Confusing Restharrows - a question

[leifus]

there's Ononis repens (common restharrow) and Ononis spinosa (spiny restharrow)

I found what I thought was Ononis repens, but there was an occasional spine on the plant, like Ononis spinosa (which it definately wasn't). It was growing with lots of normal O.repens.

Is this a spiny form of O.repens or a very un-spiny form of O.spinosa?

[Rambling Rob]

I am also confused about spiny Restharrows!

Earlier this year I found some very spiny Restharrow at Whitecliff Bay, but Ononis spinosa is reckoned not to occur on the IoW.

Not just the occasional spine but regular large hard spines.

I was back there a few days ago and took several pics - here's one:



How spiny can it be and still not be Spiny Restharrow, I wonder?

Rob

[PeterJL]

Very Spiny. Spinyness is not the key character of spiny rest harrow even though it ought to be.

[Tiggrx]

The spiny form of Ononis repens is called var. horrida and can be very spiny.

Some differences to look for are:

*Stems hairy all round, leaflets <3x as long as wide - O. repens

*Stems mainly hairy along 1 side or 2 opposite sides, leaflets >3x as long as wide - O. spinosa

[Rambling Rob]

I have read that bit about the hairy stem characteristic in the key before but it is difficult to sort out under hand lens, I find, with the hairs being quite long, tangly and awkward to identify their origins as in a line or not.

Can someone provide a pointer to photos which illustrate this clearly?

Presumably someone has seen both species and photographed them up close to show the important features?

Another feature to look for acc. to the key is that the wings of the O. spinosa flower are shorter than the keel - which is the case in the photo above, I think, but how reliable is this I wonder?

Rob

[leifus]

thanks for the info I'll check tomorrow

Rob - that looks like spinosa to me....

[Rambling Rob]

I reckon the leaflet is probably going to be the most convenient indicator in the field - >3 times as long as broad for spinosa, as mentioned by Tiggrx above - and looking at the pics from Whitecliff my Restharrow clearly fails that test.

That said, next time I'm there I'll make sure to have a scale and do some measurements.

Rob