Homalomena/Dieffenbachia.

From: "Julius Boos" ju-bo at msn.com> on 2002.07.20 at 20:38:06(9121) Dear Jonathon, I have seen this plant for sale at a nursery here in WPB, Florida, it is certainly a species of Homalomena, NOT a hybrid between two VERY different genera/tribes of aroids! It is a very pretty plant, but seems sensative to sun burn and fungus/viral problems. I believe it is produced by tissue culture. To my knowledge there has been one intergeneric cross in the Araceae, that of Colocasia with Alocasia, and these are VERY closely related genera, so close in fact that there is talk of 'sinking' one into the other. I have also heard through the 'grape vine' that there was a claim made on an Asian 'talk group' that someone had crossed a Xanthosoma with a Caladium , but because of the ongoing confusion if identifying plants of these two genera decisivly (there is a Xanthosoma aristeguietae illustrated as a Caladium on pg. 208 of TGOA) this claim is probably based on a misidentification of a plant as belonging to another genus. Caladiums have their pollen shed in monads (single globular grains) , while Xanthosoma sheds its pollen in tetrads (groups of four grains stuck together), so I am informed that cross-breeding between these two genera is highly unlikely. We must bear in mind that research on aroids is an ongoing discipline, as yet nothing (or few things!) are cast in stone! Hope that this helps. Julius +More >>Your phrasing about possible snippets for inclusion made me remember a question that I had for this group, whether appropriate for the newsletter or not. While on vacation recently, a came across a plant at a nursery which was labelled Dieffenbachia - however, the growth habit was much more clearly Homalomena, although the leaves were much larger than any Homalomena I have seen, with leaf blades averaging between 10 - 12 " long and 6 1/2" wide, good-sized leaves for a Dieffenbachia even, and very nicely patterned as well, with three different shades of green, darkest to the outside, and a pinkish cast to the underside surface. But the plant was less than 6" tall, with numerous leaves lying flat on the ground and several growing points obvious. I suggested to the greenhouse person who was watering, and apparently also in charge, that the label might be incorrect, and she told me that she had been told that it was a cross between Homalomena and Dieffenbachia when she raised the same question as me to the grower. Have there in fact been any cross genus hybrids made with these two genera, or was the grower just trying to not appear to be less knowledgable than the person to whom he was selling these plants? Any opinions? Jonathan<< Jonathan Ertelt, Greenhouse Manager Department of Biological Sciences Vanderbilt University Box 351634, Sta. B Nashville, TN 37235 (615) 322-4054 jonathan.ertelt@vanderbilt.edu ** NOTE NEW UNIVERSITY MAILING ADDRESS, AS OF 7/15/02 ** (home address remains the same)

From: "Eduardo Goncalves" edggon at hotmail.com> on 2002.07.21 at 03:44:21(9122) Dear Aroiders, Just a note. Some years (1984) ago Josef Bogner & Mark Moffler described Homalomena speariae (Aroideana 7(2): 37. 1984.), a huge "Dieffenbachia-like" Homalomena. Another "common" Homalomena, H. wallisii, that is also Dieffenbachia-like, but a little smaller. Homalomena wallisii is quite widespread in cultivation, and H. speariae was in cultivation in the past. Maybe someone saw one of these plants and said it was an hybrid, so the legend begins. Dieffenbachia has an unusuall chromosome number (34 or polyploid series of it) and it must be somewhat hard to cross with other aroid genera (except the other Spathicarpoids that are closer relatives). My advice is: check those both species before believe that there is an intergeneric hybrid. They really LOOK like Dieffenbachia, but they are not even so closely related (Homalomenas are closer to Philodendron, as far as I know). Dieffenbachia-like species are known in Neotropical Homalomena. The real and interesting question is: Are Neotropical Homalomena and Paleotropical Homalomena really the same genus? (someone from the molecular side of the life to answer this?) Well, I have the same question for Schismatoglottis (I have to confess that in both genera I do not believe they are, but I have no consistent argument)... Well, but this is another discussion... +More Very best wishes, Eduardo. Very best wishes, Eduardo. Reply-To: aroid-l@mobot.org To: Multiple recipients of list AROID-L Subject: Re: Homalomena/Dieffenbachia. Date: Sat, 20 Jul 2002 15:37:54 -0500 (CDT) Dear Jonathon, I have seen this plant for sale at a nursery here in WPB, Florida, it is certainly a species of Homalomena, NOT a hybrid between two VERY different genera/tribes of aroids! It is a very pretty plant, but seems sensative to sun burn and fungus/viral problems. I believe it is produced by tissue culture. To my knowledge there has been one intergeneric cross in the Araceae, that of Colocasia with Alocasia, and these are VERY closely related genera, so close in fact that there is talk of 'sinking' one into the other. I have also heard through the 'grape vine' that there was a claim made on an Asian 'talk group' that someone had crossed a Xanthosoma with a Caladium , but because of the ongoing confusion if identifying plants of these two genera decisivly (there is a Xanthosoma aristeguietae illustrated as a Caladium on pg. 208 of TGOA) this claim is probably based on a misidentification of a plant as belonging to another genus. Caladiums have their pollen shed in monads (single globular grains) , while Xanthosoma sheds its pollen in tetrads (groups of four grains stuck together), so I am informed that cross-breeding between these two genera is highly unlikely. We must bear in mind that research on aroids is an ongoing discipline, as yet nothing (or few things!) are cast in stone! Hope that this helps. Julius >>Your phrasing about possible snippets for inclusion made me remember a question that I had for this group, whether appropriate for the newsletter or not. While on vacation recently, a came across a plant at a nursery which was labelled Dieffenbachia - however, the growth habit was much more clearly Homalomena, although the leaves were much larger than any Homalomena I have seen, with leaf blades averaging between 10 - 12 " long and 6 1/2" wide, good-sized leaves for a Dieffenbachia even, and very nicely patterned as well, with three different shades of green, darkest to the outside, and a pinkish cast to the underside surface. But the plant was less than 6" tall, with numerous leaves lying flat on the ground and several growing points obvious. I suggested to the greenhouse person who was watering, and apparently also in charge, that the label might be incorrect, and she told me that she had been told that it was a cross between Homalomena and Dieffenbachia when she raised the same question as me to the grower. Have there in fact been any cross genus hybrids made with these two genera, or was the grower just trying to not appear to be less knowledgable than the person to whom he was selling these plants? Any opinions? Jonathan<< Jonathan Ertelt, Greenhouse Manager Department of Biological Sciences Vanderbilt University Box 351634, Sta. B Nashville, TN 37235 (615) 322-4054 jonathan.ertelt@vanderbilt.edu ** NOTE NEW UNIVERSITY MAILING ADDRESS, AS OF 7/15/02 ** (home address remains the same) Eduardo G. Goncalves Laboratorio de Fitoquimica Depto. de Botanica - IB Universidade de Sao Paulo Caixa Postal 11461 - CEP 05422-970 Sao Paulo - SP - BRAZIL e-mail: edggon@hotmail.com edggon@ib.usp.br Phone: 55 11 3091-7532 FAX : 55 11 3091-7547 _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com

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