "Xanthosoma jacquinii" is a synonym for "Xanthosoma undipes" and, if you have EXOTICA or TROPICA, there is a photo of X. jacquinii that seems to fit the description you posted. Maybe neither is correct--probably EXOTICA/TROPICA has the original mistake ....< >I heard Bill Gates not too long ago say something like "What's a hundred million here or a hundred million there?" For 0.001 of that amount he could fund all the research we need! Are you counting on it? << I`ll end this now, and wait for feed back. Cheers to all, Julius ju-bo@msn.com

Note: this is a very old post, so no reply function is available.