NEWS104
8
Floweringemerse shoot
temperatures between 14 and 25 °C, and
can thus be used equally well in cold-
water tanks, unheated domestic vivaria,
andaccommodation for tropical livestock.
But the temperature shouldbeallowed to
rise above 25°C only briefly, as otherwise
Bacopacaroliniana
will suffer problems.
Habitus
The Giant Bacopa is a typical stemmed
plant that can attain a length of some 40
to60cm.Likealmostall aquariumplants it
usuallygrowsout of thewater in thewild,
though it likes to have its bottom part in
water.This formofgrowth is termed semi-
emerse, ie half emerse. When a plant
growsentirelyon land it is termedemerse,
while when it grows submerged
underwater it is termed submerse. The
submerse formof theGiantBacopa isonly
rarely to be found in the natural habitat.
Aswell as theoriginal form there is also a
variant with reddish leaves known as
Bacopa caroliniana
"Variegata" (some
sources use this name for a white
blotched, so-called “mottled” form; but
neither is available in the trade). The
normal Giant Bacopa can also sometimes
develop reddish leaves. This is attributed
to lowphosphatecontent, lownitrate,and
bright lighting.Theunderwater formhasa
typical rich sheen reminiscent of various
succulent plants. The emerse foliage is
also very shiny: the stems of emerse
growth are densely covered with hairs,
and this means that emerse- and
submerse-cultivatedplants canbe readily
distinguished. If the leaves are rubbed
between the fingers or the plant is
pressed for aherbarium, then they release
an aromatic scent, reminiscent of lemons.
Propagation is either by offshoots that
format thebaseof themotherplant,orby
tip cuttings, which almost always root
withoutproblem.Removal of thegrowing
tipcauses theplant toproducesideshoots
anddevelopamorebushyhabitus.
Culture
The Giant Bacopa is light hungry; two
fluorescent tubes are advisable with a
water depth of 30-40 cm, and there
should be three if the water is 50-60 cm
deep.Otherwise there isn’t actuallymuch
that can go wrong during cultivation.
Bacopa caroliniana
requires neither rich
substrate nor CO2 fertilization, though
admittedly the plant grows best in soft
water. The substrate should be sand or
fine gravel, which is good for root
formationandencourages theproduction
of off-shoots. In summer theGiantBacopa
can also be readily cultivated in the
garden pond, where it will become
particularly beautiful and vigorous, but
the plant must be taken indoors in
October. If you want to use
Bacopa
caroliniana
in the paludarium then it will
suffice to plant tip cuttings in 5-10 cm of
water. The plant will then grow up out of
thewater anddevelop into the terrestrial
form, which, given a long photoperiod
(lighting formore that 12 hours per day),
will produceprettyblue flowers.Aquarists
can also enjoy the flowers if they allow
their plants to grow out of thewater.The
flowers are usually blue, with white
flowers occurring only rarely. They are
around 1 cm across and hermaphroditic;
