What's This Structure?

**T* H* <o*@gmail.com>**

Dear wise people,

This plant is ostensibly the water aroid Cryptocoryne balansae, but
may be better described as C. crispatula, var. balansae. Regardless of
actual identity, this plant seems to like to develop curious
adventitious rootlike structures at old leaf nodes per the picture.
The ruler is denominated in US inches.

The structures are limited in size to about what you see. They appear
on specimens growing submerged. Further, they always extend upwards in
the water column, not down. They are not especially long-lived,
generally falling away as another leaf node is exposed following the
death of the oldest leaf on the stem. This Crypt variety is consistent
with these structures and I've not seen many others, if any. It might
be diagnostic of the clone. One theory I have is that they may be
adapted to gather and pump in oxygen from the water to aerate roots
growing in anoxic conditions.

Ideas anyone?

Ted Held.