COMMON MILKWORT

Polygala vulgaris

Milkwort Family [Polygalaceae]

month8may month8jun month8june month8jul month8july month8aug month8sep month8sept

status
statusZnative
 
flower
flower8blue
or >
flower
flower8mauve
or >
flower
flower8pink
or >
flower
flower8white
 
inner
inner8white
 

morph
morph8zygo
 
petals
petalsZ3
looks-like 5
type
typeZspiked
 
stem
stem8round
 
stem
stem8square
 
stem
stem8ribbed
 
sex
sexZbisexual
 

22nd May 2015, Hightown, Sefton Coast. Photo: © RWD
Common Milkwort is the commonest milkwort and can be either procumbent or erect or even scrambling.
The leaves do not form a basal rosette (as they do in Dwarf Milkwort). Chalk Milkwort produces an irregular false rosette of blunter leaves at the base).


22nd May 2015, Hightown, Sefton Coast. Photo: © RWD
Its leaves are all alternate on the stem.


22nd May 2015, Hightown, Sefton Coast. Photo: © RWD
It can branch and grows up to 30cm long and usually has more than 10 flowers in its main stalk (side-branches may have fewer). [Whereas Heath Milkwort usually has less than 10 flowers - but on Heath Milkwort, they can drop off leaving just the stump on the stem].

Your author did question the apparent rosette of leaves on one of these specimens (top centre) but was reliably informed that this was Common Milkwort (rather than Chalk Milkwort [which grows only near the South Coast] or the [RRR] rare Dwarf Milkwort which grows in Kent, some parts of Yorkshire, County Durham and Westmorland].



12th June 2008, Cressbrookdale, White Peaks. Photo: © RWD
Its flowers can be shades of blue, purple, pink or white (as can those of Heath Milkwort). Here blue. Common Milkwort has and well-branched anastomosing veins [which other milkworts lack (apart from the slight chance that Chalk Milkwort occasionally may have sparingly anastomosing veins)].
Anastomosing means that the veins get more numerous towards the edge and moreover often curl back and intercept each other making an increasingly denser network the nearer the edge (see petals near the centre).


12th June 2008, Cressbrookdale, White Peaks. Photo: © RWD
The anastomosing veins solely of Common Milkwort are also plainly visible here, especially in the lowest two unopened blue flowers.
The lowest 3 flowers have dropped their calyx sepals (which have mostly lost their blue coloration) to envelop the developing two ovaries hidden within.


12th June 2008, Cressbrookdale, White Peaks. Photo: © RWD
A blue specimen showing the fringed parts just below the central petal.


12th June 2008, Cressbrookdale, White Peaks. Photo: © RWD
Just by chance this specimen has 3 flowers near the top which are fully open. Each has 3 blue petals, two large oval ones flanking a central one. There are two much shorter sepals, both long and narrow, but only the one at the top partially covering the central petal can be seen from the top. (All best seen in the flower at the bottom). There is a profusion of as-yet un-opened, much smaller flower buds in the centre.


12th June 2008, Cressbrookdale, White Peaks. Photo: © RWD
A flower has 3 blue petals, two large oval ones flanking a central one. There are three outer sepals (perhaps wrongly assumed to be extra petals), all three long and narrow, but here only the one at the top partially covering the central petal can be seen from the top. The two other out of the total of 5 sepals are inner sepals, unseen normally(?).


28th May 2012, Great Orme, Llandudno, N. Wales. Photo: © RWD
Both Common Milkwort and Heath Milkwort have stem leaves which get smaller down the stem. [Whereas the leaves on both Chalk Milkwort and the very rare Dwarf Milkwort get larger lower down]


28th May 2012, Great Orme, Llandudno, N. Wales. Photo: © RWD
The flowers can be shades of blue, purple, pink or white (as can those of Heath Milkwort). Here purple.
This specimen is revealing the (here greenish-purple) bulge just below the (here pale mauve) fringe of bifurcated linear lobes (top left of photo) which are at the end of the narrow third (central) petal. The linear lobes are the terminal part of that central petal. [Hiding behind the central petal here are the usually unseen (as they are here) two sets of white, 4-fingered filaments/stamens projecting out from the end of a flat object, or which there are two which are joined together further down].
All in all, Milkworts are unique, and have certain features not represented on any other species of flower!


28th May 2012, Great Orme, Llandudno, N. Wales. Photo: © RWD
The two outer petals lose their colour, reverting to green (albeit pale green) and close up once again around the central flower whilst it goes to fruit.


28th May 2012, Great Orme, Llandudno, N. Wales. Photo: © RWD
At the top is another flower with 3 petals, 2 large either side of a narrower but longer top petal under which the male and female parts are hidden.


30th May 2009, nr. Freshfields, Sefton Coast. Photo: © RWD
A pink specimen.


30th May 2009, nr. Freshfields, Sefton Coast. Photo: © RWD
Pink ones displaying their paired, multiply cut part of the end of the central petal.


26th April 2011, Sliabh, Coilte, Campile, Co. Wexford Photo: © Paula O'Meara
An almost white specimen with pale blue 'wing' petals. The 3 outer sepals are here green with a white border (you can't see more than 2 at a time on these flowers); your Author doesn't seem able to locate the 2 inner sepals [he didn't realise how unusual or intricate Milkwort flowers were when he came across them].


7th May 2008, Brading Down, IOW. Photo: (CC by 2.0) Geoff Toone
A lilac specimen.


28th May 2012, Great Orme, Llandudno, N. Wales. Photo: © RWD
A mauve specimen.


28th May 2012, Great Orme, Llandudno, N. Wales. Photo: © RWD
A side-view of the central petal showing how it goes over the cut ends of part of that petal. The outer two petals are in foreground and background.


26th May 2015, Millers Dale, White Peaks. Photo: © RWD
A branched specimen (they often branch).
The leaves get shorter towards the base, and more crowded but still alternate, but that may be harder to discern especially on this still-growing specimen. This specimen seems to have a large anomalously oval leaf a bit below all the other leaves - your Author can find no other drawing or photo on the web with a specimen with this feature. A puzzlement!


26th May 2015, Millers Dale, White Peaks. Photo: © RWD
The shorter outer sepals are still green (turning pink) on this side. The inner sepals are are the next layer of sepals, pink and much longer than the outer sepals. These inner sepals have veins which loop back on each other, getting more numerous but smaller the closer to the edge [best seen in lower right flower]


26th May 2015, Millers Dale, White Peaks. Photo: © RWD
The flip side of the photo above this one playing a slightly different tune.


26th May 2015, Millers Dale, White Peaks. Photo: © RWD
The anastomosing veins on the larger inner paired sepals.


26th May 2015, Millers Dale, White Peaks. Photo: © RWD
The linear leaves get shorter lower down on Common Milkwort, but they are all alternate, despite the crowding on this yougish specimen.


Photo: © Paula O'Meara
Some specimens can be white, as here. This one may have 29(?) (or more) flowers on it.
[This photo has been upended to show it in more detail; it should really be horizontal].


Hybridizes with :

  • Chalk Milkwort (Polygala calcarea) to produce Polygala vulgaris × calcarea × forming either sterile triploids or fertile tetraploids which are found scattered in South Eastern England.
  • Dwarf Milkwort (Polygala amarella) to produce Polygala vulgaris × Polygala amarella which was once found in East Kent amidst both parents in the early 1970's and has large lower leaves which possess an astringent taste (as do the leaves of Dwarf Milkwort. This once-seen (by experts, not your Author) hybrid exhibits far more vigorous growth than Dwarf Milkwort). Good luck finding another specimen!
No relation to : Sea Milkwort (Glaux maritima), Milk Thistle (Silybum marianum), Purple Milk Vetch (Astragalus danicus), Lesser Milk-vetch (Astragalus odoratus), Alpine Milk-vetch (Astragalus alpinus), Milky Bellflower (Campanula lactiflora), Milk-parsley (Thyselium palustre), Cambridge Milk-parsley (Selinum carvifolia) [plants with similar names belonging to differing families].

Many similarities to : other Milkworts (Polygala species)


  • DISTINGUISHING BETWEEN COMMON MILKWORT
    AND HEATH, CHALK AND DWARF MILKWORTS
  • LENGTH OF PLANTS: Common Milkwort up to 30cm, erect or scrambling. Heath Milkwort up to 25cm scrambling to procumbent. Chalk Milkwort erect to ascending to 20cm. Dwarf Milkwort erect to ascending up to 10cm [16cm occasionally].
  • LEAF ARRANGEMENT: Common Milkwort has leaves which are all alternate on the stem and do not form a basal rosette (as they do in Dwarf Milkwort). Chalk Milkwort produces an irregular false rosette of blunter leaves near the base (but stem bade leafless).
  • LEAF SIZE DISTRIBUTION: Both Common Milkwort and Heath Milkwort have stem leaves which get smaller down the stem. [Whereas the leaves on both Chalk Milkwort and the very rare Dwarf Milkwort get larger lower down]
  • NUMBER OF FLOWERS: Common Milkwort usually has more than 10 flowers (10 to 40 per spike) in its main stalk (any side branches may have fewer). [Whereas Heath Milkwort usually has less than 10 flowers (3 to 10) - but on Heath Milkwort, they can drop off leaving just the stump on the stem]. Chalk Milkwort has 6 to 20 per spike. Dwarf Milkwort 7 to 30 on main spike.
  • COLOUR OF FLOWERS: The flowers of Common Milkwort can be shades of blue, purple, pink or white (as can those of Heath Milkwort). [The flowers of Chalk Milkwort are usually gentian blue and only rarely are they pink or white. The flowers of Dwarf Milkwort vary depending upon location: in the North they are blue or pink but in the South they are blue or greyish-white.]
  • SIZE OF FLOWERS: Common Milkwort 4 to 7mm. Heath Milkwort 4.5 to 6mm. Chalk Milkwort 3 to 6mm. Dwarf Milkwort 2 to 5.5mm.
  • VEINS ON PETALS: Common Milkwort has well-branched anastomising veins [which other milkworts lack (apart from the slight chance that Chalk Milkwortt occasionally may have sparingly anastomosing veins)]. Anastomosing means that the veins get more numerous towards the edge and moreover often curl back and intercept each other making an increasingly denser network the nearer the edge (see petals near the centre)
  • HABITAT: Common Milkwort chalk or limey or acidic grassland, heathland and sand dunes. Heath Milkwort acid grassland or heathland. Chalk Milkwort and Dwarf Milkwort chalk or limestone grassland.
  • RARITY: Common Milkwort and Heath Milkwort fairly common. Chalk Milkwort a slightly rare [R]. Dwarf Milkwort a very rare [RRR]

It is native and occurs frequently throughout Britain on calcareous or acid grassland or heath or sand-dunes.


  Polygala vulgaris  ⇐ Global Aspect ⇒ Polygalaceae  

Distribution
 family8Milkwort family8Polygalaceae
 BSBI maps
genus8Polygala
Polygala
(Milkworts)

COMMON MILKWORT

Polygala vulgaris

Milkwort Family [Polygalaceae]