Sunday 3 May 2020

An hour in Bridgnorth Cemetery, by John Handley

Though well recorded, Bridgnorth Cemetery is a short walk away from where I live and each year I enjoy a brief, but joyful display of a near threatened species in Great Britain.

Teesdalia nudicaulis in Bridgnorth Cemetery
Teesdalia nudicaulis, Shepherd’s Cress has been in decline for quite some time with many losses being recorded before the 1930’s.  T. nudicaulis favours open, free-draining, periodically disturbed shallow gravelly or acid soils.  In Shropshire it is typically associated with rabbit scraped heath grassland and upland screes as here on the edge of the Long Mynd:

The basal rosette of Teesdalia nudicaulis

Teesdalia nudicaulis showing the compressed spoon shaped fruits
The map below displays records of Teesdalia nudicaulis in Shropshire since 2000, showing records from Bridgnorth in the south east of the county, and Prees Heath in the north.  It’s most conspicuous presence is on the Long Mynd in the south, and Earl’s Hill just to the north.  Haughmond Hill near Shrewsbury and then Bulthy Hill to the west are the bulk of most of the remaining records with some scattered sites on the hills to the west.

The more recent losses in the lowlands are probably due to encroaching scrub. It is a winter-annual therophyte which means that it germinates and grows in the autumn, overwinters and then flowers and seeds when conditions are favourable in the spring, generally between March and June depending on the intensity of the spring sunshine.

In Bridgnorth Cemetery it grows where there is disturbance from rabbits which, I’m pleased to say, is currently a healthy population. It is reported to have a very short-lived seed bank which is a concern because without the disturbance from the rabbits, a closing sward won’t favour the germination in the autumn.  However there is some evidence from the Breckland Heaths that suggests that it might be more persistent than initially assumed and might have the potential to re-establish if there is further disturbance.

For more details see the BSBI Teesdalia nudicaulis, Shepherd's Cress species account