POT MARIGOLD

Calendula officinalis

Daisy & Dandelion Family [Asteraceae]

month8may month8jun month8june month8jul month8july month8aug month8sep month8sept month8oct

status
statusZneophyte
 
flower
flower8orange
 
inner
inner8orange
 
morph
morph8actino
 
petals
petalsZMany
 
stem
stem8round
 
smell
smell8faint
faint

24th Aug 2014, Wigan Wallgate rly stn, Lancs. Photo: © RWD
Short to medium height, less than 80cm tall.


24th Aug 2014, Wigan Wallgate rly stn, Lancs. Photo: © RWD
Has brilliant pale-yellow to brilliant orange petals, about 4-7cm across and usually slightly curved downwards. Often double-flowered (flore pleno).


24th Aug 2014, Wigan Wallgate rly stn, Lancs. Photo: © RWD
The centre is a darker shade of orange/brown.


24th Aug 2014, Wigan Wallgate rly stn, Lancs. Photo: © RWD
Petals curving down.


24th Aug 2014, Wigan Wallgate rly stn, Lancs. Photo: © RWD
Has sepal-like bracts called phyllaries around the flower which have bristly hairs.


24th Aug 2014, Wigan Wallgate rly stn, Lancs. Photo: © RWD
The achenes (seeds) are characteristically in-curved and look like green or brownish-purple maggots.


24th Aug 2014, Wigan Wallgate rly stn, Lancs. Photo: © RWD
Several in-curving layers of maggot-like seeds. Dead disc florets still in the centre.


24th Aug 2014, Wigan Wallgate rly stn, Lancs. Photo: © RWD
Phyllaries visibly from above too.


24th Aug 2014, Wigan Wallgate rly stn, Lancs. Photo: © RWD
Both stems and leaves hairy. The leaves are spoon-shaped, and broadest near the top.


PROLIFERATION in POT MARIGOLD

 Mutations Menu
29th March 2012, a garden. Photo: © Dave Symes
Some wild flowers, such as Wild Basil, have tiered flower heads, but they usually belong to the Dead-nettle Family (Lamiaceae) and not to the Dandelion & Daisy Family (Asteraceae) as does Pot Marigold (Calendula arvensis), so tiered flowers are not an un-natural phenomenon. But in the case of Pot Marigold, tiered flowers are certainly not the norm, but they are by no means un-known.

Here the first flower has matured and set seed only to produce a satellite flower from the head, which then sets seed only to produce yet a third satellite. Mutations like these can give clues to the growth process, especially when it goes awry, as here. This is technically called proliferation.



29th March 2012, a garden. Photo: © Dave Symes
The mutation is possibly caused by a viral infection that has probably altered the expression of some aspect of the homeobox genes, which form the basis of the master-plan of growth: where shoots start, where leaves are, the shape and form of the flower-head, things like these. It is an example of Homeosis, where one plant part is mutated into a differing plant part.


Not to be confused with : Bur-marigolds such as Nodding Bur-Marigold (Bidens cernua) or London Bur-Marigold (Bidens connata) or with Corn Marigold (Glebionis segetum) which have similar names and also belong in the same Asteraceae family, but which are all yellow.

Uniquely identifiable characteristics

Distinguishing Feature :

No relation to : Marsh Marigold (Caltha palustris) [a plant with similar name belonging to the Buttercup Family (Ranunculaceae)].

Grown in gardens it is not a plant native to the UK. Occurs as both the single flowered and double-flowered versions and can escape, although whether or not they were planted or thrown out into the wild is debateable, but once there, they do self-seed themselves and spread laterally. An annual that sometimes behaves as a perennial, sometimes over-wintering particularly in the warmer South or West of England, although it cannot tolerate conditions that are too hot.

The petals are edible and are used as a substitute for saffron in cooking rice, making soups or a tea infusion and taste almost of hops. Or used as an edible decoration with rose petals or borage flowers on cakes, salads, desserts or added in the making of cheese or butter. The flower has a faint aromatic smell The leaves too are edible, but not very palatable.

The petals will also yield a dye for fabrics such as wool, cotton, linen, silk and hemp which can be made yellow, orange or brown depending upon the mordant used. The Vikings used it to dye their hair fair. The petals (and pollen) contain the orange/yellow carotenoids Flavoxanthin and Auroxanthin and the clear Lutein (20%).

Both leaves and stems also contain other carotenoids: Zeaxanthin at 5% and Lutein at 80%.

XANTHOPHYLL PIGMENTS


Flavoxanthin is a golden-yellow pigment that is used as food colourant E161a in Australia and New Zealand but is not approved for use in the European Union or USA. (It does not contain the chemical moiety Xanthine which is an alkaloid containing four atoms of nitrogen which is based upon Purine).

The Author can only guess that Auroxanthin, with a larger moiety at each end, will vibrate at a slightly lower frequency and thus absorb light wavelengths with longer wavelengths, putting the reflected light into the orange part of the spectrum.

Note that each have at least one (Auroxanthin has two) epoxy linkages across part of the molecule. This would tend to make them more chemically reactive, therefore probably more deleterious within the human body. Lutein has no epoxy linkages and double-bonds in some slightly differing positions.
Lutein is another Xanthophyll, but one which is colourless (white in powder form).

A FATTY ACID


The oil from the seeds (which are pale-brown, curved and have spines on the back) contains Calendic Acid, a long-chain fatty acid, and is sometimes but rarely extracted commercially as an oil-seed crop for use in protecting the skin.


  Calendula officinalis  ⇐ Global Aspect ⇒ Asteraceae  

Distribution
 family8Daisy & Dandelion family8Asteraceae

 BSBI maps
genus8Calendula
Calendula
(Marigolds)

POT MARIGOLD

Calendula officinalis

Daisy & Dandelion Family [Asteraceae]