[ninsekaya]

Hi APC folks,

I am a newb to this forum and really appreciate all the amazing knowledge that is shared through this community. I have been playing with plants (both aquatic and terrestrial) for at least a decade now but have only been in the hobby for a couple of years.

Anyways, I love the whole Araceae family, so naturally my interests gravitate towards the Cryptocoryne and Bucephalandra genera.

Now to my observation/question...Over the last few months I have noticed that small pieces (~1/8") of rhizome from C. wendtii will get caught in between blades of Eleocharis. When this happens and they are able stay there long enough they will slowly send out a root or two and begin to slowly bury themselves beneath the substrate. Simultaneously they will grow a new leaf and vuala! The plant has colonized new territory! Having not taken plant physiology in a while I was wondering what mechanism allowed a sessile organism to "move" in this way? I haven't seen any other Cryptocoryne species do this but was wondering if anyone else had witnessed this cool behavior?

Much Thanks - Kaya

 

[Michael]

Welcome to APC!

What you see is called fragmentation, a form of asexual reproduction in which small pieces of the plant break off, drift to a new location, and slowly grow into a complete plant. It is reasonably common in aquatic plants, but we often miss it in our aquaria because we tend to clean up all these little bits. It is a pretty tricky dispersal mechanism.

 

[ninsekaya]

Thanks for the response Michael. Indeed, many aquatic plants are hydrochoric. What fascinated me was the self-burial mechanism in this Cryptocoryne sp. I am familiar with the mechanics of self-burial of some terrestrial plant seeds whose morphologies respond to humidity changes from the surroundings. To witness it in an aquatic plant is quite fascinating because this fragment lacks the hygroscopically active awns of the Geraniaceae genera I know of. I'm guessing theres some kind of contractile rotation and a helix structure involved as the root cap moves through the substrate...but that's really just a guess.

 

[JSeymour]

Great observation, I've experienced the same with C. xwillisii. Some Cryptocoryne spp. do have highly contractible roots, utilizing transverse rings, to put the plant deeper into the substrate. Not all species have them however. Some of this info can be found on Jan Bastmeijer's site, The Crypt Pages.

 

[Kai Witte]

Jason is correct that contractible roots allow a lot of crypts to settle their rhizome into the soil at a suitable depth; after seedlings establish themselves at the surface, many aroids utilize this to get their tubers/rhizomes deep into the soil. Same-o for many other plants.

The transverse rings is what you see after the roots contracted.

 

[tiger15]

I have no idea what Araceae is until I search the web. The genus includes many popular terrestrial ornamental plants and aquatic plants such as Anubias, Buce and Crypts. Surprisingly, duck weed is also Araceae .

http://www.aroid.org/genera/

I thought Crypts is a rosette plant and didn't know it has rizhome. Does it mean it can be attached to rock and driftwood and grow like Anubias and Buce.

 

[Kai Witte]

I have no idea what Araceae is until I search the web. The genus includes many popular terrestrial ornamental plants and aquatic plants such as Anubias, Buce and Crypts. Surprisingly, duck weed is also Araceae .
http://www.aroid.org/genera/

Araceae is the family (which includes many aroid genera); genus is more like a human "family name" (and placed first like in many Asian countries). The species name consists of the genus and a "given name": Cryptocoryne cordata [genus: Cryptocoryne, species: C. cordata].

I thought Crypts is a rosette plant and didn't know it has rizhome.

Most rosette plants have a rhizome/tuber (only rarely a bulb as in Crinum); it may be short and growing vertically/slowly though.

Does it mean it can be attached to rock and driftwood and grow like Anubias and Buce.

Actually, you can do this with quite a few crypts, too. However, it certainly is not their preferred live style and they will send their roots down into the soil and escape by sending out runners...