NEWS106
42
Plants
Thegorgeous flowerof
Ludwigiaadscendens
All photos:FrankSchäfer
equickly realized that itwasamem-
berof thegenus
Ludwigia
,which in-
cludes someof themostpopular aquarium
plants. There is even a species native to
Europe:theWaterPurslane,
Ludwigiapalustris
.
Unfortunately this species is in decline
everywhere, without the reasons being
known.Our native specieshasonlyvery in-
conspicuousflowersas itdoesn’tdevelopany
petals. By contrast the specieswe found in
Thailandwasnotable for itssplendid flowers,
agood3cmacrossand snowwhite incolor
apart fromyellowat thebaseof thepetals.
The genus
Ludwigia
belongs to the wil-
lowherboreveningprimrosefamily(Onagra-
W
Duringanexcursion in thevicinityof the townofPakChong incentralThai-
land,wecameacrossasmallpoolwithagorgeous floweringaquaticplant
whose identificationcausedusanumberofproblems.
ThemysteryLudwigia
bySarahNieten
Lexicon
Ludwigien
Ludwigia:Widmungsname fürden
BotanikerC.G.Ludwig (1709-1773)
palustris:bedeutet„imSumpf le-
bend“
helminthorrhiza:bedeutet„mitma-
denähnlichenWurzeln“
adscendens:bedeutet„kletternd“
hyssopifolia:bedeutet„mitBlättern
wieeinYsop“;Ysop ist eineandere
Pflanze
octovalvis:bedeutet„mit acht Fä-
chern“,bezieht sichaufdieFrucht
ceae),familiar inGermanymainly in the form
of theeveningprimroses (Oenothera),origi-
nally fromNorthAmerica.
Roots forbreathing
The
Ludwigia
thatwe foundnearPakChong
hadverycharacteristicrootsadapted foruse
as respiratoryorgans.Among the
Ludwigia
species known in theaquariumhobby, this
typeof root formation isvery typical for the
species
Ludwigiahelmintorrhiza
.
Ludwigiahel-
mintorrhiza
isaplantveryrarelycultivated in
the aquarium, as the species is extremely
light-hungry,but ifgrownsuccessfullythere-
ward isasplendidplant.Butusually it ispos-
sible to cultivate
L.helminthorrhiza
onlydu-
ringthesummer inasunnygardenpondand
very difficult to get the plant through the
winter.
L.helminthorrhiza
isn’tusuallyavaila-
ble intheaquariumtrade,butcansometimes
beobtainedfrombotanicgardens.It isnative
toSouthAmerica.
