Sunday, 14 August 2011
This is Red Bartsia, or Odontites vernus, growing at the edge of a path in Crookes Recreation Ground, Sheffield. It's not unusual to find it on waste ground or trampled path edges, but it is easily overlooked. Like all members of the Orobanchaceae it is parasitic; in this case on the roots of grasses I believe. It's green, so obviously it can still photosynthesize, so we might suspect it is only using its hosts for mineral nutrients and water. However, the line between hemi-parasitism (as here) and holo- or complete parasitism seems to be fairly thin in an evolutionary sense, so it's possible that some sugars are received from the host as well.
A nice plant to look out for in urban situations; I used to see it a lot in Birmingham along the canal in the Edgbaston area.