Single-leaved ash is a cultivar of Narrow leaved ash and is very rare across Exeter. As the name suggests it has one leaf rather than the usual 3 to 6 pairs of opposite spaced leaves that most Ash species have. It shares almost identical characteristics of Narrow leaved ash such as the dark buds and the curling branches. Interestingly it tends to flower a bit later than Narrow leaved ash and the flowers are usually present in April. It is not clear how resistant this cultivar of Ash is against Ash Dieback. Please note that during my initial study I believed this to be a One-leaved ash (Fraxinus excelsior 'Diversifolia') but it does appear to be a Single-leaved ash (fraxinus angustifolia 'veltheimii'). So a majority of my Social Media content may still refer to this as a One-leaved ash - sorry for any confusion!
There is very little information about this tree on the web as it's a very unusual cultivar but to keep things simple treat this like a Narrow leaved ash with the exception of the leaf formatation. If you manage to spot one of these unusual trees on your travels in Exeter then you are very lucky!
The shape is lanceolate and the edges are loosely serrate
The branches and twigs tend to be quite curly
Altough the tree is named a single-leaved ash there can sometimes be two smaller leavers on the same petiole. The single leaf is ususally between 12 to 18cm in length and about 6cm wide. The shape is lanceolate and the edges are loosely serrate. The buds are black / dark brown and if compared to a twig of a Narrow leaved ash would be very hard to tell apart. The end branches tend to be quite curly.
These male flowers are beginning to release their pollen
The black / dark buds are a key characterstic of this species of Ash
The flowers are very unusual and often go unnoticed. They appear in the late spring and are coral like formations of green and red / purple. Just like with Narrow leaved ash it's dioecious so the trees aretypically either all male or all female. In some cases the trees can have both male and female flowers. Also, one year it could be a male tree and the next year a female tree - or vice versa. So a very diverse tree when it comes to the flowers.
The canopy is quite open and allows a good amount of light to the ground
The underside of the leaves is pale green and fairly smooth
It would be nice to see more of these trees across Exeter, however, due to the spread of Ash Dieback there are very tight restrictions in place when it comes to being able to buy certain species of Ash.
If there is anything out of place or wrong please contact me. Equally if there is anything you wish to add please let me know. The more information we have about Single-leaved ashthe better. Many thanks!