This species was originally included as S. latifolia 'Devon form' (i.e. S. devoniensis) from Watersmeet, but identified as the ‘No Parking Tree’. Then named by M. Proctor in 2009, the specific epithet ‘admonitor’ was initially used by E. F. Warburg as a joke relating to the ‘No Parking’ notice (i.e. to admonish).
The taxonomy of the Sorbus complex has undergone considerable revision in recent years. In particular, Sennikov & Kurtto (2017) published a comprehensive checklist proposing the recognition of several segregate genera based largely on molecular phylogenetic evidence. Under this treatment, the traditional genus Sorbus was divided into distinct genera including Aria, Cormus, Torminalis, Hedlundia and Karpatiosorbus.
However, these changes have not been universally accepted. More recent authors have adopted alternative classifications, with some merging several of the segregate genera again, while others, including Tim Rich et al in his recent treatment of the British flora, continue to recognise Sorbus in the traditional sense pending wider taxonomic consensus.
For reasons of stability and familiarity, Trebrown currently follows the traditional broad concept of Sorbus on this website, while acknowledging the alternative modern classifications. See our full Sorbus report.
Sorbus admonitor is a member of subgenus Tormaria with leaves with acute, triangular lobes and greenish-white-tomentose undersides, and orangey-brown fruits. Sorbus admonitor differs from S. devoniensis in having glossier, more deeply toothed and somewhat narrower leaves; S. devoniensis sensu stricto does not grow in the Watersmeet Valley area and the two species have not been confirmed growing together. Sorbus admonitor differs from S. subcuneata, with which it does grow, in having broader leaves with rounded bases, and a denser crown.
Sorbus admonitor has presumably originated from S. devoniensis, to which the peroxidase pattern was most similar (Proctor et al. 1989), rather than as a new primary hybrid between Sorbus torminalis and Sorbus aria or from S. subcuneata.
Trebrown Nurseries maintains our own seed stands on Trebrown Farm from seed collected under special Natural England license for its species recovery programme.
