BIRD'S-FOOT TREFOIL

COMMON BIRD'S-FOOT TREFOIL, EGGS AND BACON, TOM THUMB

Lotus corniculatus

Pea Family [Fabaceae]

month8may month8jun month8june month8jul month8july month8aug month8sep month8sept

status
statusZnative
flower
flower8yellow
inner
inner8orange
morph
morph8zygo
petals
petalsZ5
stem
stem8round

18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Here prostrate, but can also be short to medium height, max 50cm.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Here on old dunes; grows on dry grassland and is found throughout the UK, but apparently not as widespread as it was up until the 1970s.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Tends to grow in patches (which might then extend into the carpet seen above).


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Between 2 and 7 flowers atop a single stem (between 5-12 on Greater Bird's-foot-Trefoil).


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
This one has only 2 flowers, so it cannot be Greater Bird's-foot-Trefoil which dictates a minimum of 5.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
The flowers tend to radiate from a central area. Sepal teeth point more or less forwards without diverging significantly (un-like in Greater Bird's-foot-Trefoil where the lower three curl backwards, and the upper two are divergent)


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Note the two leaflets resembling stipules. Stem and sepal tube slightly hairy.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Flowers are mostly bright yellow, but orange ones can occur. Some petals tend to have narrow red stripes.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Although the flowers do have the same 5 petals as normal pea-type flowers, a banner, 2 wings and 2 keels, the view from above gives the impression of only two, the others being hidden, the large banner and a 'paw'.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
The view from below reveals that the 'paw' is in two halves, and partially hides the inner two keels.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
In Greater Birds's-foot Trefoil the upper two sepal teeth splay outwards, but not in Common Bird's-foot Trefoil.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Turning to seed, the petals turning orange-brown and then falling off leaving curved sausage balloons (the seed pods) emerging from a otherwise gaping and empty sepal tubes.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Like miniature glass-enveloped reed-relays complete with a long 'wiry' termination.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
The seed pods (fruits) are cylindrical, 15 - 30mm long (the same range of lengths as Greater Bird's-foot-Trefoil) and shiny brown/purple turning to brown. Eventually they twist and open up to release the seeds.


18th Sept 2008, Mills Hill, Rochdale Canal. Photo: © RWD
Up to 50cm high (Greater Bird's-foot-Trefoil is double that at up to 1m)


18th Sept 2008, Mills Hill, Rochdale Canal. Photo: © RWD
Leaflets of upper leaves at less than three times longer than wide (in Greater Bird's-foot-Trefoil the ratio is >4).


18th Sept 2008, Mills Hill, Rochdale Canal. Photo: © RWD
Leaflets are lanceolate or [oblanceolate to suborbicular]. (The Author would prefer to say rhombic to off-round).


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Leaves glabrous to hairy; colour greyish green.


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Hairs mostly appressed (on Hairy Bird's-foot Trefoil they are longer and stick outwards).


18th June 2012, Southport dunes, Sefton Coast. Photo: © RWD
Contrary to its common name, 'Trefoil' the leaves are not actually trefoil but only appear so although they still have two lower pairs (which are more like stipules and either wither or fall off early).


Not to be semantically confused with : Bird's-Foot (Ornithopus perpusillus), Orange Bird's-foot (Ornithopus pinnatus) (now extinct in the UK?), Bird's-foot Clover (aka Fenugreek) (Trifolium ornithopodioides), Hare's-Foot Clover (aka Hare's-foot Trefoil)(Trifolium arvense) nor with the true Trefoils (Trifoilium such as Hop Trefoil (Trifolium campestre), Lesser Trefoil (Trifolium dubium) or Slender Trefoil (Trifolium micranthum) - [all plants with similar names and belonging to the same Pea Family (Fabaceae) but in differing genera]

Easily mistaken for : Greater Bird's-foot-Trefoil (aka Large Bird's-foot-Trefoil) (Lotus pedunculatus) but that is twice as tall up to 1m, more robust, and has between 5 and 12 flowers atop a flowering stem, so if you find specimens with only two flowers, then it cannot be Greater Bird's-foot-Trefoil. It could also be mistaken for Hairy Bird's-foot Trefoil (Lotus suaveolens), but that is hairier with longer hairs.

Very similar to : Horseshoe Vetch (Hippocrepis comosa) which also has yellow flowers, but they are a deeper shade of yellow, and although often streaked with red, they are never suffused with red. It is shorter than Bird's-foot Trefoil and has multi-pinnate leaves.

There are other Bird's-foot Trefoils such as Narrow-leaved Bird's-foot Trefoil (Lotus tenuis) but that has much narrower leaves or Slender Bird's-foot Trefoil (Lotus angustissimus) which is both hairy, has between 1-3 flowers on a stalk only but is quite localised growing near the sea only in the south of England.

There is a variety : Lotus corniculatus var. sativus which, un-like Common Bird's-foot Trefoil, has hollow stems (as does Greater Bird's-foot-Trefoil) and is larger and more robust and which is often planted on roadsides and motorway verges and is probably introduced into the UK.

Some similarities to : Dragon's Teeth (Tetragonolobus maritimus) but that has solitary and pale-yellow flowers.

No relation to : Bird's-foot Sedge (Carex ornithopoda) [a sedge with similar name].

Distinguishing Feature of Bird's-foot Trefoils in general : A large banner and a smaller pod-shaped cup of petals that look like just one petal unless prised apart to reveal a further hidden three, making the normal five altogether of a Pea-type flower.

Common Bird's-foot Trefoil is a perennial plant that grows in dry grassy places. It usually has bright yellow flowers (sometimes orange to red) in small bunches of between 2 and 7 (favouring 2-5) atop a wiry stalk. The flowers have the normal Pea-type structure with 5 petals, but because of the closed structure, it looks like there are but two petals, albeit one that is pod-shaped. Because of this, one of its common names is 'Eggs and Bacon' (although the Author has never seen bright yellow or orange bacon).

Being a member of the Fabaceae family, it is expected that Bird's-foot-Trefoils would harbour toxic Cyanogenic Glycosides, and indeed some specimens do, but others do not. Contrary to expectation and the commonly accepted role of Cyanogenic Glycosides in plants (to curtail the eating habits of insects upon the plant tissue) it was found by researchers that the larvae of the Common Blue butterfly (Polyommatus icarus) fared better feeding on the leaves and tissues of Bird's-foot-Trefoils that possessed the toxins than those that didn't! They grew fatter and larger! But the adult butterflies had no preference apart from the females which preferred amino-acid rich nectar (whilst the adult males showed indifference to amino-acid content).


  Lotus corniculatus  ⇐ Global Aspect ⇒ Fabaceae  

Distribution
 family8Pea family8Fabaceae

 BSBI maps
genus8Lotus
Lotus
(Bird's-Foot Trefoils)

BIRD'S-FOOT TREFOIL

COMMON BIRD'S-FOOT TREFOIL, EGGS AND BACON, TOM THUMB

Lotus corniculatus

Pea Family [Fabaceae]