In this week’s report from the Sid Valley Biodiversity Group, Ed Dolphin from Sidmouth Arboretum describes a project to bring a rare species of tree back to the area.

Sidmouth Herald: The Devon Whitebeam growing in Gilchrist Field. Picture: Ed DolphinThe Devon Whitebeam growing in Gilchrist Field. Picture: Ed Dolphin (Image: Ed Dolphin)

Two rare Devon trees have been found growing in Sidmouth, and they are going to be joined by more of their kind.

Two trees with large clusters of brown fruits growing in Gilchrist Meadow at The Byes have been identified as Devon Whitebeams, and Sidmouth Arboretum will be planting 30 more around the valley this autumn.

Devon Whitebeam is a distinct species in the Sorbus genus that includes Rowans and other Whitebeams. It is thought to be a hybrid, that arose a long time ago on the edges of Dartmoor or Exmoor, between the Wild Service Tree and a Common Whitebeam. Most hybrids are sterile and die out because they cannot set seed, but the Devon Whitebeam has very strange breeding habits that allowed it to reproduce.

The Devon Whitebeam has extra sets of chromosomes, four instead of the usual two, and its female ovules are self fertile,;they do not need to be pollinated to become viable and germinate. This characteristic, called apomixis, is rare in plants. Aphids do a similar thing where the female can produce several generations of babies without the bother of mating with a male; they actually give birth to baby females that are already pregnant themselves.

The fruits of the Devon Whitebeam come in bunches of what look like brown berries; actually they are pomes, related to apples and rosehips, where the fleshy part is not a botanical fruit, but that matters little when eating them. The fruits are best left until after a frost before you eat them; they have an unusual flavour often described as like almond. One use is as a stuffing for roast pheasant. You used to find them in old Devon food markets labelled as Otmast or Sorb Apples.

The Devon Whitebeam is one of the priority species in the East Devon Area of Outstanding Natural Beauty’s Species Recovery programme. Sidmouth Arboretum has secured thirty young trees, paid for with an AONB grant, to plant at ten sites around the valley with the help of the town council, Sid Vale Association, Sidbury Millennium Green Trust, and Sidbury Manor Estate.