Dandelion (Taraxacum officinale)
After two green months, my lawn is once again showing the yellow heads of short-stalked dandelions, the sort that subvert all my efforts with the mower. Last week it struck me that I had not seen those dangerously invasive flower heads since much earlier in the summer. I then realized, with dismay, that it was 9 weeks (63 days!) since the summer solstice. And that if you count 9 weeks before the solstice you reach back to 19th April — the spring flowering period of the dandelion. The daylength would be the same on 23rd August as it was on 19th April. It had not occurred to me before that plants whose flowering is regulated by daylength (and there are many), could have two flowering seasons, equidistant from the solstice.
I wonder if this is the right explanation.
The roadside verges are also lined again with yellow composite flower heads, at their densest right by the edge of the tarmac, as though they craved the pollution, or salt, splashed up from the road. It is very reminiscent of the spring flush of dandelion blossom, which similarly is densest right up by the road, though these autumn flower heads are subtly smaller. If you dismount and pluck a stalk you find it is not hollow, nor smooth, nor does it exude a milky latex; in fact it is not a dandelion at all. The narrow stalk, occasionally branched, has tiny bracts on it, clasping the stem.
The flower is (probably) the Autumn Hawkbit, Leontodon autumnalis. (Note in passing that Leontodon is modern 'Greekolatin' for dents de lion — 'lion's teeth'.)