Rhus

Stag’s horn sumach is native to the north-eastern parts of North America. It is a suckering tree or shrub which thrives in full sun, on sandy slopes or along roadsides.

The attractive leaves are composed of multiple leaflets, which in autumn take on all possible shades of yellow, orange, red and violet. In summer it bears small green flowers in erect cones, 20cms, which in the females change in autumn to handsome glowing red spikes of berries coated in red hairs, which remain on the tree after the leaves fall.

At Mustila, this showy but slightly tender shrub is being test-grown in small groups in different parts of the Arboretum, but the best individuals have been left to grow in the nursery for seed production. The seed provenances under test have all been collected on Mustila’s own expeditions to the north-eastern edge of its range, in Quebec, Canada. After the tender seedling stage their hardiness has been astonishingly good.

Neither stag’s horn nor the related species variously know as scarlet, smooth or upland sumach (R. glabra), also growing at Mustila, causes skin irritation. The bad reputation of sumachs in this respect is due to the so-called poison ivy (Toxicodendron radicans), which was earlier thought to be one of the sumachs, but is now classed under a different genus, Toxicodendron.

Scarlet sumach is native to North America, mainly the eastern parts of the continent, but can be found in almost every state of the Union, as well as in southern Canada. It is a suckering tree or shrub which thrives in full sun on sandy slopes and roadsides. One of the common names refers to the hairless branches, which are the best distinguishing mark from its near relation, the stag’s horn sumach (R. typhina).

The attractive foliage has multiple leaflets, whose autumn colours range through all possible shades of yellow, orange, red and violet. In summer the small green flowers are in erect dense panicles up to 20 cms, which on the female plants turn brilliant red in September. The fruit is a berry covered with red hairs, remaining on the shrub in erect clusters after the leaves have fallen. The berries have been used to make juice, to give aromatic citrus flavour to soft drinks, and in medications. Dyes obtained from various parts of the plant were in general use in the 1800s but the spread of artificial dyes has replaced them. 

Several of these showy scarlet sumach shrubs have been planted for testing in various parts of the Arboretum, though they are considered rather winter tender.