SUBTERRANEAN CLOVER

BURROWING CLOVER

Trifolium subterraneum

Pea Family [Fabaceae]

month8may month8jun month8june

status
statusZnative
flower
flower8white
flower
flower8cream flower8white
inner
inner8red
morph
morph8zygo
petals
petalsZ5
stem
stem8round
rarity
rarityZuncommon

10th May 2008, Alverstone, IoW. Photo: (CC by 2.0) Geoff Toone
Another usually prostrate clover, but one whose fruiting heads have the most unusual habit of burying themselves underground at the fruiting stage, thus ensuring that they are ready to grow into new plants. With that mechanism in place, you could be forgiven for thinking that Burrowing Clover (aka Subterranean Clover) was ubiquitous, but it is a rare [R].


7th May 2010, Sandown Airport, IoW. Photo: (CC by 2.0) Geoff Toone
Whilst the inability to spot fruits on the plant might not be a reliable identifying strategy for this clover, the white to cream flowers with their very long, exposed tubular corolla tube is unique feature (for Clovers).


10th May 2008, Alverstone, IoW. Photo: (CC by 2.0) Geoff Toone
Another identifying feature of this clover is that the flowerhead consists of just 2 to 5 florets (up to 7). There are, however, the numerous empty calyxes (with palmately-divided teeth) of sterile 'flowers' (but your Author has not found any in these photos). The calyx tube also has a red band around it up to the calyx teeth (which are green).


7th May 2010, Sandown Airport, IoW. Photo: (CC by 2.0) Geoff Toone
The leaflets are oval and almost round. Their veins are nearly straight.


7th May 2010, Sandown Airport, IoW. Photo: (CC by 2.0) Geoff Toone
The veins by transmitted light.


22nd April 2011, West Green, St. Helens, IoW. Photo: (CC by 2.0) Geoff Toone
The flowers are between 8 to 14mm long. Here 3 are presented on a long stalk. There is a dark-brown object in lower right-hand corner - could this be an as-yet unburied fruit??


22nd April 2011, West Green, St. Helens, IoW. Photo: (CC by 2.0) Geoff Toone
The calyx tube has a distinctive red band around its central portion but the long thin calyx teeth are wholly green as is the lower cup-part of the calyx tube. The flowers themselves, on their extraordinarily long corolla tube, only open partly. In particular the 2 wings are nearly as long as the banner.


22nd April 2011, West Green, St. Helens, IoW. Photo: (CC by 2.0) Geoff Toone
Leaves hairier than rest of the plant. The only other indentifying feature is one you cannot see: the fruits burrow themselves underground!


Lookee-Likees : Flower ()

Uniquely identifiable characteristics: For a Clover - the flowers and the un-seen buried fruit (see photo captions)

Distinguishing Feature :

Burrowing Clover, aka Subterranean Clover, gets its name from the fact that the fruits burrow themselves underground, in effect, planting themselves. This must also mean that it spreads slowly outwards, and cannot suddenly appear elsewhere (although Clive Stace does say that it is a wool-alien which frequently appears elsewhere but in a much sturdier form [var. oxaloides] - so the fruits might have burrs on them which allows them to stick to the woolly coats of animals. The mind boggles - burrowing sheep??)...

It is a native plant which is found on partly bare sandy places near the sea on the southern coasts of England. It also grows well inland on short turf, in a very broad band around the River Severn. But it is an uncommon [R] plant.


  Trifolium subterraneum  ⇐ Global Aspect ⇒ Fabaceae  

Distribution
 family8Pea family8Fabaceae

 BSBI maps
genus8Trifolium
Trifolium
(Clovers)

SUBTERRANEAN CLOVER

BURROWING CLOVER

Trifolium subterraneum

Pea Family [Fabaceae]