In this journey of ours through life, it is amazing how many varieties of plants we encounter just walking down the street. When you research them it is amazing what you find. Like for example Rhus glabra which I came across yesterday on my walk. It is also known as Scarlet Sumach, Upland, Pennsylvania Sumach, Vinegar Tree, or Smooth Sumach. Of course Sumach, Sumaq, besides being a shrub or a family of plants is a well-known spice that is actually derived from the dried fruits of some species of Rhus. Not this one!
The spice Sumach is derived from the dried fruits of Rhus coriaria, a sour reddish-purple powder used especially in middle-eastern cuisine. You might also see it sprinkled on Hummus and Tashi. It is an ingredient in falafel and Persians added it to their Chelo-Kabab. However, in North America, Rhus glabra is used to make a beverage tasting similar to lemonade.
You can distinguish the non-poisonous varieties by observing their fruit which is clothed with acid crimson hairs, with compound, dense panicles; the poisonous species have smooth fruits and axillary panicles and smooth fruit. Some well-known poisonous species include Rhus toxicodendron or Poison Ivy, Rhus diversiloba or Poison Oak, and Rhus vernix or Poison Sumach. All three contain a substance called urushiol which causes an allergic reaction in humans.
Anyway, I came across this tree when it is in bloom and hopefully in the near future I will get to see the fruits! All this time I had no idea where this spice comes from. Rhus glabra has grayish bark and bluish-green pinnate leaves and in contrast, the flowers are yellowish-green. Due to the high content of tannins, the leaves have been using in the tanning of leather, whereas the bark is used for dyes. It should be planted in full sun and in well-drained, soil, it tolerates most types of soils. Rhus glabra can grow up to 2.5m or 8ft.
This variety originates in North America and it is hardy, it can tolerate frosts down -20°C of -4°F. It is a clump-forming, deciduous shrub that produces and propagates through suckers. It belongs to the Anacardiaceae family of plants. Rhus glabra can grow very wide in fact it could be as wide is it is high, therefore you can prune this tree each year to maintain its shape. You can also propagate this shrub, by wood cuttings or root cuttings in autumn.
In autumn the leaves turn nice shades of yellow and red giving the landscape rather nice punch of color. The shrub blooms in early summer and since this shrub comes in male and female fruits will only appear on the female plants. Rhus glabra fruits appear in autumn and are reddish in color and they hang in clusters and covered in a crimson down that is very sour to the taste as it contains malic acid, to preserve its acidity they should be picked before rain or water touches them. This plant is used in medicines.