GREAT MULLEIN

COMMON MULLEIN

Verbascum thapsus

Figwort Family [Scrophulariaceae]

month8jun month8june month8jul month8july month8aug

status
statusZnative
flower
flower8yellow
inner
inner8orange
morph
morph8hemizygo
petals
petalsZ5
type
typeZspiked
stem
stem8round

9th July 2008, near Gait Barrows, Lancs. Photo: © RWD
A single-stemmed tall handsome plant to 2m tall. Large lanceolate leaves with prominent veins on underside, all pointing upwards close to the stem.


14th July 2007, Bridgewater Canal, Manchester. Photo: © RWD
Covered in short white woolly hairs all over, flowers all clustered together in top third of the stem.


30th June 2008, River Lune, Lancs. Photo: © RWD
Mid-yellow flowers with five rounded petals, bottom ones slightly larger than those at the top.


30th June 2008, River Lune, Lancs. Photo: © RWD
Five stamens inside, the top three covered in white hairs, the bottom two hairless. [If all five have hairs then it might be Hoary Mullein].


11th July 2005, Cumbria Coastal Path. Photo: © RWD
The petals have short hairs as well.


9th July 2005, Hayfield, Derbyshire. Photo: © RWD
The five anthers are orange. The stigma green at first.


9th July 2005, Hayfield, Derbyshire. Photo: © RWD
Five stamens, only upper three of which are hairy in Great Mullein. Pollen scattered on inner side of petals.


14th July 2007, Grange over Sands. Photo: © RWD
The leaves mealy, and covered in white hairs all over.


30th June 2008, River Lune, Lancs. Photo: © RWD
Light (Kendal Green) Mealy leaves.


30th June 2008, River Lune, Lancs. Photo: © RWD
Leaves covered in short white hairs both sides.


11th July 2005, Grange over Sands. Photo: © RWD
A garden variety. Here the hoary leaves are shedding the white hairs (Great Mullein does not exhibit this). Although Great Mullein can have multiple flowering stalks near the top, as shown here, it most commonly does not. This specimen may be the garden hybrid between Great Mullein and Hoary Mullein called Vebascum × godronii.


Easily confused with : Hoary Mullein [but although that initially has white hairs on the leaves, they are easily shed. Also, Hoary Mullein is candelabra-branched, similar to the last photograph.]

Hybridises with :

  • Hungarian Mullein (Verbascum speciosum) [which has a branched main stem with flowers on all branches] to produce Verbascum × duernsteinense, which occurs in Cambridgeshire and Norfolk.
  • Hoary Mullein (Verbascum pulverulentum) to produce Vebascum × godronii which occurs in Norfolk and may also be a garden escapee. This hybrid sheds the white hairs in patches to leave the leaves semi-shiny.
  • White Mullein (Verbascum lychnitis) to produce Vebascum × thapsi which occurs with its parents in south and central Britain.
but both parents generally need to be present in the area for this to occur with Mulleins, and the hybrids are usually (but not always) sterile and cannot reproduce. Hybrids between the white-flowered White Mullein (Verbascum lychnitis) and any yellow flowered species are yellow. Hybrids between any species with two obliquely positioned anthers and those with straight anthers may not result in flowers with any obliquely positioned anthers.

Uniquely identifiable characteristics

Distinguishing Feature :

ROTENONE

Rotenone is found in the roots of Great Mullein, as well as in several other plants including Goat's Rue, and in several non-native plants. It is a strong natural pesticide and insecticide that is used commercially as such, sometimes under the generic name Derris Powder which took its name from the non-native plant Tuba Plant (Derris elliptica) from which it was derived. It is a solid, obtained in powder form but used dissolved in water. It is also extremely toxic to fish when dissolved in water because it is absorbed directly into their blood stream via their gills, and is thus sometimes used as a piscicide; the fish float dead on the surface almost immediately. It was utilised this way by various indigenous tribes. Rotenone exerts its toxicity by interfering with electron transport in Mitochondria, the organelle within every cell of mammalian bodies and which is responsible for generating an energy supply for the cell in the form of Adenosine Triphosphate.

It is relatively safe for humans and mammals because it is very poorly absorbed by the gastro-intestinal tract, but care should be taken for it has been linked to Parkinson's Disease. Deliberate ingestion can be fatal. Although its lifetime when exposed to sunlight is relatively short at less than a week, in water it can survive for 6 months, and its use near water courses is highly discouraged.


There are also a number of Triterpene Saponins in Mullein such as Verbascosaponin, compare Cyclamin which also has an oxygen bridge on the steroidal component. The glycoside units are shown in blue.

Also several Iridoid Glycosides such as Aucubin and Catalpol plus related compounds, and a few flavonoids which amount to 4% such as Rutin and Hesperidin. Hesperidin is found mainly in the skins of citrus fruits. It is a flavonone glycoside; the non-glycosidal component being the flavonone Hesperitin. Hesperidin is thought to contribute to the defence of the plant against pathogenic attack. It also acts as an anti-oxidant and can apparently cross the blood-brain barrier.


  Verbascum thapsus  ⇐ Global Aspect ⇒ Scrophulariaceae  

Distribution
 family8Figwort family8Scrophulariaceae

 BSBI maps
genus8Verbascum
Verbascum
(Mulleins)

GREAT MULLEIN

COMMON MULLEIN

Verbascum thapsus

Figwort Family [Scrophulariaceae]

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