categoryZClimbers Climbers List 

GREATER DODDER

Cuscuta europaea

Bindweed Family [Convolvulaceae]

month8jul month8july month8aug month8sep month8sept

category
category8Climbers
status
statusZnative
flower
flower8white
 
flower
flower8pink
 
inner
inner8pink
 
morph
morph8actino
 
petals
petalsZ5
(4-5)
type
typeZglobed
 
stem
stem8round
 
smell
smell8rottenfish
fishy
rarity
rarityZscarce
 
sex
sexZbisexual
 

3rd July 2014, unknown place. Photo: © Bastiaan Brak
Parasitizing Stinging Nettle, it's favourite.


3rd July 2014, unknown place. Photo: © Bastiaan Brak
Has red stems, but you cannot rely on this feature for identification because Dodder also has red stems. And you can't anyway: sometimes the stems are green or yellow-green, as here.


29th July 2008, unknown place. Photo: © Dylan Warren-Davis
Parasitizing Stinging Nettle. The lime-green colour of this nettle is probably because the photograph was flash-illuminated? No Dodder kills the plants it is parasitic upon, it just taps some of the nutrients.


3rd July 2014, unknown place. Photo: © Bastiaan Brak


3rd July 2014, unknown place. Photo: © Bastiaan Brak
the red flowers are opening and turning paler.


3rd July 2014, unknown place. Photo: © Bastiaan Brak
Dodders even entwine around themselves. It looks like Dodder spirals around plants in am clockwise direction as it grows longer.


3rd July 2014, unknown place. Photo: © Bastiaan Brak
The flowers are at intervals along the stem and in small globular clusters, unlike those in the night sky which are really rather big!


3rd July 2014, unknown place. Photo: © Bastiaan Brak
The sepals are red with 4 to 5 teeth. The petals might be pale-green below.


3rd July 2014, unknown place. Photo: © Bastiaan Brak
There are two styles within plus 4 or 5 anthers.


Easily mis-identified as : Dodder (Cuscuta epithymum) which also has red stems, is a bit less rare ([R]) than Greater Dodder's [RR] rating, always has 5 petals (unlike the 4-5 of Greater Dodder). To differentiate between the 3 species of Dodder the length of the styles in comparison to the height of the ovary must be carefully observed, as well as the presence or absence of a small round stigma. This means having opened flowers to tell. Almost uniquely identifiable characteristics

Distinguishing Feature : Instantly recognisable as one of the Dodders, but which one...

Greater Dodder feeds parasitically primarily on Stinging Nettle (Urtica dioica). It likes to be near water, is decreasing in occurrence and is found locally in England south of Peterborough. It is not common and really quite rare.

Although your Author has given it a heading of a 'climber' (on account of the coiled spirals that wrap and tighten their grip on host plants) it does not seem to be able to climb by means of the tendrils, although it can hang from the branches of trees and shrubs by this means.

Unable to synthesize chlorophyll, Dodder is a  hemi-parasitic plant which is parasitic on other plants an depends upon them for all its nutrients. It sprawls all over suitable plants, tapping into their resources via haustoria which insert themselves into the host plants. It twines anti-clockwise around the host plant, tightening the loose coils as it does so which initiates the growth of the haustoria on the coils to tap into the plant. The host plant is usually Gorse, but Heather and Wild Thyme are also likely hosts. After tapping into the host, the plant continues to grow loose spirals until they too find a host and the coils tighten again to gain nutrient contact. Dodder plants do initially possess their own roots, but they soon die off once they have tapped into the food supply of a host plant. If, however, the Dodder fails to find a suitable host within 2 to 5 days of germinating from seed, then the Dodder will die. Once it is successfully attached to a host plant it will grow and spread to cover other distant plants, possibly tapping into those too. Although an annual itself, if it taps into a perennial galls can form at the attachment areas over the winter, and when spring arrives new Dodder plants can develop from these galls.

Dodder detects the presence of certain desirable host plants by the volatile organic compounds that the host produces, and is able to home in on the host plant, wrap its tendrils around it and tap into it if it deems the host beneficial. But the host plants are not defenceless in this attack, and often synthesize deterrent and toxic molecules (phytoalexins) in response. Dodder does possess leaves, but they are minute and scale-like, and, lacking chlorophyll, not green. Dodder is thus holoparasitic, unable to photosynthesize it must parasitize to obtain all its needs.

There are several other Dodders, one, Greater Dodder (Cuscuta europaea) ([RR]) is rarer than Dodder ([R]) and prefers Stinging Nettle (Urtica dioica) (but unlike Dodder is able to parasitize almost any other plant within reach) but Yellow Dodder (Cuscuta campestris) is apparently not rare but rather a non-native garden escapee which prefers to parasitize Carrot.

Somewhat surprisingly, some parasitic plants are able to parasitize themselves, a phenomenon called self-parasitization. Species of Dodder are one such, Mistletoe too in some instances.

There are reports that Dodder smells foul (reminiscent of rotting fish) when it is flowering and those flowers are ripe for pollination. At other times there is no detectable odour. One of it's colloquial synonyms is 'Devil's Guts', which explains a lot. Rotten fish smells of amines, so Dodder must emanate amines during those periods. It seems that the plant uses the rotting smell to attract blow flies which will then pollinate the plant. One of those amines could well be either Putrescine or Cadaverine or even both together.


  Cuscuta europaea  ⇐ Global Aspect ⇒ Convolvulaceae  

Distribution
 family8Bindweed family8Convolvulaceae

 BSBI maps
genus8Cuscuta
Cuscuta
(Dodders)

GREATER DODDER

Cuscuta europaea

Bindweed Family [Convolvulaceae]