Aroids (the family Araceae)

[Lesley Cox]

Those are amazing species Johan. I've never seen anything at all like them. I really like Arisaema fimbriatum. There would be no problem identifying that species when in bloom.

[WimB]

Johan,

love the A. fimbriatum ssp. fimbriatum, very beautiful.
The amorphophallus are very nice too.
I'm sorry but it looks like the leaves of those two Arisaema's are indeed virussed. It's best to get rid of them.

Lesley, there are some other Arisaema's which have a spadix covered with bristles too, they are in the section anomala, like A. victoriae, A. lihenganum and A. ornatum.

[TheOnionMan]

Arisaema, another of my favorite genera... never saw anything like Arisaema fimbriatum, amazing. 

I just dug out an old digital image of Arisaema taiwanense which was displayed at a local NARGS chapter plant show in 2002, grown under greenhouse conditions by plant wizard Roy Herald.

[Lesley Cox]

A North Island friend gave me a pott of seedlings two years ago, said to be A. nepenthoides. But they are taiwanense, about 200 of them!

[Pascal B]

Johan, yes they indeed seem virus infected. I have found virus infected Arisaema galeatum in Neora Valley east of Kalimpong in West Bengal too but still a lot of things about viruses and their manifestation are unknown. One of the oddest things I have heard to combat virus in an infected plant is to spray it on a regular base with an aspirin solution..... Seems to decrease the infection rate but I can't find any published results of that research so best to get rid of these plants or at least keep them isolated from the rest of the collection. And keep aphids away from the plants.

Fimbriatum is a beauty in both its forms. True fimbriatum occurs primarily in Malaysia and is the bigger of the 2 with striped flowers, the one often called var. or ssp. bakerianum occurs mostly in S Thailand and lacks the stripes. Both not really "rock garden" plants but stunning nevertheless.

Fimbriatum is the only tuberous species within the genus with such an appendix, all others are rhizomatous and rare in cultivation. It is easy to grow as a house plant by the way...

Just to show you how unreliable colour and pattern is as a character in Araceae, see underneath of another form of Amorphophallus variabilis which is more salmon coloured than the one you showed. Evenly green forms also exist of this Amorphophallus which has a smell best described as truffle oil gone bad.... .

[Johan Nilson]

Pascal,
I will make sure to get rid of all plants that could be infected and to spread this information further on. It would be very bad if the virus would spread to other plants.

Great to see another form of Amorphophallus variabilis. It looks really nice! I find it very nice and interesting with the great color variation within species. Its great when you see both light green and almost black forms of the same species!

Your Arisaema fimbriatum var. bakerianum looks fantastic! I have noticed that our clone of Ariseama fimbriatum smells a bit like fish or salt water. Have you noticed the same with your var. bakerianum?

I would definitely like to grow var. bakerianum, both in our green house and of curse very much as a house plant! Wow, that would just be great!

Do you know if and where its possible to get hold of this variety?

I have a small Small tuber of Arisaema victoriae which I got from a friend last year. It is on its way out of dormancy now and I will try to grow it as a house plant in a east facing window. Any thoughts on how to grow that species?

[Pascal B]

Your Arisaema fimbriatum var. bakerianum looks fantastic! I have noticed that our clone of Ariseama fimbriatum smells a bit like fish or salt water. Have you noticed the same with your var. bakerianum?

No, it is odourless. Most Arisaema have sciarid rootfly as pollinators and therefore smell more like fungi to attract them. Exceptions are Arisaema sizemoreae which faintly smells of Narcissus and some yellow forms of Arisaema maxwellii that have a sweet, almost lily of the valley smell.

Do you know if and where its possible to get hold of this variety?

Send me a private message OK?

I have a small tuber of Arisaema victoriae which I got from a friend last year. It is on its way out of dormancy now and I will try to grow it as a house plant in a east facing window. Any thoughts on how to grow that species?

Although the short rhizomes of A. victoriae almost look like a tuber, they are still a rhizome and the worst thing to do with rhizomatous tropical Arisaema is to plant them too deeply, the rootzone needs to "breath" so pot it up in a very airy, humus-rich mixture just below the surface. Many rhizomatous Arisaema grow in the humuslayer with means a constantly moist air around the rootzone. Some plants of Arisaema filiforme I even grow in pure living sphagnum moss! Stagnant moisture will kill it. However, on a window sill these conditions are hard to achieve because the moisture level will fluctuate too much due to evaporation which would make regular watering necessary, compact the soil and squeeze out the air. I would advise not to grow this one on a windowsill despite the fact it has got leathery leaves, in general the tuberous species are easier to grow as houseplants than the rhizomatous species

[Johan Nilson]

Pascal,
First, thanks for your advice concerning Arisaema victoriae! I will try my best to give it suitable conditions.

Arisaema sizemoriae! . Its looks very nice, great spadix appendage. Its really interesting that it has a smell of Narcissus, wow! I found it also very interesting to hear that Arisaema maxwellii can have an lily of the valley like odour.

Are both of these new species? I cant seem to find any information about them, I have only got the first edition of Gusman- 'the genus Arisaema', maybe that's why?

There are a lot of great pictures of Arisaema maxwelli on IAS homepage, but I noticed that it was listed without auktors name. Is it jet to be described? 

[Pascal B]

Johan,

Both maxwellii and sizemoreae were described by Wilbert Hetterscheid with Guy Gusman as co-author in the Journal of the International Aroid Society (Aroideana 26: 39 (Dec. 2003)). The entire group these 2 species belong to seems rather variable so I sincerely doubt the species delimititations of these species indeed are as fixed as they are presented in their diagnosis. Both species were described based on cultivated plants of known origin but because they are samples from nature they could be just nodes in a variation range and several plants collected in other areas of Thailand show intermediate characters which causes me to doubt they are separate species.

But to search for a literature reference of any plant the best way of finding it is to do a search on www.ipni.org. In the old days one had to buy the Index Kewensis on CD, now everything is online so all information can be accessed by anyone interested, even if names in publications are not valid because they were not published according to the rules of the Botanical Code of Nomenclature.

The possible reason you couldn't find sizemoreae might be because I frequently misspell it as sizemoriae and even have labeled the picture of it that way..........

The plant on the picture by the way is the holotype clone of this species. Both species are named after 2 plant collectors that have done extensive fieldwork in Thailand and mainly collected Amorphophallus for the first author of these species.

[Johan Nilson]

Pascal,

Thanks a lot for the info! and for the link to the IPNI.

I will have to bye some of the back issius of Aroidiana right away!

[TheOnionMan]

Just emerging is a variable hybrid between Arisaema amurense (itself rather variable) and A. tashiroi, the latter a slender plant with distinctive snake-skin marked leaf sheathes.  The hybrids are much shorter and more stout than the slender A. tashiroi, but inherit the richly colored stems.

[Pascal B]

Mark, was this a controlled and intentional cross or a chance seedling?. If controlled, do you have pictures of the mother plant and the dad?

Generally I am not a big fan of man made hybrids in Arisaema because they complicate taxonomy and the offspring is rarely more attractive than the parents but documented hybrids at least give a clue to what might be a hybrid and what not. If you have this data I would be interested to know.

[TheOnionMan]

Mark, was this a controlled and intentional cross or a chance seedling?. If controlled, do you have pictures of the mother plant and the dad?

Generally I am not a big fan of man made hybrids in Arisaema because they complicate taxonomy and the offspring is rarely more attractive than the parents but documented hybrids at least give a clue to what might be a hybrid and what not. If you have this data I would be interested to know.

This was a chance seedling (actually, a number of seedlings with some variation).  I grow two forms of A. amurense, a robust one with green brownish-tinged flower (which the hybrids most resemble) and smaller all-green flowered ones, and rather close by I grew A. tashiroi.  A. kishidae was also there but that one died out a few years ago, however it remains a possibility this species is actually one of the parents... either parent could be responsible for the snake-skin marbled leaf sheathes that is not present on A. amurense.  I have sinced moved my A. tashiroi, where it seems happier and grows taller too.  I can post photos of both the hybrid plants flowering in 2009, along with A. tashiroi in 2009... will do so later on today.

[Lesley Cox]

The sheath is very attractive, as I find on all Arisaemas.

[TheOnionMan]

Following up on my post about Arisaema amurense x tashiroi hybrids, here are two batches of photos:

photos 1-5    A. tashiroi
photos 6-7    A. amurense - robust form, with brownish flowers
photos 8-10  A. amurense x tashiroi, emerging flowers and foliage


photos 11-14 (in a second batch)  A. amurense x tashiroi, full flower and foliage, last photo shows fruit.

Note:  the robust A. amurense has flowers that smell badly of wet dog.  Interestingly, the A. amurense x tashiroi hybrid has flowers with the same bad smell.