LARGE-LEAVED AVENS

Geum macrophyllum

Rose Family [Rosaceae]

month8apr month8april month8may month8jun month8june month8jul month8july

status
statusZneophyte
flower
flower8yellow
inner
inner8green
morph
morph8actino
petals
petalsZ5
stem
stem8round
sex
sexZbisexual

10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
In appearance, very close to Wood Avens but the ripe seed heads are not globular but elongated.


8th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
Blazenly out in the open with nothing for protection from the sun all day, unlike Wood Avens which prefers semi-shade on wide paths through woods. This seems to be atypical behaviour though, mostly it grows alongside paths in woods just like Wood Avens does.


8th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
Whereas Wood Avens grows to 70cm, Large-leaved Avens grows to 1m high - but its not that high here.


8th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
These are the elongated seed heads - and your Author thinks it might just have more flowers aka seed heads than does Wood Avens, but don't count on it...


8th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
The flowers are mostly turned to seed heads; only one (or two?) remain (top centre) in this photo.


10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
Ripe seed heads elongated into ellipsoidal shape, some with a flat bottom (rather than globular as in Wood Avens)


10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
Flowers yellow with 5 petals, very much like those of Wood Avens but can be slightly smaller.


10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
Five yellow petals and a ring of yellow anthers.


10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
Numerous green styles occupy and dome out from the centre surrounded by the ring of yellow anthers [a bug top centre for scale]. Later the styles will turn from green to yellow as they dome out further - and eventually into a domed fruit with the styles on the ends of much longer red projections from the growing green (at first) seed capsules.

An as-yet green and unopened flower lurks between the two petals top right, its sepals still closed at the top.



10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
This specimen highly symmetrical bearing 7 flowers/seed heads at the top (there may well be more flowers on lower branches).


10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
The rightmost flower has turned to seed (the green things in the centre) surrounded by long, thin red extensions of the seeds with a double-king leading to the much shorter yellow style. The yellow style will later drop off leaving just the green seeds in the centre and the red extensions with a hooked tip.

The leftmost flower has shed its 5 yellow petals but has not yet turned to seed (it may not have been fertilised yet - or it might have opened later than the other). There are two longish ligules at the stem junction.



10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
This short section is bearing 5 flowers in varying stages of progression; two not yet opened with their sepals tightly shut.


10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
When flowering or fruiting the sepals are strongly reflexed downwards.


10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
The yellow styles are still attached via a double-kink to the red extension of the green (at first) seed capsules.


8th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
The kinked yellow styles have dropped off now leaving the flattish green seed capsules and their attendant long red extensions with a short hook on the end - which awaits hooking onto animals fur (or human clothing) in order to transport the seed elsewhere to perchance grow into another plant.


10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
A flower which has lost its 5 petals but still has its outer ring of yellow filaments, some with their now brownish anthers attached. The much more numerous styles should be doming out much more from the centre but maybe this is a failed flower?




DIFFERENTIATING between LONG-LEAVED AVENS and WOOD AVENS

10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
The ligules (a pair of flaps just below and on the side of each leaf) of Large-leaved Avens are longer at 6 to 15mm (whereas on Wood Avens they are shorter at 3 to 6mm long)


10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
The receptacles (that is the saucer-shaped bulge beneath the sepals, and usually hidden by the sepals which are reflexed downwards during and after flowering) of Large-leaved Avens are sparsely hairy with only short hairs (whereas on Wood Avens they are densely hairy with long hairs)


10th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
Also, another difference - your Author does not think the styles at the ends of the long red hook of the seed are ever yellow on Wood Avens - certainly he has never seen yellow ones on all the Wood Avens which pop up in his garden, having been introduced to it from elsewhere by his cats.


8th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
But they dont stay yellow forever; before dropping off altogether they go red. The achenes (seeds plus their long, hooked appendage) of Large-leaved Avens are usually in an elliptic-oblong head when mature (whereas on Wood Avens they are in a globed head)


8th July 2019, boating lake, Etherow Country Park, Crompton, Marple. Photo: © RWD
The petals of Large-leaved Avens can be smaller (at 3.5 to 7mm long) (whereas those of Wood Avens can be slightly larger at 4mm to 7mm long [up to 10mm long] but there is a large overlap in size so unless a large number of the flowers' petals are measured the results could be inconclusive).

Further Notes on ID:

Clive Stace does not go into the size of the leaves even though that appears to be the reason for both the common name of this Avens ('large leaved') and the specific epithet ('macrophyllum') - so apparently the size of the leaves is not reliable as a means to differentiate between the two.

Your Author also thinks that the unusual location of this avens (in the open and away from any shade from the sun) and right next to water are also clues as to these avens being unlike Wood Avens which seem to prefer at least some shade from the sun as it arcs across the sky - [not to mention the 'woods' part of the name]. From the waterside aspect of these specimens - perhaps they are more like Water Avens - but the flowers are not at all like those of Water Avens and much more like Wood Avens.


Easily mistaken for : Wood Avens (Geum urbanum) - see text

Hybridizes with :

  • Wood Avens (Geum urbanum) to produce Geum × convalis which is intermediate in the hairiness of the receptacle and has been found in Cheshire, South Lancs and South-West and Mid-West Yorkshire since the year 2012. This plant, however, is completely sterile.

Large-leaved Avens is a naturalised neophyte not native to the UK, but rather a native of North America and North Eat Asia. In America it occurs as two sub-species, but apparently not in the UK.

It is found in the UK in scattered locations between Cardiganshire to Northern Scotland. Apparently it grows in woods and by paths just like Wood Avens does, so quite why in these photos it is growing in full sun and beside water is a mystery. But your Author notes that it is indeed recorded on BSBI maps in this very hectad (but not by your Author).


  Geum macrophyllum  ⇐ Global Aspect ⇒ Rosaceae  

Distribution
 family8Rose family8Rosaceae
 BSBI maps
genus8Geum
Geum
(Avens)

LARGE-LEAVED AVENS

Geum macrophyllum

Rose Family [Rosaceae]