categoryZGallsAndRusts Galls And Rusts List 

COMMON MEADOW-RUE

Thalictrum flavum

Buttercup Family [Ranunculaceae]

month8jul month8july month8aug

status
statusZnative
flower
flower8yellow
inner
inner8cream
petals
petalsZ4
type
typeZclustered
stem
stem8round
stem
stem8fluted
toxicity
toxicityZmedium

2nd July 2011, sand dunes, Crosby, Sefton Coast. Photo: © RWD
In a temporarily dry but normally wettish hollow. Grows to 1m high or more.


2nd July 2011, sand dunes, Crosby, Sefton Coast. Photo: © RWD
Flowers have a fuzzy clustered appearance and a creamy colouring, easily mistaken for Meadowsweet from afar.


2nd July 2011, sand dunes, Crosby, Sefton Coast. Photo: © RWD
The flowers give the impression of being a mass of golf-ball-sized spheres of cream coloured fuzz.


17th June 2014, Crag Foot, Warton, Lancs. Photo: © RWD
A typical stem with leaves facing inwards and upwards and a fuzzy inflorescence atop.


2nd July 2011, sand dunes, Crosby, Sefton Coast. Photo: © RWD
But closer inspection reveals that they are at most hemi-spherical.


8th June 2016, dunes, Hightown, Sefton Coast Photo: © RWD
Before the flowers have properly opened and dangled their long male parts


8th June 2016, dunes, Hightown, Sefton Coast Photo: © RWD
Close-up of young un-opened flowers when the sepals can be better seen.


8th June 2016, dunes, Hightown, Sefton Coast Photo: © RWD
It can be gathered from this photo where some flowers are closed with long greeny-cream anthers still within the sepals and others next to them where the filaments have yet to grow rapidly, as they do.


2nd July 2011, sand dunes, Crosby, Sefton Coast. Photo: © RWD
The flower is seen to consist mostly of white stamens bearing long axial cream-coloured anthers which project upwards or outwards from four white petals.


2nd July 2011, sand dunes, Crosby, Sefton Coast. Photo: © RWD
The four white petals/sepals, which drop off sooner than do the stamens.


17th June 2014, Crag Foot, Warton, Lancs. Photo: © RWD
A clear view of three compound flowers without plucking: the one on the left still developing within the whorl of 4 pale-green sepals, the short filaments yet to grow much longer. The two on the right with now paler petal-like sepals cupping between 2 to 15 carpels with short white paddle-shaped stigmas atop and numerous much longer filaments with long pale-yellow anthers atop.


17th June 2014, Crag Foot, Warton, Lancs. Photo: © RWD
Stamens splayed apart on this inflorescence to better show the much shorter white stigmas. The sepals drop off naturally.


2nd July 2011, sand dunes, Crosby, Sefton Coast. Photo: © RWD
The stems are angular with four or eight faces in places. Short narrow bracts peel away at stem junctions. Even shorter 'hairs'. Stems look square here.


8th Aug 2015, sand dunes, Hightown, Sefton Coast. Photo: © RWD
Seed pods developing, yellowish-green at first.


8th Aug 2015, sand dunes, Hightown, Sefton Coast. Photo: © RWD
In numerous small bunches.


8th Aug 2015, sand dunes, Hightown, Sefton Coast. Photo: © RWD
Tipped with a brown termination, a dead bit of the flower.


8th Aug 2015, sand dunes, Hightown, Sefton Coast. Photo: © RWD
Of many differing sizes, but fattening.


8th Aug 2015, sand dunes, Hightown, Sefton Coast. Photo: © RWD
Swell to almost circular in cross-section, mid-plane. With rounded ridges.


8th Aug 2015, sand dunes, Hightown, Sefton Coast. Photo: © RWD
Some like tiny bananas.


8th Aug 2015, sand dunes, Hightown, Sefton Coast. Photo: © RWD
Shrivelling as they ripen to brown.


8th Aug 2015, sand dunes, Hightown, Sefton Coast. Photo: © RWD
The shape of the leaves as they appear mid-way up the stem.


2nd July 2011, sand dunes, Crosby, Sefton Coast. Photo: © RWD
Lower leaflets with more-rounded teeth but still decidedly asymmetric with wedge-shaped leaflets..


2nd July 2011, sand dunes, Crosby, Sefton Coast. Photo: © RWD
Asymmetric leaflets.


17th June 2014, Crag Foot, Warton, Lancs. Photo: © RWD
The leaves are 2- to 3-pinnate and slightly asymmetrical. Here they are 2-pinnate.


17th June 2014, Crag Foot, Warton, Lancs. Photo: © RWD
The obverse of the leaves showing raised veins.


MEADOW-RUE GALL


(Puccinia recondita)
 Galls and Rusts Menu

8th June 2016, dunes, Hightown, Sefton Coast Photo: © RWD
In the same family (Puccinia) of rusts which infects a number of other plants, including Colt's-foot. Each species of Puccinia is usually specific to one species of plant, this one (Puccinia recondita) commonly infects Common Meadow-rue. Most species of Puccinia look very similar, and usually the species of rust is identified by the species of plant it infects.


8th June 2016, dunes, Hightown, Sefton Coast Photo: © RWD
The rust causes the leaf to turn deep purple around the infection. Your Author is not 100% sure that this rust is the species recondita, but it is definitely a Puccina species, and any rust infection of Common Meadow-rue is reported to be usually caused by Puccinia recondita.


8th June 2016, dunes, Hightown, Sefton Coast Photo: © RWD
Like most other Puccinia rust species, Puccinia recondita is a deep orange-yellow colour and develops mud-volcano-like openings.


8th June 2016, dunes, Hightown, Sefton Coast Photo: © RWD
The 'mud-volcanoes' are called aecia (or 'cluster cups') - a specialised reproductive structure found on some rusts and smuts which produces and releases airbourne spores called aeciospores into the air - by which means it spreads from plant to plant. These rusts are necrophytic obtaining their sustenance from the dead tissues of its host organism. Puccinia recondita also infects Wheat and Rye


It isn't the petals which give the flower the overall appearance of being yellowish cream, but the stamens and anthers; the mostly hidden (or absent, having fallen off) petals are actually white. Hence the colour of the flower is here listed as being yellow and not white.

Lookee-Likees : from afar it is easily mistaken for Meadowsweet because it has a creamy head of fuzziness, but Meadowsweet belongs to the Rose Family. The fuzziness is actually mostly due to dozens of long yellow anthers seemingly sticking out at all angles, but each individual flower only projects them one particular direction and it is the haphazard direction the flowers are facing which gives this impression.

Uniquely identifiable characteristics

Distinguishing Feature :

No relation to : Rue or Goat's-Rue (Galega officinalis) nor Meadowsweet (Filipendula ulmaria) nor to Meadow-Foam (Limnanthes douglasii) or Meadow-grass (Poa bulbosa) [plants with similar names but which belong in differing families]. Nor is it related to Wall-rue (Asplenium ruta-muraria) which is a fern.

Common Meadow-rue inhabits wet meadows, fens or sits beside fresh water. The asymmetrical leaves remind one of Columbine (which is in the same Buttercup Family).

Meadow-rues are poisonous, containing isoquinoline and protoberine alkaloids such as Berberine and also some cynogenic glycosides. Substantial ingestion will cause disturbance of both the gastro-intestinal tract and the central nervous system. It is hypotensive and cytotoxic.

Meadow-rues are taxonomically difficult with poorly understood species boundaries and are in need of further taxonomic research for clarification and possibly re-classification. World-wide there are between 120 to 200 in the genus Thalictrum, in the UK only six or so and two of those are rare.

Both root and leaves yield a very deep-yellow dye used in past times. This is quite possibly the BenzylIsoQuinoline alkaloid called Berberine, which is deep yellow, the same dyeing substance found within the deep-yellow toxic sap of Greater Celandine.

ALKALOIDS

Many IsoQuinoline and particularly BisBenzylIsoQuinoline alkaloids have been isolated from the roots of Common Meadow-rue, such as Thaligosidine, large amounts of Thalfoetidine, NorThalfoetidine, NorThalidasine, and the aporphine PreoCoteine plus quaternary ProtoBerberines such as Berberine, PseudoBerberine and ProtoBerberine. Aporphines such as Preocoteine and MethylCassythine are present. Many of these compounds are potentially anti-parasitic and/or cytotoxic (some more potent than others), they are also toxic to mammals.


ProtoBerberine is an isomer of Berberine, with one of the methoxy (-O-) groups moved. It exhibits anti-amnesic activity, which may be useful for treating memory impairment.

Thalicberine is a BisBenzylIsoQuinoline alkaloid being a near-dimer of two molecules of the BenzylIsoQuinoline alkaloid called Armepavine, with one molecule being slightly altered. There are numerous other slightly differing BisBenzylIsoQuinoline alkaloids to be found within Common Meadow-rue.


Also found is the phenathrene derivative ThaliGlucinone (which is both a lactone and an alkaloid) which exhibits anti-microbacterial activity and is also highly effective against human tuberculosis and leprosy.


  Thalictrum flavum  ⇐ Global Aspect ⇒ Ranunculaceae  

Distribution
 family8Buttercup family8Ranunculaceae

 BSBI maps
genus8Thalictrum
Thalictrum
(Meadow-Rues)

COMMON MEADOW-RUE

Thalictrum flavum

Buttercup Family [Ranunculaceae]

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