DANDELION

PISSABED, DEVIL'S MILK PAIL, HEART FEVER GRASS

Taraxacum officinale

Daisy & Dandelion Family [Asteraceae]  

Flowers: 1 Section Ruderalia
month8Jan month8Feb month8mar month8march month8apr month8april month8May month8jun month8june month8jul month8july month8Aug month8sep month8sept month8Oct month8Nov month8Dec

Flowers: 2 Section Erythrosperma
month8apr month8april month8May month8jun month8june

Pappus: pappusZpossible (all dandelions, white, compound)
pappus8may pappus8jun pappus8june pappus8jul pappus8july pappus8aug pappus8sep pappus8sept pappus8oct

status
statusZnative
 
flower
flower8yellow
 
morph
morph8actino
 
petals
petalsZmany
 
stem
stem8round
 
stem
stem8hollow
hollow
stem
stem8milkysap stem8milkylatex
 

There are 250 different species of Dandelion, belonging to 9 sections, the main two of which are mentioned above. Below are just some of the 250 different Dandelions, many of which only experts can positively identify, so the author is not going to try for he may well get it wrong. He will merely highlight some differences which may, or may not be, significant to identification.

7th May 2003, Fearnley Fields, Chiserley, Hebden Bridge, Yorkshire. Photo: © RWD
A golden sea of Dandelions.


11th May 2008, Peak Forest Canal, Strines, Derbyshire. Photo: © RWD
Flowers and clocks can co-exist. Unlike many flowers belonging to the Dandelion and Daisy Family, Dandelion lacks the central area of disc florets, and consists only of narrow ray florets; hundreds of them.


25th April 2005, Lancaster Canal. Photo: © RWD
Some species have large showy flowers.


1st May 2007, near Strines Reservoir, Sheffield, Yorkshire. Photo: © RWD
This species does not have deeply lobed leaves.


2nd May 2008, Hollingworth Branch canal, Daisy Nook, Manchester. Photo: © RWD
This species does not have lobed leaves.


28th March 2007, St Helens disused canal. Photo: © RWD
Deeply lobed leaves with dark central spine, smaller flowerhead.


28th March 2007, St Helens disused canal. Photo: © RWD
The deep lobes of this species are opposite and not alternate as on the zig-zagged lobes. The central spine is reddish.


2nd May 2008, Hollingworth Branch canal, Daisy Nook, Manchester. Photo: © RWD
Deeply zig-zagged lobes on this species leaves are alternate rather than opposite and are without a dark central spine.


31st March 2008, Harridge Pike, Mossley, Greater Manchester. Photo: © RWD
Deeply lobed leaves with dark central spine.


7th May 2003, Dove Holes, Buxton, Derbyshire. Photo: © RWD
Huge bright yellow-orange flower head. The 'petals' (ray florets) are notched at the tips.


2nd April 2008, Glasson Dock, Lancashire. Photo: © RWD


11th May 2008, Peak Forest Canal, Marple. Photo: © RWD
Opened clock and closed, waisted seed head.


2nd May 2008, Hollingworth Branch Canal, Daisy Nook, Manchester. Photo: © RWD
The closed head of this species is not waisted. Directly under are a number of green bracts, sometimes mistaken for sepals.


11th May 2008, Peak Forest Canal, Marple. Photo: © RWD
Seed clock (pappus) fully opened.


11th May 2008, Peak Forest Canal, Marple. Photo: © RWD
The individual seeds still attached to the Dandelion Flower with their 'parachute' on the end of a long 'stalk'.


29th May 2008, Chinley Churn, Derbyshire. Photo: © RWD
The 'parachutes' (pappus) and seeds (achenes). When mature, the achenes are so lightly attached that the slightest wind above 10mph will set them floating adrift on the wind, to be carried far and set seed.


29th May 2008, Chinley Churn, Derbyshire. Photo: © RWD
The seeds of this species are brown with multiple barbs, which can also get caught in animal fur to be dispersed even further afield.


FASCIATION

 Mutations Menu

Oct 2011, Bury, Lancs. Photo: © Daisy Bailey
This Dandelion looks like it may be fasciated, which is an aberration caused by the flower having an extended (linear rather than spherical) growing centre. It can be caused by one of a number of factors: a bacterial infection, phytoplasmas (which are a recently discovered class of organisms which are evolutionary between bacteria and non-cellular virii), insect or mite attack, chemical (including herbicidal) or mechanical damage, or a mutation in the meristematic cells (these are un-differentiated cells, the equivalent of mammalian stem cells, which then transform themselves, using location and proximity clues, into leaves or stems or flowers). It is likely that fasciation due to insect or mite damage is because they are ferrying pathogems. Some specimens may inherit the trait. It is more common in Dandelions and several other species of plants such as Foxglove, and Willow, but can occur in any plant.


16th May 2012, Hartington, Derbyshire. Photo: © RWD
A fasciated Danelion. The stem here is not twinned, but flat, five times broader than normal in one direction. There are not two flower heads here, only one which has been elongated in one direction.


16th May 2012, Hartington, Derbyshire. Photo: © RWD
A fasciated Danelion. The extended flower head of the above Dandelion.


A DOUBLE-HEADER

Oct 2011, Bury, Lancs. Photo: © Daisy Bailey
A twin-headed Dandelion. Unusual, but not rare. Triple-headed and multiply-headed Dandelions also occur. Here it is the stem which is fasciatated: it is twinned, with a figure-of-eight cross section. Each stem has only one Dandelion flower atop; which is one of the identifying characteristics of Dandelions.


There are more than 240 different Dandelions. They are divided up into 9 sections, which may flower at differing times.

Section Ruderalia with 121 members has large flowers, flowers from January to December, and is the common Dandelion of meadows, waysides and grassy places.

Section Erythrosperma with 30 members flowers from April to June, and are generally the smallest and thinnest Dandelions. Preferring warm dry sunny places the habitat is chalk grassland, heaths and sand dunes.

Section Celtica with 35 members prefers damp meadows.

Section Hamata with 18 members is very weedy. The leaves are hooked at the tip.

Section Naevosa with 12 members preferring the north and western regions. The leaves have many dark splodges.

Section Taraxacum with 6 members prefer mountains and have bright green leaves.

Section Palustria with 4 members have appressed pale-bordered bracts below the flowers.

Section Spectabilia with 3 members prefers damp acidic soils on the hills.

Section Obliqua with 2 members have deep or orange-yellow flowers preferring coastal regions.

Lookee-Likees : A great many other Dandelions, about 250.

Superficial resemblance to: Cat's-ears, Hawkweeds, Hawkbits, Hawksbeards but these usually have branched stems that are both hairy and bear leaves.

Uniquely identifiable characteristics: They all have single un-branched and hollow stems that are leafless and which exude a milky sap or latex on breaking. They are all low, with a basal rosette of long and usually lobed leaves, and the flower head is always yellow or yellowish orange. Dandelion is the only member of the yellow member of the Daisy & Dandelion Family to have a hollow stem.

Between the 250+ odd different varieties of Dandelion, there is always at least one that is in flower at any one time. That is, between them, they flower all year round. But there is a lull around cold winters when no dandelion is in flower. It is very often the during the absence of any dandelions in flower in February and March when you are able to spot the first flowerings of Coltsfoot, which has Dandelion-type flowers, but the petals are much thinner, which otherwise would be hard to spot amongst the myriad of Dandelions. Coltsfoot flowers at least 3 weeks earlier than do Dandelions.

An observation by a friend is that, between them, Dandelions and Daisies seem to take it in turns to smother fields, one year full of Daisys, the next Dandelions. It could be that both rootstocks are present in the ground at the start of the year, and the one which comes to dominate in Spring is dependent upon the particular weather present at the flowers' respective growing weeks. If its warm when Daisies wish to grow or cool when Dandelions wish to grow, then Daisies may win out that year, or vice versa. Whichever dominates first will shade the other into submission. Of course, there may be signalling phyto-chemicals involved too, the one suppressing growth of the other.

Dandelions (as well as Brambles (Rubus, Hawkweeds (Hieracium) all have hundreds of species. They are all apomictic (or agamospermic - asexual reproduction via seeds), capable of the production of viable seeds without self-fertilisation or cross-fertilisation and are entirely female in origin. Plants growing from these seeds are clones. This process results in a wide spectrum of hybrid microspecies, most looking very similar. All or most species of Dandelion are hybrids which reproduce asexually - only a handful reproduce by sexual means. Hawthorns (Cratageous), Rowans & Whitebeams (Sorbus), Meadow-grasses (Poa) and Lady's-mantles (Alchemilla) are also apomictic with dozens of very similar hybrid species.

Although there is only one flower atop each leafless stalk, there can be very many stalks arising from a single basal rosette of leaves. Cunningly, they don't all rise at once, but keep a low profile amidst the grass and take turns at growing, especially just after mowing, such that there is always one stalk ready to set seed when the gardener has been away for just a day!

No one has ever seen a dandelion where half of the flower is yellow petals and the other half a seed clock. So secret and sudden is the metamorphosis from flower to seed that some people think that they are two different plants! One day the flower closes up for the night one last time, enshrouded by its sepals, and in the morning miraculously opens up as a seed clock.

The roots can be dried, ground and roasted to make a caffeine-free coffee substitute, sold as Dandelion Coffee by various health stores.

A very interesting drink can be made with Dandelion and Burdock sold as 'Dandelion & Burdock' by the only remaining Temperance Bar in England, who reside in Rawtenstall, Lancashire. It seems to be illegal to make Dandelion and Burdock at home, this being possibly due to the hepatotoxic Pyrrolizidine alkaloids present in Burdock which the brewer may un-wittingly incorporate into the brew.

The nick-name pissabed is due to the diuretic effect after drinking potions.

A close relative of Dandelion, Russian Dandelion (Taraxacum kok-saghyz) aka Rubber Root, which is a yellow dandelion not native to the UK, used to be harvested during the second World War for the milky latex it produces, which can be used as a substitute for rubber latex. But as the milky latex seeps out from the stems, it is quick to polymerize into a much more viscous substance, so it had to be used quickly. It has now been genetically modified so that the enzyme responsible for the rapid polymerisation is switched off, and it now produces up to five times more latex. The latex is hoped to be used to replace rubber latex from trees, which are succumbing to a fungal infection in many parts of the world where rubber trees are harvested for their latex. The plant also produces a diabetic-safe sugar called Inulin which can also be harvested.

Dandelion contains the allergen Taraxinic Acid, another Sesquiterpene Lactone, which may have application in the treatment of leukaemia. Dandelions have been known to cause allergic reactions and contact dermatitis due to this toxic component.

Tetrahydroidentin B is another sesquiterpene lactone found in Dandelions, and is a plant secondary metabolite.


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Taraxacum
(Dandelions)

DANDELION

PISSABED, DEVIL'S MILK PAIL, HEART FEVER GRASS

Taraxacum officinale

Daisy & Dandelion Family [Asteraceae]  

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