REVERSED CLOVER

PERSIAN CLOVER

Trifolium resupinatum

Pea Family [Fabaceae]

month8jun month8june month8jul month8july month8aug month8sep month8sept

status
statusZneophyte
flower
flower8pink
flower
flower8lilac
inner
inner8white
morph
morph8zygo
petals
petalsZ5
type
typeZclustered
stem
stem8round
stem
stem8ribbed

28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
Sprawling with long thick stems amongst the other vegetation near the side of an arable field. It is usually planted as a nitrogen fixer for the soil, but this was the only specimen your Author saw. It is maybe last years sowing which has sprung up again(?). Only the flowerheads were previously on the surface until your Author gently raised them out of the thick vegetation to see what's what. [The field opposite had been planted with acres of Crimson Clover for a similar reason].


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
The stems are thick and the undersides of this clover flowerhead looked oddly different to all other clovers your Author has seen. [There's a reason for this...]


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
From above the flowerheads of this clover look strangely flatter than other clovers.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
From above it looks as though each flower has maybe 6 leaves around it, when leaves on other clovers are in threes. But they are in 3's here too! It's just that from above the leaves look like they are in 6's (or sometimes 9's).


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
The leaves are oval(ish), often have long(ish) teeth (in comparison to other clovers) but they are still in 3's. The flowerheads are flatter than the usually domed outline of other clovers. [the leaves here have been eaten by an insect]. The main stems are thick, very long and often ribbed. The flowerheads are on longish petioles (stalks) with only a few branching off near the end.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
These leaves have been nibbled less by insects. Leaf teeth longish, pointed, forwardly directed. Viewed by transmitted light the leaflet veins are paler and often end at a tooth. There are two sets of trefoil leaves in close proximity, giving the impression from above that there are 6 leaves around each. At each branch from the main stem are a broad pair of darkly-striped bracts (at least when viewed from below). Viewed from below the flowerheads have a flattish conical base which has a pale central annulus and dark-green teeth.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
Only when the flowerhead is inspected close up from above do the above anomalous facts become clearer: each pea-type floret is upside down! to what is normal in other clovers: The banners here are below the wings and the keel petals! [The flowerhead at top right is still unfurling].


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
It is the longer banners of the florets which are splayed out around the circumference which makes it appear flatter than other clovers. [The inner florets are still the wrong way around but more upright (banner towards the outside; wings and keel towards the centre of the flowerhead).


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
The large banner petals are facing the outside whilst the smaller wings and keel petals are facing towards the centre of the flowerhead.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
In the centre are the sepal teeth of the inner florets.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
The banners, wings and keel are plainly visible in the floret directed towards the bottom left corner.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
The banners of the inner florets are still wrapped up in rolled-newspaper fashion here, hiding the wings and keel.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
In a flattened conical shape below the flowerhead are the sepal cups with their teeth. Because the flowers are upside-down in comparison to other clovers, so too are the sepal cups.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
The cup parts of the sepals are nearly white whereas the sepal teeth are dark green. It is the 3 shortest teeth (dark green) which are showing on the underside of the flowerhead (whilst the 2 longer sepal teeth are on the other side of the florets helping to direct the banners of the outer florets outwards). This is the 'florets upside down' meaning of Reversed Clover.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
These two flowerheads have yet to fully open, the lower one being at a less advanced stage than the half-open upper flowerhead. Here the sepal teeth of each sepal cup can be seen simultaneously, unobscured by the still to emerge florets. Note the square petioles (flower stalks).


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
A closer view of a still developing flowerhead with the florets yet to emerge from their sepal cups. The outer 3 teeth are shorter than the inner two.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
3 sets of trefoil leaves.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
The leaves have forwardly-directed sawtooth teeth, the points of which correspond to the edge termination of the leaf veins (which is why they are forwardly directed - because the veins are directed at c. 45° outwards from the main central vein which is where the leaf is folded).


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
At each side of a branch from the main stem are a pair of broad darkly-striped bracts (at least when viewed from below).


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
At each side of a branch from the main stem are a pair of broad darkly-striped bracts (at least when viewed from below). Leaf teeth at every vein termination.


28th Sept 2018, arable field, Gaw Hill, nr. Ormskirk, Lancs. Photo: © RWD
The main stems are either grooved or more usually ribbed (there are at least 4 main stems visible here).


Uniquely identifiable characteristics

Distinguishing Feature : Compared to (all?) other clovers, this one has the florets 'upside-down' - with the banners facing outwards (and the wings and keel facing towards the centre)

Reversed Clover is in the same sub-family of Trifolium as is Strawberry Clover (Trifolium fragiferum) - that of Vesicaria but the flowers of Reversed Clover are upside down unlike those of Strawberry Clover where they are the normal way around. The two look totally different from each other except when both are in the fruiting stages where the fruits of both are bent over downwards, but those of Strawberry Clover are reddish brown whereas those of Reversed Clover a fawny brown.

It is a casual neophyte growing randomly. It is also fairly widely planted as seeds in the margins of arable fields, which is the exact place your Author found it. There it acts as a sown nectar mix and a green manure, supplying extra nitrogen to the soil which the plant has harvested by the aid ot nitrogen fixing symbiotic organisms from the air. There is then no need to apply expensive nitrogen fertilisers.

There is a similar, but smaller flowered Clover in the same Vesicaria section as both this and Strawberry Clover called Woolly Clover (Trifolium tomentosum) which is very hairy and with the calyx teeth being completely or almost completely obscured but the flowrs are smaller (3 to 6mm (as opposed to the 5 to 7mm of Reversed Clover) and which is much more procumbent than is Reversed Clover with stems half the length (at 15cm long) as that of Reversed Clover at 30cm.


  Trifolium resupinatum  ⇐ Global Aspect ⇒ Fabaceae  

Distribution
 family8Pea family8Fabaceae

 BSBI maps
genus8Trifolium
Trifolium
(Clovers)

REVERSED CLOVER

PERSIAN CLOVER

Trifolium resupinatum

Pea Family [Fabaceae]