FOUR-LEAVED ALLSEED

Polycarpon tetraphyllum

Carnation & Campion (Pink) Family [Caryophyllaceae]

month8apr month8april month8may month8jun month8june month8jul month8july month8aug month8sep month8sept month8oct month8nov month8dec

status
statusZnative
 
flower
flower8white
 
inner
inner8green
 
morph
morph8actino
 
petals
petalsZ5
 
type
typeZclustered
 
stem
stem8round
 
stem
stem8ribbed
 

rarity
rarityZscarce
(var. diphyllum & tetraphyllum)

12th Aug 2013, Photo: © Bastiaan Brak
A rather rare and casual plant growing in cracks and waste ground near the sea on bare sandy soils with branched stems to 25cm long.


12th Aug 2013, Photo: © Bastiaan Brak
Does not reach very high at all, being mostly sprawling and prostrate.


12th Aug 2013, Photo: © Bastiaan Brak
Has leaves which grow in whorls of 4 (as in the centre), but they don't seem as numerous are the leaves growing in opposite pairs (lower left corner).


12th Aug 2013, Photo: © Bastiaan Brak
Some leaves larger than others and shaped like spoons with flattened stems. Main stems are slightly ribbed (near centre).


12th Aug 2013, Photo: © Bastiaan Brak
The flowers have already mostly flowered and are now turning to seed. The four sepals are green with a white margin around the edges.


12th Aug 2013, Photo: © Bastiaan Brak
The yellowish-orange fruits can just be made out within the sepals of several flowers.


12th Aug 2013, Photo: © Bastiaan Brak
The stems are well-branched.
[The juxtaposition of oranges, white and and green stripes in this image initiates thoughts of some long-forgotten toffees from his bygone youth. Maybe the delicious black Spangles in orange and white striped wax-coated wrappers?]


12th Aug 2013, Photo: © Bastiaan Brak
Each stem junction has a papery sheath around it. The sepals are turning yellowish-green to orange-red. A fruit can be espied protruding on the orange flower (far-left, half-way up). That flower also shows the sepals which are all keeled into a V-shape.


12th Aug 2013, Photo: © Bastiaan Brak
The white bits visible are the white margins of the sepals rather than the shorter white petals.


15th Feb 2018, Sheffield Botanical Gardens, Yorks. Photo: © RWD
By comparison this is a trampled and battered specimen barely 5cm across all-in.


15th Feb 2018, Sheffield Botanical Gardens, Yorks. Photo: © RWD
White sheaths around each stem junction.


15th Feb 2018, Sheffield Botanical Gardens, Yorks. Photo: © RWD
The leaves are either in whorls of 4, or in opposite pairs. The nodes near the roots are bulbous.


15th Feb 2018, Sheffield Botanical Gardens, Yorks. Photo: © RWD
Leaves very variable, some narrow spoon-shaped, or lanceolate without stalks.


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
Whilst other leaves are oval or rhombohedral.


15th Feb 2018, Sheffield Botanical Gardens, Yorks. Photo: © RWD
Whilst other leaves are wide-spoon-shaped with flat stalks. The straggly paper-thin white objects may be more sheaths rather than petals (it hasn't flowered properly yet). They are certainly not petals (which are shorter than these and not finely tapered but instead rectangular)


15th Feb 2018, Sheffield Botanical Gardens, Yorks. Photo: © RWD
The keeled form of the 4 sepals can be clearly espied here.


15th Feb 2018, Sheffield Botanical Gardens, Yorks. Photo: © RWD
The sepals appear elongated on as-yet unripe flowers.


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
A flowering specimen.


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
The leaves and/or bracts are of disparate sizes and shapes.


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
The flowers are tiny.


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
Flowers still to open on this part of the plant. Oh, look, the topmost stems are square or angular, with two emerging telescopically from a lower thicker part of the stem, this with two long, membranous, white sheaths.


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
Flowers within nominally 4 curved V-shaped cross-section sepals. Petals white, long-oval with a tiny nick at the end (top, centre, visible only with a hand-lens)


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
There are usually 5 petals, which are nearly rectangular with a slight widening near the centre, some with a tiny notch at the apex. There are between 3-5 stamens (with bright-yellow pollen) but only 3 tiny stigmas. Many sepals, besides having an acuminate point at the tip, are also hooded just below the tip, as well as fringed by a translucent-white membrane.


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
Sepals at the top have thin translucent-white membranous sheaths on the edges of the sepal (which do not reach the acuminate point at the tip of the sepals).


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
The inner side of the pointed sepals is coated with a thin translucent white veil which extends slightly beyond the width of the sepal and also has a propensity to peel off as the sepal grows. These are not the white acuminately-pointed membranous tissues which are seen extending from those specimens at Sheffield Botanical Gardens; for those are the pointed white sheaths around new flower buds.


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
The petals are seen to be constructed from translucent white very elongated cells (best seen in top-right petal) whereas the membranous white sheaths half welded to the inner surface of the green sepals is constructed from long but much wider cells (best seen in lower right sepal). The style is very short and atop it are 3 short, tiny, triangular stigmas barely visible atop the large greenish-white nearly-spherical central ovary. The 3-5 (3 here) stamens are topped by anthers with deep-yellow pollen grains (some of which are scattered about the flower). The inner part of the 5 white petals are also greenish-yellow.


11th May 2014, a garden, Yolo, California, USA. Photo: © Robert F. Norris
The 4 canoe-shaped sepals with their white membranous edges and their translucent acuminate tips. Any hairs are truly microscopic and sparse.


Not to be semantically confused with : Allspice (Pimenta dioica) [Allspice is also a generic word for quite a few differing spices too, none of them native to the UK, not even the one quoted]. Nor with Allseed (Radiola linoides) which is another small native plant only 6cm long with opposite leaves, with 4 petals, 4 sepals and 4 stamens which grows on open acidic damp damp ground either peaty or sandy and near the coast.

Easily mistaken for : Annual Knawall (Scleranthus annuus) but that is petal-less with five sepals and narrow and linear leaves in opposite pairs only which are fused at the base

Some similarities to : Common Mouse-ear (Cerastium fontanum) and other Mouse-ears.

No relation to : Oil-Seed Rape (Brassica napus ssp. oleifera) [plants with similar names belonging to differing families].

The flowers are said to be Homogamous (which simply means that both male and female organs of the plant mature at the same time), self-pollinated and often Cleistogamous.

They have 5 white, narrow membranous petals which sit between the broad, green cupped sepals with white edges, with between 3 to 5 stamens with cream-coloured pollen. There are 3 separate styles each with a single stigma. The flowers only rarely seem to open and even when they do, only at a subtended angle of about 90°. The fruit is a longer than wide capsule which opens by 3 valves.

There is a variety called Polycarpon tetraphyllum var. diphyllum which has only 1-3 stamens (rather than 3-5), and leaves that are only in opposite pairs (rather than a mixture of whorls of 4 and opposite pairs). These also have shut inflorescences (like in 2 of the sets of photos above (but both those specimens also have leaves in whorls of 4 as well as in opposite pairs - so the above photos cannot be of this variation, despite no flowers being open in either set).


  Polycarpon tetraphyllum  ⇐ Global Aspect ⇒ Caryophyllaceae  

Distribution
 family8Carnation & Campion (Pink) family8Caryophyllaceae

 BSBI maps
genus8Polycarpon
Polycarpon
(Four-Leaved Allseed)

FOUR-LEAVED ALLSEED

Polycarpon tetraphyllum

Carnation & Campion (Pink) Family [Caryophyllaceae]