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Bladderwort - Mysterious "Air Shoots" of Utricularia
by Makoto Honda
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  Utricularia AIR SHOOT

Some aquatic species of Utricularia (in the section Utricularia) are long known to form filiform shoots branching out
from a stolon (horizontal stem), with a small rounded tip. These are termed "air shoots".
They grow underwater, floating near the water surface.
Air shoots are often produced in dense growth in such species as
U. inflata, U. macrorhiza, U. geminiscapa
, and others.
The exact purpose for the formation of air shoots is not known.

In time, the tip develops into a leafy organ, and becomes, not unexpectedly, leaves --- and bladder-bearing stolons.
 The original long shoot eventually melts away and a new plant is separated from the mother ship.
This appears to be a mechanism for vegetative reproduction of the species.

I do not know why this special mechanism is needed for asexual reproduction,
because even in regular branching from the main stolon, branches often detach themselves
 from the main body of the plant and become separate plants.
Maybe this is a rapid deployment scheme to produce multiple individuals in a short period of time.

I would consider air shoots to be a Utricularia version of "gemmae" seen in pygmy sundews,
or "scales" surrounding the winter bud of some temperate butterwort (in the same Lentibulariaceae family as bladderworts).


PHOTO:  Utricularia AIR SHOOT

Air shoots arise randomly from the Utricularia stolons.
Air shoots are often produced in dense growth. (Utricularia inflata)

PHOTO:  Utricularia AIR SHOOT

The round tip of a newly formed air shoot. (Utricularia inflata)

PHOTO:  Utricularia AIR SHOOT

The tip becomes larger and a leaf structure emerges. (Utricularia inflata)

PHOTO:  Utricularia AIR SHOOT

In time, an air shoot develops into -- you guessed it -- another bladderwort. (Utricularia inflata)


PHOTO:  Nikon D300 + AF-S Micro Nikkor 60mm F2.8 + Flash

Carnivorous Plants Photography Web Site:  Copyright 2001-2018 Makoto Honda. All Rights Reserved.  

Copyright 2001-2018 Makoto Honda. All Rights Reserved.                                                                    since June 2001