Myrmecodia cf. pulvinata

[Philpatrick]

 

Myrmecodia cf. pulvinata notes and images.

 

Here are some observations on a Myrmecodia cf. pulvinata; to see how it compares to Myrmecodia tuberosa "pulvinata" and possibly find out more about the origin, identity and characteristics.

 

The plant has been growing in a terrarium under grow lights. It is growing fast and large. When the  flowers emerge, to me, it looks like molars surfacing through gums. The characteristics I find most interesting are the translucent petioles that are sharply keeled and the clubbed spines.

 

Myrmecodia tuberosa "pulvinata" is noted to be a heterostylous species. Some plants of the population will produce brevistyle flowers and some plants will produce longistyle flowers.

 

After examining the flower, it appears that this particular plant is producing longistylous flowers with a long style reaching to the apex of the corolla. The anthers were expired and it was difficult to determine a location. The anthers did not have any pollen when I checked the flowers, so I have not noticed if this plant has the characteristic pollen with a single vesicle (fluid filled sac). The bottom of the corolla had a ring of hair like a whisker biscuit, like those used in archery for holding the arrow.

 

I noticed something  strange about the flower; there was a "shield" of flower tissue capping the corolla with the stigma pressed against it. More detailed images can be taken when it's next flower matures.

 

Another thing I noticed, is that ants have been putting debris around and on top of the flowers. 

 

Also, the flowers have roots surrounding them on the alveoli rim. I think the high humidity in the terrarium could be causing the aerial roots to develop. The caudex has several aerial roots as well, the stem does not have any roots. I am not sure how Anthorrhiza derived that name but doesn't Anthorrhiza translate to flower-root? Is this a trait of Anthorrhiza also? Has anyone noticed roots growing around the alveoli and flowers of other species?

[jeff]

Bonjour

have you a picture from the whole plant ?

spines seems to be  modified advantivious roots ,there is also a gradation from spines to roots .

a lot of rubiaceae have often spines around the alveoli where you have  often  flowers

 

[Philpatrick]

Here is the entire plant. The largest leaf is 8x23 cm with the petiole.

The base spines are club shaped then gradually transition into single spines on the stem. There is an inline ridge of spines beneath the petioles. There aren't any clypeoli.

Alveoli pairs. 

This plant has been noted to have orange fruit and not pink fruit. 

 

 

[Frank]

Very impressive photos Philpatrick!  Thank you very much for posting these.  The quality of these photos is exceptional.  I particularly like the lighting you have on the close-ups

We hope you will continue with this study of the species and discover more information on some of the issues you raised - like the reason for the plug?  Is it on all the flowers?  Does it come off?  Are the material the ants put on the plug their droppings or some other kind of material? 

Excellent work!  Thanks again.

[Philpatrick]

Thanks Frank. I did get images of the latest flower and, hopefully, get a better understanding of the flower anatomy and breeding mechanisms. This time there was pollen and the anthers were not dehydrated and expired. Now I can see that the anthers are located at the apex of the corolla just below the petals and not low in the corolla like I thought originally, assuming all flowers are the same. The closed stigma was still developing positioned just below the anthers. 

The flower with one quadrant dissected to the ring of hairs.

 

This is my view of the flower structure:

It appears the unci delaminate and split leaving the upper portion open in quadrants forming the inward pointing hooks and appearance of an open flower. The lower portion of the petal delamination has an exposed cell granular surface capping off the flower; with the apex of the inner floral cavity portion remaining fused. The flowers have never opened so far on this plant. I am hoping this makes sense.

Cut-away of a petal quadrant exposing a pollen sac.

I have been comparing the M.tuberosa "pulvinata" drawings by Rosemary Wise to this plant, good artwork, all of it, and the flowers of this plant look different. They almost look like they have M. tuberosa "papuana" influence. With this new flower the anthers are not located in the characteristic location for M. tuberosa "pulvinata", just above the ring of hairs and are located high in the corolla.

In the first flower I opened,  the breeding mechanism did not seem facilitative of self fertilization, with the anthers maturing and expiring before the stigma was open and fully developed ( protandry ). I'm not sure if there is a fertilization "window" to self pollinate, but I have a creative idea to image this. In this new flower, with active anthers and pollen, the closed stigma is just below the anthers.

The ant species scouting around this plant have been known to take refuge in plant cavities naturally, and is not a stinging species. I can get an image and the species name of the ants too. Perhaps not a species of ant the plant would encounter in nature but they love this plant. My guess is the debris on the flower tops is the ant refuse pile made of excavated fragments from within the alveoli cavities. I will have to look closer.

[Philpatrick]

I should mention that the name of this plant is noted as Myrmecodia cf. pulvinata.

With a "cf." (short for, Latin: confer, "compare with").

 

[jeff]

Bonjour PHILPATRICK

they are ants from your home that colonized your plant ?

do you have a picture in section of the inside of the flower but vertical (from bottom to top) to better see the position of the anther, the ring of hair, the stigma?

how many lobe on the stigma ?

Myrmecodia cf. pulvinata  ; do you mean Myrmecodia tuberosa cf 'pulvinata'

[Philpatrick]

Hello Jeff,

The ants are a local non-invasive species. So just by chance I make observations if they happen to be around. The plant has been moved to a lower humidity environment; to see if this causes more spines to devlop than roots. The ants have gone since. Cinnamon has been used to treat orchids for fungal and bacterial problems. I use cinnamon sparingly as an ant and pest deterrent but mainly to protect flowers from being eaten by ants. Sometimes the ants eat the entire flowers of my Myrmecodia.

Cinnamon oil can be phytotoxic, to some plants, so I am cautious and test it on a leaf first.

Because cinnamon can be phytotoxic and can have herbicidal action, I am only going to use it as an ant barrier and not on plants.

The flowering has stopped for now. A dried flower is rehydrating to get a stigma lobe count and cross section, or just wait for a new flower.

I hand pollinated one flower and it looks like there is some fruit developing in a few spots. If this is fruit developing, it could be that the flowers are cleistogamous or have been pollinated by ants or an unknown pollinator. For the next flowers I am keeping the ants and possible pollinators away, and taking better notes.

Are the flowers cleistogamous or do they remain closed to select a particular pollinator? Both? Protandrous?

The plant is labeled "Myrmecodia cf. pulvinata". 

 

[jeff]

Bonjour

rarely cleistogamous and sometimes heterostylous .

may be  selfpollinate , pollinate by the ant although ants are ' piétre'( in french I can not find the right word in English)pollinator , may be also by the wind or other critters

where did you get your 'pulvinata'  ?

this label Myrmecodia cf pulvinata   for my part is not correct, rather cf tuberosa 'pulvinata', pulvinata according to Huxley and JEBB is part of tuberosa, it is not a species apart ,or simply

Myrmecodia  sp ,when you are not sure of his determination

 

[Philpatrick]

It looks like the stigma has 3 lobes.

[jeff]

3 lobes  , the taxon seems to have 5 or 6  ?

[Philpatrick]

It has five lobes.

And an orange fruit.

[jeff]

excellent picture

the stigma was at the same level as the anther ?

 

on the tuberosa 'pulvinata'

the anthers just above and touching the hairs 

in longistyle flowers stigma at the tube apex

in brevistyle flowers stigma at the same level as the anthers

stigma 5 or 6 lobed

fruit pink

 

 

[Philpatrick]

I had flared out the stigma lobes to get a stigma lobe count.  

The three lobe count was actually from another myrmecodia; this other plant has a stigma with six lobes but fused in pairs to look like three lobes. I had it stored in an unlabelled vial. I wasn't sure if it was from this plant, now I know it is not.

The flower image above is from a freshly extracted Myrmecodia cf. pulvinata flower that was not stored in an unlabelled vial and no room for error. 

At first the stigma resides closed in the space between the ring if hairs and the anthers. Then as the anthers expire the stigma elongates and opens into the space where the pollen and anthers are and reaches to the apex of the floral chamber. Much like a protandrous flower. I have read that protandry is also a method to spatially facilitate the development of the pollen release stage and then the stigma receptivity stage; to allow each stage to have the space to develop properly.

[Philpatrick]

The small green unripe fruit did grow and become orange quickly!

Literally overnight as mentioned in this post:

http://myrmecodia.invisionzone.com/gallery/image/19-m-salomonensis-ripe-fruit/

 

[Philpatrick]

On 2/21/2019 at 7:28 PM, Frank said:

Are the material the ants put on the plug their droppings or some other kind of material? 

Here's one of the piles of debris the ants placed around the alveoli. They seem very content and happy. As the fruit expands outward the ants progressively remove the rim on the fruit, the developing fruit are unharmed. They explore the flat top of the fruit often with their antennae.

The pile is basically every component of the complex potting media I used for this plant along with what looks like flower pieces ( It is actually ant exoskeleton molts ) and moss.

There is also a pollen sac in one cavity.

12 hours later, the fruit in the lower part of the image above is already expanding and ripening.

[Philpatrick]

The seeds from the fruit germinated and are developing nicely. 

The seedlings have large cavities compared to their size.

 

At first there is not an opening and the hypocotyl is smooth. 

The thin surface of the caudex, where the opening is forming underneath, sheds away to reveal a cavity at their base.