Tuesday, 15 January 2008

Late or early?

One thing I've noticed since I started recording is that spring and summer flowering plants often have a late second push in autumn, if the weather is warm enough. Many species do this, including: Hogweed, Cow Parsley, Nipplewort, Ragwort, Herb Bennet and Bush Vetch. Other flowering plants seem to flower all-year round, now. These include: Daisy, Dandelion, Sow-thistles, Smooth Hawkbit, Herb Robert and Groundsel. But what do we have when I find a specimen of Hogweed in full flower in January?

Is it early for 2008 or late for 2007? I think the answer is fairly clear: the new stem growth for 2008 hasn't even started yet, so it has to be late for 2007. But what is it trying to do? The pollinating insects are all dead (and won't be back until April/May), so it can't reproduce (and it would be unlikely that there would be another specimen close enough to pollinate anyway). It must be worthwhile, or the plant wouldn't be expending all this energy on making flowerheads. Maybe it's a mechanism whereby it is preparing for all-year round insects as we warm up. What do you think?

Other late-flowering species:

Bush Vetch



Smooth Hawkbit

And just to finish off, a couple of shots of Winter Heliotrope, which only flowers during December and January around here:



9 comments:

Anonymous said...

Well, something is pollinating the hogweed round here (Yorks) since the fruits appear to develop - no idea if they're viable seeds of course.

Dawrodboolyer said...

Hogweed is not native so maybe it has different cues on flowering,
or maybe its head is just turned!

Stuart said...

Hogweed - Heracleum sphondylium - is native..it's Giant Hogweed - H. mantegazzianum - that's naturalised/introduced. This common mistake is one of the reasons why harmless Hogweed is regularly chopped at ground level. Angelica too, for that matter.

Ray said...

The HDRA say that Hogweed is 'self-compatible' so it can manage without insects apparently.
I must go and get some photos of a large colony of Winter Heliotrope which grows in a shaded lane in the village!

Stuart said...

'Self-compatible', eh. Handy, and very flexible.

I generally find W. Heliotrope on damp bends in the road in very similar places to Butterbur.

Stuart

Gill said...

"HDRA" ???

Ray said...

HDRA : Henry Doubleday Reseach Association
http://www.gardenorganic.org.uk/

Jenny said...

There has been Hogweed flowering round here (Co.Cork) since the summer, and I've just seen several clumps of Round-leaved Water-crowfoot in flower. Far as I remember that started flowering in January last year too.

Dawrosbloger said...

oops, sorry about that Hogweed comment.