Wednesday wildflower: groundsel.

When I was young, about 11 or 12 I guess, I caught a budgie on the neighbor's front lawn.  I spotted him through the kitchen window, a flash of brilliant blue struggling against the Wellington wind.  When he settled on the lawn I ran over there and flung my tee shirt over him, and carefully carried him home.  We tried to find his owner, but eventually we gave up and Bluey became part of our household.  I never managed to teach him to talk, but he did have a cheerful whistle.

The neighbors told me to hang a sprig of groundsel in his cage, so I'm pretty sure groundsel was one of the first weeds I ever learned the name for.  I scoured the garden for it, and even today I always notice groundsel, even though it must be 45 years since Bluey died.

Senecio vulgaris leaves (A, abaxial; B, adaxial) and flower heads at flowering (C), early fruiting (D) and after fruiting (E).

Groundsel, Senecio vulgaris, is a common weed of cultivated ground.  The flower heads lack ray florets, but are otherwise similar to other senecioids, like Roldana.  The loss of rays and the smaller stigmas in S. vulgaris suggest self-pollination, but the mating system seems not at all straight-forward.  Some plants in Europe do produce rays, but New Zealand populations of S. vulgaris are reported to be all rayless (Webb et al., 1988).  Ray production is controlled by a group of regulatory genes, which are expressed (or not) in the outer florets of a head (Kim et al., 2008).  In conditions where self-pollination is advantageous, raylessness is favoured.

References.

Kim, M; Cui, M.-L.; Cubas, P.; Gillies, A.; Lee, K.; Chapman, M.A.; Abbott, R.J.; Coen, E. 2008: Regulatory genes control a key morphological and ecological trait transferred between species.  Science 322: 1116–1119.

Webb, C.J.; Sykes, W.R.; Garnock-Jones, P.J. 1988.  Flora of New Zealand Vol. 4.  DSIR, Christchurch.