Arisaema 2011

[Pascal B]

It might sound odd for some to start a new thread for Arisaema already but Arisaema section Clavata contains members that are all early flowering, they usually start rooting in the autumn. This section includes ilanense, heterocephalum, hunanense and clavatum itself but in my view also includes Arisaema negishii. They generally grow at low to medium altitudes in the wild. They are temperate species but usually do not experience frost in their native habitat. When most spring flowering species come into flower the members of section Clavate are usually already dormant.

Arisaema ilanense is a Taiwanese endemic and, although locally abundant, has a very limited distribution range that is not more than perhaps 5 km2. It grows on shady slopes, usually in a humus rich slate. In the wild the flowering period is from end January to end March. The plant on the picture I forgot to move to the frostfree glasshouse so it is a bit earlier. By some this species is regarded one of the more naughty members of the genus given the shape and size of the spadix appendix.

I hope to post pictures of more members of this section when they start flowering.

Arisaema ilanense Jan 2011.jpg

[Lesley Cox]

Perhaps someone will identify this species for me, given to me last season as a dormant tuber, named A. flavum but obviously not. I have another not yet out just as Arisaema ?species, which appears to be the same. Remember that this is mid summer in New Zealand but I took the photos today on a dark, wet day, the only day I've ever used my 5 year old camera and the flash has gone off of its own volition, so dark as mid winter! Because of the flash, the spathes appear rather more shiny than they really are. I like it very much and the two leaves are very fine too. It is potted and in my tunnel house so protected from the hot days and strong winds we've had and looking very elegant I think.

[Diane Clement]

Perhaps someone will identify this species for me, given to me last season as a dormant tuber, named A. flavum but obviously not.

Lesley, I think it might be A fargesii but maybe Pascal will confirm

[Lesley Cox]

I'd be very happy with that, not one I've ever had or expected to have.

Thanks.

[Diane Clement]

I'd be very happy with that, not one I've ever had or expected to have.   Thanks. 

Here's mine for comparison, which I think is A fargesii although it is possibly A franchetianum.  The leaves are distinctive and very large

[TheOnionMan]

I have one that I got some years ago, it never ever flowers, just makes one big leaf that looks just like the one pictured, it is either A. franchetianum or fargesii, but as we have a meter of snow on the ground, can't check labels.  I wish it would produce some of those beautifully striped flowers.

[Pascal B]

Although I think the current treatment of both species is not great and needs more study (particularly fieldwork), by current standards the plant of Lesley is fargesii, the plant of Diane is franchetianum.

The original diagnosis for franchetianum is pretty clear, the one for fargesii is not so at the moment everything not franchetianum "must be" fargesii but what fargesii exactly should look like I still am not sure of and none of the current treatments can convince me, neither Gusman or the FoC. The original Vilmorin plants that formed a large part of the basis of the name fargesii only were clear for the male plants and the female plants seem to differ the most within this group. I actually think there are more taxa than just these 2.

These plants already fall into 2 groups with one having more rounded and soft leaves and the other with more leathery leaves and pointed tips. Within both groups several spathe shapes occur and some of these plants have such unique characters that by normal standards that would qualify them as a distinct taxon. Problem is that very few plants in cultivation have known provenance, most are descendants of recent Chinese imports and we do not know enough about the variation in the field to judge how unique these characters are. I have 6 very distinct "forms" in my collection and I discussed them with Peter Boyce who seriously doubted they would all fit in either franchetianum or fargesii. But the plants of Diane and Lesley are the more regular forms in cultivation and by current standards are franchetianum (Diane) and fargesii (Lesley)

[Pascal B]

To show what I mean, Arisaema "purpureogaleatum" is synonimised by Gusman and the Flora of China with franchetianum. However, the highly inflated spathe, the long spathe tip and portruding appendix (in need of Viagra....) make it very distinct and conform the description & drawing by Engler. In my view Arisaema purpureogaletum therefore is a valid species and the synonimisation is incorrect. And that is just one distinct form.

Arisaema purpureogaleatum.jpg

[Lesley Cox]

Thankyou everyone. For now I'll relabel my plant as A. fargesii. I also have from the same donor, A. franchetianum but it is not flowering this year so I can't make a comparison. The foliage and stems look the same though.

[Diane Clement]

Although I think the current treatment of both species is not great and needs more study (particularly fieldwork), by current standards the plant of Lesley is fargesii, the plant of Diane is franchetianum.

Pascal, I am really grateful to you for this explanation.  My plant had actually been identified a couple of years ago by Gusman as franchetianum but I was never really convinced as to why it wasn't fargesii.  Are you looking at the leaf structure/shape as the picture of mine does not give much information?  I have several pots of this group all with very large leaves and similar but slightly different flowers and I have never really been happy about the identification of them all. 

[Pascal B]

Diane,

If you read my posts on Arisaema taxonomy you might think I doubt the treatment of all species.... Although not true, it is not far from it. Almost every species I have studied in the wild revealed new data that doubted the treatment of that species and was showing there is still so much to learn. The fact of the matter is that 60% of the known Arisaema are highly variable and there is still a lot of work, particularly fieldwork, to be done.

Although any publication is a representation of current knowledge, the definitive nature of some of these publications I feel is unjustified as it is clear by most researchers doing work on Arisaema that there is still so much to learn and stating "it is" would be premature and a bit arrogant. Often authors present their views in such a way only to gain credibility but that gives false security.

Your franchetianum I am very familiar with as I grow that "weed" myself, I multiplies like mad and comes in a purple and a purple-red form, it is pretty much conform what franchetianum is according to the original publication. The spathe blade is broad and strongly recurved with an appendix that hardly portrudes the spathe mouth, the spathe tip is usually nearly touching the spathe tube. Attached a picture of a similar plant in my collection that is more reddish purple and has a slightly shorter spathe tip. But other than that pretty much the same. The fargesii-type is considered to have a much less recurved and more "open" flower with more auriculate spathe mouth and a spathe tip that gradually narrows whereas the spathe tip of franchetianum narrows abruptly. But there are intermediate forms......ahum....

The challenge is to find out which flower characters are varying and to what extend and for that we can not base conclusions on samples in cultivation, instead we need population studies in the wild. It also involves taking phytogeography into consideration for example as well as the naughty bits inside the spathe and comparing that data with the original descriptions, holotypes and revelant publications. With ~160 species that is a lot of work and unfortunately very few doing it and even less researchers coorperating....

[manicbotanic]

this opened on christmas
 day ..kept in an unheated room..in a very cold house.
arisaema rhizomatum i believe?

[Pascal B]

Yep, rhizomatum is one of the nicest species introduced from China with those beautifully spotted flowers. Not the easiest to grow though...., it should be grown as you did, cold but frostfree.

[Hoy]

Anybody who has a clue to this one?

[Pascal B]

Anybody who has a clue to this one?

Do you have close-ups of the flower? It looks like a member of the asperatum/wilsonii alliance, a plant Chen Yi used to ship under A-10.