Know your Rhubarb

Rhubarb is a group of plants that belong to the genus Rheum in the family Polygonaceae.

They are herbaceous perennial plants growing from short, thick rhizomes.

They have large leaves that are somewhat triangular shaped with long fleshy petioles.

They have small flowers grouped in large compound leafy greenish-white to rose-red inflorescences.

Although the leaves are toxic, various parts of the plants have medicinal uses.

Fresh raw stalks are crisp (similar to celery) with a strong tart taste; most commonly the plant's stalks are cooked and used in pies and other foods for their tart flavour.

A number of varieties have been domesticated for human consumption, most of which are recognised as Rheum x hybridum by the Royal Horticultural Society.

Rhubarb is botanically classified as a vegetable; however, in the United States a New York court decided in 1947 that since it was used in the United States as a fruit it was to be counted as a fruit for the purposes of regulations and duties, and a side effect was a reduction in taxes paid.

In warm climates, rhubarb will grow all year round, but in colder climates the parts of the plant above the ground disappear completely during winter, and begin to grow again from the root in early spring.

It can be forced, that is, encouraged to grow early, by raising the local temperature.

This is commonly done by placing an upturned bucket over the shoots as they come up.

Because rhubarb is a seasonal plant, obtaining fresh rhubarb out of season is difficult in colder climates, such as in the UK.

Rhubarb can successfully be planted in containers, so long as the container is large enough to accommodate a season's growth.

The colour of the rhubarb stalks can vary from the commonly associated crimson red, through speckled light pink, to simply light green.

Rhubarb stalks are poetically described as crimson stalks.

The colour results from the presence of anthocyanins, and varies according to both rhubarb variety and production technique.

The colour is not related to its suitability for cooking.

The green-stalked rhubarb is more robust and has a higher yield, but the red-coloured stalks are much more popular with consumers.

Rhubarb is grown primarily for its fleshy petioles, commonly known as rhubarb sticks or stalks.

The use of rhubarb stems as food is a relatively recent innovation, first recorded in 17th century England, after affordable sugar became available to common people, and reaching a peak between the 20th century's two world wars.