Amydrium medium maybe?

Well , I believe this plant to be in the tribe Monstereae. Solely from comparing images am I going to suggest it is Amydrium medium. This plant is a scandent liane aroid with juvenile leaves and no infloescense.
This image is of the adaxial surface of the most mature leaf and shows a slightly bluish coloration. Mid rib and , Primary lateral veins sunken and smooth, loop connected, interprimary veins intersect with primary laterals, tertiary veins netlike . Lamina surface slightly coriaceous and quilted(bullate).

Thanks in advance for any help!

Scott

Abaxial surface lighter in color, midrib and primary laterals prominently raised and rounded.

Adaxial apical geniculum sulcate with 2 ridges, smooth and speckled

Abaxial basil geniculum.

Petiole and cataphyll ? I’m having a hard time with the cataphyll as it seems to be incorporated with the deeply sulcate petiole or is non existent. If someone can explain this to me that would be great.

Node

New leaf unrolling.

Thanks for looking.

Scott

Scott, I just did a search of every issue of Aroidena as well as all the scientific databases and can't find the description for this species. I sent a note to Pete Boyce in Malaysia asking if he can help us find a copy and I'll send it to you as soon as it arrives (if it is available). He is working on a book (soon to be published) that I believe will cover this species.

I have a specimen as well but zero information to compare to my plant.

Steve

Scott, the cataphyll appears to be a petiolar sheath which is not uncommon.

Look at any newly emerging leaf and see if their are small "wings" near the bottom of the previous petiole. These commonly become deciduous and drop off the petiole as the new leaf develops.

For anyone not familiar with the term cataphyll, a cataphyll is bract-like modified leaf which surrounds any newly developing leaf to protect the emerging new blade as it develops. A cataphyll may be unribbed as well as single or double ribbed and in some genera have important characteristics used to determine the species. A petiolar sheath is the same thing but does not develop independently from the previous petiole but instead on the surface of that petiole as you see on Scott's photo.

This message was edited Jun 12, 2010 1:24 PM

Scott, I just sent the description Pete Boyce has written for his new book The Flora of Thailand which has yet unpublished. It probably wouldn't be adviseable for me to post this publicly since the book is not in print.

Compare it to your notes above and let us all know what you think. I'm sure Pete wouldn't object if you make specific comparisons. .

According to Pete the species is found in southwestern Thailand, Southern Burma through Peninsular Malaysia and Sumatera to Java, Borneo, and the Philippines.

Steve

Well. I’m back from a short vacation and have had some time to ponder this plant while comparing it to Peter’s description that he and Steve thoughtfully provided for me. Thanks Guys!

There are two glaring differences between this plant and the description. The first being the petoliar sheath on this plant has a long (at least ¾ length of petiole), vaginate, inrolled sheath whereas the description of A. Medium is “petiolar sheath very short”.

The second is a lack of “Leaves often remote from one another with nodes between foliage leaves bearing papery cataphylls”. There is no indication on this plant of having the long flagelliform foraging shoots that are common on Amydrium. It is on these shoots that leafless nodes with cataphylls are present.

So, that sort of leads me to looking elsewhere in Monstereae tribe. I’m inclined to think that this plant will be a mystery until it presents more characters either through adult leaves or inflorences.

If anyone has a clue for me sent it on.
Thanks Scott

Bring good photos to the IAS show in September. I have a sneaking suspicion you'll find an ID there. This could easily be an Asian species and Pete will be in Miami so we'll sit with him and see if the mystery can be solved.

Steve