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  Adelonema
From: "Marek Argent" <abri1973 at wp.pl> on 2011.11.18 at 10:26:22(22315)
Hello,

Is Adelonema a valid genus? I've read about it in the "berlist" published in the IAS homepage.

What species of Homalomena have been moved?

Can I find any document on the web?

Best,

Marek

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From: "Tom Croat" <Thomas.Croat at mobot.org> on 2011.11.18 at 12:47:28(22323)
Dear Marek:

Adelonema is the new name for American
Homalomena. They have been found to be distinct at the molecular level and Adelonema
was an existing name. However, we still need to transfer most of the species
which were described as Homalomena not as Adelonema. We plan to do that after
Pete has the documenting evidence published. The Asian Homalomena are will either
remain in Homalomena or in some cases be moved into still other genera.

Tom

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From: Christopher Rogers <branchiopod at gmail.com> on 2011.11.18 at 14:33:43(22325)
Hiyer Tom,

Do you have a citation for that change, or has it been published yet?

Christopher

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From: "Marek Argent" <abri1973 at wp.pl> on 2011.11.18 at 16:16:09(22330)
Deat Tom,

So does it mean that all American species of Homalomena are now in Adelonema?

Marek

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From: "Tom Croat" <Thomas.Croat at mobot.org> on 2011.11.19 at 20:50:05(22338)
Marek: That will be true. Actually none
are yet transferred. That will require a formal publication where the transfers
are published.

Tom

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From: "Tom Croat" <Thomas.Croat at mobot.org> on 2011.11.19 at 20:57:27(22340)
Dear Christopher. There is no publication
and the main reason that we put it on the IAS website is that I want to cite
the list. Now I can just cite the website.

Tom

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From: Peter Boyce <phymatarum at googlemail.com> on 2011.11.21 at 00:27:17(22352)
Hi Marek, and other aroid-l folks,

Tom as nicely summed up the situation; allow me to put some more meat on the bones.

We have two independent sets of molecular data that show convincingly that the Neotropical species currently assigned to Homalomena do not belong there NOR do they belong in Philodendron – as had been suggested by a previous study [Molecular phylogeny of the genus Philodendron (Araceae): delimitation and infrageneric classification - [Botanical Journal of the Linnean Society 156: 13–27] - Gauthier, Barab & Bruneau 2008].

The ‘coarse’ detail is a molecular clock study by Nauheimer et al, which gives dates the diversification of the Neotropical and Paleotropical clades at a minimum of ca 75 MYA.

The ’fine detail’ comes from a molecular study we’ve done in Malaysia as part of our work on the “true” Homalomena species. This paper is in prep. now, a spin-off from the phylogeny work done by two of our Master’s projects (Ng Kiaw Kiaw – who works on chemical profiling - and Hoe Yin Chen, who’s working on pollination and floral fragrance analyses).

While Curmeria is ‘better known’, the earliest name is Schott’s Adelonema.

The published accepted names () involved for the Neotropics are:

Adelonema

Schott

Prodr. Syst. Aroid.: 316

1860

[T] Adelonema

erythropus

(Mart. ex Schott) Schott

Prodr. Syst. Aroid.: 317

1860

Caladium

erythropus

Mart. ex Engl.

Fl. Bras. 3(2): 172

1878

Curmeria

Linden & Andr

Ill. Hort. 20: 45, t.121

1873

Curmeria

picta

auct.

Gard. Chron., n.s., 1874: 92

1874

[T] Curmeria

picturata

Linden & Andr

Ill. Hort. 20: 45, t.121

1873

Curmeria

roezelii

Mast.

Gard. Chron., n.s., 1874(2): 804

1874

Curmeria

wallisii

(Regel) Mast.

Gard. Chron., n.s., 1877(1): 108

1877

Homalomena

crinipes

Engl.

Bot. Jahrb. Syst. 37: 124

1905

Homalomena

erythropus

(Mart. ex Schott) Engl.

Pflanzenr., 55(IV.23Da): 130

1912

Homalomena

erythropus subsp. allenii

Croat

Aroideana 27: 131

2004

Homalomena

hammelii

Croat & Grayum

Phytologia 82(1): 37

1997

Homalomena

kvistii

Croat

Aroideana 27: 135

2004

Homalomena

moffleriana

Croat & Grayum

Aroideana 27: 137

2004

Homalomena

peltata

Mast.

Gard. Chron., n.s., 1877(?): 273

1877

Homalomena

picturata

(Linden & Andr) Regel

Gartenflora 26: 33

1877

Homalomena

roezelii

(Mast.) Regel

Gartenflora 26: 33

1877

Homalomena

speariae

Bogner & Moffler

Aroideana 7: 37

1984

Homalomena

wallisii

Regel

Gartenflora

1877

Homalomena

wendlandii

Schott

Prodr. Syst. Aroid.: 308

1860

Bold non-italic text are currently accepted species. All of these names above in Homalomena will be combined into Adelonema. Tom has also three new species, and a new variety of H. (A.) crinipes.

Non-bold italics are synonyms

[T] = type species for the genus

Adelonema will comprise 16 taxa.

One additional Neotropical ‘Homalomena’, H. solimoensis G.M.Barroso [Arch. Jard. Bot. Rio de Janeiro 15: 89 1957] was moved to Philodendron by Eduardo as: Philodendron humile E.G.Gon.

Peter

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From: Christopher Rogers <branchiopod at gmail.com> on 2011.11.21 at 07:24:19(22354)
Thanks, Tom!

I look forward to the publication. Any idea where you will publish? I do not want to miss it!

Happy days,

Christopher

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From: brian lee <lbmkjm at yahoo.com> on 2011.11.21 at 09:55:02(22359)
Dear Tom and Peter,

Aloha.

Thank you for all this great work. I find this a very interesting subject. I also look forward to the publlication. Please keep us advised.

Aloha,

Leland

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From: Christopher Rogers <branchiopod at gmail.com> on 2011.11.21 at 09:58:27(22360)
Thank you, Peter and Tom!

So, thinking biogeographically, am I understanding you correctly that Adelonema and Homalomena are sister taxa, having split roughly 75mya? Even 75 mya, these regions were never near each other. Do you think that these genera used to be distributed from South America, across Africa to Southeast Asia? Are there any sister clades in Africa for these genera or for other genus groups with a similar South American/Asian distribution?

Happy days,

Christopher

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From: "Tom Croat" <Thomas.Croat at mobot.org> on 2011.11.21 at 18:08:34(22365)
Dear Christopher: I have a revision
Homalomena that has been worked on for years, really an orphan project that was
started my Mark Moffler with my help. He died suddenly and his advisors took
on the project to finish it but neither of them knew crap about aroid and made
a mash of it. Since then I have not attempted to wrest the project away but
don’t feel like I can commit a lot of time to someone else’s project. I will have to one day. I have totally realigned the species and have
descriptions of most but the introduction needs to be beefed up and there are a
lot of internal inconsistencies in the manuscript at present. Peter and I will
publish a paper to realign the names, transferring them from Homalomena to Adelonema
but he must first publish the paper that verifies these differences.

Tom

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From: "Tom Croat" <Thomas.Croat at mobot.org> on 2011.11.21 at 17:18:17(22366)
Dear Christopher:

I don’t think that there is any
close relative in Africa and it seems rather
unlikely that they got separated by a constipated
bird so I can’t really explain the similarities or the differences. Perhaps
Pete has an idea.

Tom

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From: Peter Boyce <phymatarum at googlemail.com> on 2011.11.22 at 00:59:22(22367)

Dear Christopher, Tom, and folks.

African Culcasieae [Cercestis + Culcasia] is sister to [[[Philodendron][Adelonema]][Homalomena + Furtadoa]]]

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From: Peter Boyce <phymatarum at googlemail.com> on 2011.11.22 at 01:18:28(22368)
There a quite some “shared” clades for this trans ecozone distribution:

The ‘obvious’ ones are the Schismatoglottis Alliance [Philonotion][Cryptocoryneae+Schismatoglottideeae]

The Monsteroideae (with notably Rhaphidophora in W Africa, and IndoMalaya)

The Lasioids, especially Anaphyllopsis (Neotropics) Lasimorpha (W Africa), Anaphyllum (India), Lasia/Cyrtosperma/Podolasia (Asian tropics)

The extraordinary Nephthytis in West Africa & N Borneo

More subtly Aglaonema/Aglaodorum (Asian tropics) is compellingly linked to almost wholly African Nephthytideae.

The most ‘complete’ clade is in American Journal of Botany 98(4), 654–668] - Cusimano et al 2011.pdf

Peter

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From: Christopher Rogers <branchiopod at gmail.com> on 2011.11.22 at 07:42:50(22372)
Wow! Very nice!!!

So, is this data sufficiently robust that a center of radiation can be inferred? Gondwanan maybe?

Happy days,

Christopher

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From: Peter Boyce <phymatarum at googlemail.com> on 2011.11.23 at 01:03:11(22375)
Dear Christopher,

Gondwana is almost certainly the place of origin of the lineage that led to modern aroids. As to age, currently the ‘agreed’-upon molecular clock age is [stem-group] Araceae have been dated to ca 131 million years before present, [crown group] Araceae to ca 128 million years ago (Janssen & Bremer 2004).

Dates for Alismatales [stem-group] are to ca 131 million years before present, [crown group] Alismatales to ca 128 million years before present (Janssen & Bremer 2004; ca 133 and 103 million years before present respectively in Bremer 2000); Magalln & Castillo (2009) suggest ca 147 million years for relaxed and 126 million years for constrained penalized likelihood datings of the beginning of divergence within Alismatales - these dates are probably underestimates [dates presented here are paraphrased from APG http://www.mobot.org/MOBOT/research/APWeb/]

References

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From: "Marek Argent" <abri1973 at wp.pl> on 2011.11.23 at 10:32:19(22385)
...and also Spathiphyllum distributed in the tropical America and Asia/Oceania

Marek

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From: Christopher Rogers <branchiopod at gmail.com> on 2011.11.23 at 09:42:28(22386)
Very nice!!!

Thank you, my friend!

On Wed, Nov 23, 2011 at 3:03 AM, Peter Boyce wrote:

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From: Peter Boyce <phymatarum at googlemail.com> on 2011.11.23 at 22:33:35(22394)
Hi Marek,

That is perhaps the most extraordinary of all; the ONLY explanation can be that species of this genus, once in Africa and probably India, have long-ago gone extinct.

Peter

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From: Lars <larsmaillist at googlemail.com> on 2011.11.24 at 10:45:11(22408)
Hello everybody,

sorry for this mail coming a bit late. I wanted to add something to the
discussion of the aroid biogeography but had problems posting here on
the list.
Well, if you can read this, it means it finally worked. Thanks Steve for
figuring out the problem!

I am just working on the dating and biogeography of the family for my
phd. Basically, I use molecular data and assign fossil to certain nodes
in order to get minimum ages for all other nodes.
It also means, that I don't even have a glimpse of the deep
understanding in the ecology, morphology, and taxonomy of Tom and Peter
(and others), as I just work since a few years with Araceae and mainly
from a molecular point of view.

Having said that, here are some of my results.
(The ages are minimum ages and therefore might be considerably older.)

The spit between Adelonema and Homalomena is relatively young, at least
25 Ma. Maybe 40 Ma is more realistic, but I don't think it is much
older. Although I would like to explain it by vicariance (maybe in a
very warm period in the Paleocene, when there was subtropical climate in
Antarctica and a land connection to Australia). The direction would be
from South America to SE Asia, as Peter told me Philodendron is basal to
the two genera in his more detailed dataset. It is very unlikely that
they got dispersed over the pacific, but not impossible. There have been
some weird long distance dispersals.
If it would be 50-60 Ma a pathway through Antarctica and Australia could
have been possible.

The same young ages (20-30Ma) are in the disjunctions of the Lasioideae
and Monstera (which is in a South East Asian clade).
The split between Philonotion and the rest of the Schismatoglottideae on
the other hand is quiet some time older, at least 45 Ma. With the error
boundary and considering it as minimum a dispersal in the Paleocene
might have been possible.

The Bornean Nephthytis bintuluensis groups with Aglaonema and Aglaodorum
(both from SE Asia), while the rest of Nephthytis groups with Anchomanes
and Pseudohydrosme from Africa. The split between these two groups was
at ~40 Ma.

Rhaphidophora, Amorphophallus, and Arisaema went somewhen in the Miocene
to Africa.

Peltandra (eastern North America) and Typhonodorum / Arophyteae
(Madagascar) have spilt in the Eocene and have had ancestors in Asia
(good fossil record). So it must have been a relatively continuous
connection, or movement later to Africa at the one side and crossing the
Bering Strait at the other.

The Origin of the Araceae is a bit more difficult. The ages are not
really clear, as for the molecular dating with fossil assigned as
minimum ages you have to have a maximum bound at the base.
But they surely go back to the Early Cretaceous (fossil record), maybe
even Jurassic. The true Araceae (without Lemnoids and Proto-Araceae)
most probably come from Gondwana. But reconstructing the real origin it
has to be taken into account the free floating (and mostly world wide
distributed Lemnoids), the today probably only remnant basal
Gymnostachys (Australia) and Orontioideae (Laurasia), and the
Alismatales, the next sistergroup of the Araceae (many in the northern
hemisphere, or marine, or sweet water plants and world wide
distributed). That leaves everything open for speculation and any
reconstruction there is difficult, so to answer an earlier question of
Christopher:
No, there is no data robust enough to give an unambiguous result for the
origin (I guess that is what you mean with center of radiation).

At least that is what the molecules and some modern methods let suggest.

Very best,
Lars

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From: Jason Hernandez <jason.hernandez74 at yahoo.com> on 2011.11.25 at 21:31:16(22413)
This discussion reminds me of something I have been wondering about for a long time. Most books about fossils for laypersons focus on animals; the few on paleobotany tend to give a survey of the evolution of the plant kingdom as a whole. It is very difficult to find anything bringing together the fossil record of a particular plant taxon. If there was a small book -- even with b&w pictures, to save on printing -- on fossil Araceae, I know I would be interested. Who else would be? Do we have sufficient interest to be worthwhile?

Jason Hernandez

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From: Alistair Hay <ajmhay at hotmail.com> on 2011.11.24 at 12:10:08(22414)
I assume Holochlamys (New Guinea) is still in Spathiphylleae?? Tony Rodd (formerly of RBG Sydney) collected Holochlamys sp. in Aceh (N Sumatera). I don't know if it has ever been re-collected there.

From: phymatarum@googlemail.com
To: aroid-l@www.gizmoworks.com

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From: Peter Boyce <phymatarum at googlemail.com> on 2011.11.26 at 05:43:25(22416)
Yes, indeed, still in Spathiphylleae. Never re-collected from Sumatera, but that island still holds many “secrets”, including what appears to be a new genus of Schismatoglottideae.

There is also the ‘odd’ occurrence of Piptospatha on Aru.

From: aroid-l-bounces@www.gizmoworks.com [mailto:aroid-l-bounces@www.gizmoworks.com] On Behalf Of Alistair Hay

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From: brian lee <lbmkjm at yahoo.com> on 2011.11.26 at 08:13:29(22418)
Dear Jason,

Aloha.

I have collected fossils and I would be interested in a book on fossil Araceae. Dr. Ruth Stockey should be contacted. She is a paleobotanist and a member of the IAS.

Thank you for bringing up this subject.

Aloha,

Leland

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From: Corey W <cewickliffe at gmail.com> on 2011.11.26 at 14:12:42(22425)
I know I would be interested in a book of paleobotany, it is an interesting branch on understanding the development of many niches over time. I'm a physical geographer by training and can't help but love texts like that.

One of the most interesting reads I've had in a while was a paper on small freshwater fish species and their radiation on the islands of SE Asia when water levels were lower. Hard for me not to think about aroids like the Cryptocorynes traveling the same way, on rivers that are now just dents on the sea floor...

Corey

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From: Christopher Rogers <branchiopod at gmail.com> on 2011.11.28 at 07:18:12(22432)
Thank you Peter and Lars!

I must echo Jason and Leland's comments on paleobotany. I know far more about the animals than the plants. But I should being a professional zoologist. So, I am far more familiar with the biogeography of my beloved crustaceans. The group I specialize in (Branchiopoda) shows a somewhat similar pattern: one close relationship at both low and high taxonomic levels between the Nearctic and the Palaearctic and a second close relationship between the Afrotropical, Oriental and Australian. The Neotropics are an odd outlier. Only one genus is in common with the Afrotropical, and only two genera and one species is in common with the Nearctic. With my organisms, the Neotropical taxa seem to have mostly evolved in isolation from the other major regions.

How reliable is the molecular data? It seems to me that in the Araceae there must be deep divergence, which would mask some relationships. I guess the Jurassic is maybe not as old as my Cambrian crustaceans, but plants do seem far more flexible both genetically and morphologically.

Happy days,

Christopher

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