WILD TEASEL
Dipsacus fullonum
Teasel Family [Dipsacaceae] 
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Teasel Family [Dipsacaceae]
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| 10th July 2008, Partington Ind Est, Salford. | Photo: © RWD |
| Growing wild on an old industrial estate. |
| 13th Aug 2007, Kiverton Bridge, Chesterfield Canal. | Photo: © RWD |
| Spent flowerheads. |
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| 7th Aug 2007, Martin Mere, Nr. Rufford, Lancashire. | Photo: © RWD |
| The leaves are cup-shaped at the base where they join the stem, and in opposite pairs up the stem. |
| 23rd July 2006, Tyldesly Loop Line, Leigh, Lancashire | Photo: © RWD |
| The flowerheads are egg-shaped and covered in straight spines like a pin-cushion. The purple florets, of which there are many, start in a ring around the equator of the flowerhead, and spread upwards and downwards in two rings on opposite 'hemispheres'. |
| 24th June 2006, Narrow Boat Crawl, Midlands. | Photo: © RWD |
| The stems are rigid, fluted, and have a few short thorn-like prickles. The leaves are wide at their base, gradually tapering to a point. |
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| 14th July 2007, Barton Swing Aqueduct, Bridgewater Canal, Eccles. | Photo: © RWD |
| An egg-shaped flowerhead, covered in long straight spines. The numerous sepals are long and narrow tapering to a point at the ends. The edges of the sepals have a few short outwardly-curved 'thorns', reminiscent of a sword-fish. |
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| 7th July 2005, Helmsby, Cheshire. | Photo: © RWD |
| The purple florets start deep within the spines at the centre of the flowerhead. The spines, mostly light-green, are tipped slightly purple. Stems are deeply fluted (or is it ribbed) and spiny. |
| 6th Aug 2004, Castletown, Derbyshire. | Photo: © RWD |
| The florets then burst through from the centre and open up in an equatorial ring around the circumference of the flowerhead, short white anthers protruding. |
| 23rd July 2006, Tyldsley Loop Line, Leigh, Lancashire | Photo: © RWD |
| The two ring of florets migrate from the equator to the poles until all are spent, leaving diamond-shaped empty 'tubes' where they once were. |
| 23rd July 2006, Tyldsley Loop Line, Leigh, Lancashire | Photo: © RWD |
| A fully-spent flowerhead, now mostly light green. |
| 6th June 2007, Paterdale, Cumbria. | Photo: © RWD |
| The stem is much more sturdier than that of Small Teasel. Lower part has fewer and shorter spines. |
| 14th July 2007, Barton Swing Aqueduct, Bridgewater Canal, Eccles. | Photo: © RWD |
| Note the water collecting at the base of the leaves. |
| 14th July 2007, Barton Swing Aqueduct, Bridgewater Canal, Eccles. | Photo: © RWD |
| The leaves, which are in opposite pairs, cup the stem allowing water collecting to collect. The underside of the mid-rib of the leaves is spiny in a way similar to those of Prickly Lettuce and Great Lettuce. |
| Date | Photo: © Brian Carroll |
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Teasel is a biennial: in the first year it grows a low basal rosette of leaves. Only in the second year does it burgeon into a much taller and prouder plant producing spectacular flowerheads. This is similar to the way Foxglove, another biennial, behaves.
The leaves arrange themselves on the stems of plants so as not to shade their immediate neighbours too much. They have learnt how to do this aeons ago by only growing in places where they are least subject to self-shadow (by their reaction to light - chlorophyll etc). This 'body plan' has now been fixed into their genes and doesn't now need the action of light and shade to initiate it (but no doubt it is under constant monitoring - and if it drifted back into over-lapping its leaves through loss of any of these genes, it would either be able to right itself again (by its response to lack of light and natural selection) - or be lost forever, extinct). |
| 25th April 2015, Dibbinsdale, Bromborough, Wirral. | Photo: © RWD |
| The first leaves have two rows of curved spiky projections each side of the pale mid-rib |
| 25th April 2015, Dibbinsdale, Bromborough, Wirral. | Photo: © RWD |
| The curved spiked projections are atop raised bumps on the leaf surface. |
FASCIATION |
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Mutations Menu
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| July 2008, Headon Hill, Yarmouth, IoW. | Photo: (CC by 2.0) Mike Cotterill |
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You Author thinks that only the flower-head is fasciated, on account of its elongated appearance.
The leaves, which are meant to be in opposing pairs, are not fasciated, but proliferated (into a whorl). It is possible that this close group of Teasels has been affected by the same affliction, whatever that might be. They could have been sprayed with a herbicide, or it could be physical damage or an infection or infestation of some sort. |
PROLIFERATION |
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Mutations Menu
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| July 2008, Headon Hill, Yarmouth, IoW. | Photo: (CC by 2.0) Mike Cotterill |
| The flower heads on this almost recumbent example are a result of proliferation, where some part or other is abnormally replicated elsewhere - in this case not in opposite pairs, but only singly. |
| July 2008, Headon Hill, Yarmouth, IoW. | Photo: (CC by 2.0) Mike Cotterill |
| The leaves are proliferated on this example - they are usually just in opposite pairs, but here there are many in a whorl (but the elongated flowerhead at the summit is as a result of proliferation). The stems are also abnormally robust and thick. It is very likely that the same abnormality in these plants has triggered all these different aberrations. |
| July 2008, Headon Hill, Yarmouth, IoW. | Photo: (CC by 2.0) Mike Cotterill |
| Proliferation of flower heads (where they are normally in opposite pairs) abounds on this specimen, especially at the summit. |
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Some similarities to : Spear Thistle flower heads.
Related to: Small Teasel, Wild Teasel starts flowering in a band around the middle of the head, which then spreads upwards and downwards, with the middle petals falling out as the flowers progresses up and down. Eventually, all the petals have dropped off leaving a myriad of holes. A yellow dye can be extracted from this plant. The birds love the seeds. Spreads rapidly around the same area by bird-dropped seed. Starting from a lowly single plant, the annual gain factor is about 20, but that will quickly saturate as the inner areas become over-crowded, when only at the periphery can further propagation progress. Habitat includes rough grassy or shrubby ground and waste places. Wild Teasel is an example of a protocarnivorous plant, one which can physically trap insects (in the case of Wild Teasel by the pool of water that gathers at every pair of leaves where they join the main stem. It is not fully carnivorous, lacking the enzymes necessary to dissolve the insects, but relies more on natural decomposition. Although Wild Teasel is fully capable of growing without insects, it has been proved that it produces more seeds (but does not itself grow taller or more vigorously). The prickly seed heads, when dried, are used as ornamental decorative flower arrangement.
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 Dipsacus
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fullonum
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Dipsacaceae
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 Dipsacus (Teasels) |
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Teasel Family [Dipsacaceae]
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