| Introduction
The genus Utricularia
(pronounced 'you-trick-you-laa-ree-ah') has over 200 species,
and is therefore the largest genus of CP known. Its geographical
spread is also large, covering most areas of the world. Like
Drosera, Utricularia are missing in only the Arctic and
Antarctic regions of planet Earth.
Understandably for such a large genus, the
species do not all share common habitats: some prefer
terrestrial life, others aquatic, while a few live
epiphytically - without soil. However, most have blooms that are
comparable in beauty and, some may say, even exceed that of some
of the prettiest Orchids! All have the same trapping mechanism -
the mechanism that has led to Utricularia being more
commonly known as the Bladderworts. Hobbyists also refer to the
plants using a shortened version of their genus, Utric.
As an collector of Insectivorous
plants for a number years, I have found that you will get some
of these plants growing in the pots of other carnivorous plants.
One of the main plant that I have found to do this is U.
subulata , which as very nice yellow flower. they will not
harm the other plant at all. I have also seen that were
other plants grow, normally you will find these plants too.
Trap
No matter whether the Utric lives in
soil, water or air, the basic concept of trapping is the same.
Although no Utric has a true root system, they do have stems
capable of photosynthesis and that scramble to fill whatever
region they find themselves in. These stems also carry the trap,
a hollow bundle of cells anything from a less than a millimetre
to around a centimetre (fractions of an inch to half an inch) in
diameter. The traps are like balloons with extensions from where
you would blow the balloon up, with the air hole of the balloon
being sealed tight by a viscous fluid.
The sides of the trap are usually
concave, and therefore create a vacuum within the interior of
the trap. Hairs protrude from the extensions from the trap, and
should these be stimulated by a passing creature - usually a
small aquatic animal - the trap is sprung. The sides of the trap
suddenly become convex, possibly using the same method as
adopted by VFTs, and whatever animal has stimulated the trap
finds itself sucked into the trap in much less than a second.
From here, the plant uses secretions of digestive juices to
break down the captured prey and absorb the resultant minerals.
D'Amato graphically describes the fate
of larger prey, such as tadpoles, who are likely to be caught
initially by the tail but are too big to fit into the trap
whole. In this situation, the plant will feed off whatever part
it has caught, while the struggling animal repeatedly triggers
the trap to suck more and more of the helpless creature further
into the burning acids.
Types of
Utricularia
As with so many intra-genus
groupings, Utrics are split into pretty arbitrary groups. Here
is present one method of performing this grouping, by looking at
terrestrial, aquatic and epiphytic species separately.
There is a full list of known named plants at
this time below with helpful key to help you.
Note: The now discontinued genus of
Polypompholyx named in many great older books now falls
under the Utricularia genus.
Terrestrial species:
These species are found all over the
world, wherever the plants can enjoy permanently wet soils and
occasional shallow flooding. Popular examples of species in this
category are U. sandersonii, U. subulata,
U. busquamata and U. livida amongst many others.
Aquatic species:
These species are found floating
in water, and require no connection to land in order to survive.
While most plants make their home in ponds, a few prefer to grow
within in the rainwater collected by the leaves of other plants,
such as Bromeliads. In colder temperatures they tend to die down
to hairy buds, ready to burst into active growth once the
temperature rises once more. Examples of species that lie in
this category are U. vulgaris, U. minor,
U. purpurea and U. gibba.
Epiphytic species:
These species are neither found in soil
or free-floating in water, and rather are at home growing in
moss, on bark, on top of leaf debris or even clinging to rocks.
Most of the species in this group survive drought by growing
again from tubers created during wetter months. Popular species
in this category include U. reinformis, U. alpina,
U. humboltii and U. longiformis amongst
others.
In the Wild
With such a wide geographical spread,
it is not surprising to find that some species are thought by
some as CP weeds, while others rather rarer. Nevertheless, it
should be stressed that no matter how common any plant, be it
carnivorous or not, are in an area, they should not be removed
by any collectors. Exceptions of course occur when those
removing plants are botanists or connected scientists doing so
for research and/or conservation.
In Cultivation
Utric's are popular with CP enthusiasts
due more to their pretty, delicate-looking flowers than their
carnivorous nature. For, although the trapping mechanism is
spectacular it is difficult to even see most of the traps with
the naked eye, let alone fully savour the quickness with which
it can despatch prey! In terrestrial species especially, the
traps are below ground - leaving no indication of the real
goings on of plant above soil level.
Whilst these plants are easy to grow,
it is probably this lack of visual carnivory which has seen them
notable by their absence from most garden centres. I myself have
only ever seen U. sandersonii on sale in garden centres, but I
would recommend this plant as an ideal starter Utric for any CP
lover.
Terrestrial species are best kept in
the CP growers near-universal soil mix: 1 part sphagnum moss
peat to 1 part sand. Aquatic species thrive in water mixed with
a small amount sphagnum moss peat while epiphytes like an airy
mix of sphagnum, perlite and peat, with emphasis on the former
two ingredients. Most Utric's appreciate sun, which will help
with their flowering.
As for propagation, most species will accept
growers literally tearing pieces off the plants and placing into
fresh media. Utric's are almost the fool-proof CP! They will
also grow quite happily from seed.
Further Reference (
See larger book list on this site. )
D' AMATO, P.: 'The Savage Garden' (Ten Speed
Press 1998) pp219-235
DARWIN, C.: 'Insectivorous Plants' (Langford
Press Reprint 2002) pp395-453
LLOYD, F. E.: 'The Carnivorous Plants' (Dover
Publications Reprint 1976) pp213-270
SCHNELL, D. E.: 'Carnivorous Plants of the
United States and Canada' Second Edition (Timber Press 2002)
pp332-394
SLACK, A: 'Carnivorous Plants' (Marston House
Reprint 2001) pp165-181
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