Things that are not rhubarb

Rhubarb is the common name for several different plants. Most of these are incorrectly called rhubarb, or have names that somehow relate them to rhubarb because they look like rhubarb. Here is a short list of some of the plants that I know are confused with garden rhubarb.

• Beta vulgaris - Spinach rhubarb - Not a rhubarb at all but has rhubarb like leaf stems (thick and bright red). 
• Arctium lappa - Greater burdock, Edible burdock, or Lappa Burdock - A burdock that is commonly cultivated in gardens for its root used as a vegetable (the leaves and roots are also edible). This plant is commonly found in the wild (its a weed) and when young is easily confused for rhubarb.

 

Burdock

• Rumex alpinus - Monk's Rhubarb, Garden Patience - Monk's Rhubarb is a Dock bearing the name of Rhubarb for some purging quality. The root-stock is very stout, yellow color; the stem 2 to 4 feet (60-120 cm) high, bearing pale green leaves, broad and very long, the edges waved, but not cut into. The tops of the stems are divided into many small branches, bearing reddish or purple flowers, succeeded by angular seeds, as in other docks. The medicinal virtues of the root, when dried, are similar to the Garden Rhubarb, but are not so strong.
• Rumex hymenosepalus - Wild Rhubarb, Red Dock, Desert Ginseng - Indians used the roots to soften their buckskins since it contains tannin. The root was used to make tea for treating diarrhea and as a gargle for easing sore throat. The plant was also used as a source of dye (yellow hue in dyeing wool - stalks are an excellent substitute for rhubarb. This plant is a native of Western US. The bitter succulent leaves were roasted on hot ash beds. (Young leaves of some species are more edible, and even used to be cultivated as a vegetable in Europe.
• Gunnera manicata, Gunnera tinctoria - Giant Rhubarb, Giant Gunnera - Huge plant, mammoth, wrinkly, dark green leaves to 9 feet (3 meters) across on stout prickly stems grow from a pink, fuzzy, watermelon-sized crown. Creates a bold, tropical look for sheltered, damp spots. Large cone-shaped flowers, 5 inches (13 cm) across at the base and 2-3 feet (1 m) tall, change from green through red, and brown. Needs a covering of bracken. Magnificent in summer. Ideal for lakes, large ponds, damp ditches, etc. A very conspicuous plant for the pond-side or boggy spot.

 

Gunnera - Giant Rhubarb

• Reynoutria japonica - Japanese Knotweed, Donkey Rhubarb - Forms thickets of stout, rather zigzag, red-brown stems up to nearly 6 feet (2 m) high, with broad pointed leaves straight at the base. Flowers white and feathery. Many of us know it as Donkey Rhubarb - presumably because one would be a donkey to attempt to eat these rhubarb-like stems. Also known as Polygonum cuspidatum. A very aggressive invader of disturbed and shaded habitats.
• Darmera peltata - Indian Rhubarb, Umbrella plant, S axifraga peltata, Peltiphyllum peltatum - Leafless, early spring stems of rich pink flowers emerge from the damp soil to 2 feet (0.6 meter), to be replaced later by enormous, umbrella-like leaves that color richly in autumn if grown in full sun. An outstanding American native. Will tolerate some periods of standing water.  Pink flowers emerge in spring, replaced by large round leaves later. 
• Petasites japonicus - Petasites hybridus, Butterbur, Bog Rhubarb, Plague Flower, Langwort, Flapperdock, Blatterdock, Capdockin, Bogshorns, Butter-Dock - It has a fleshy, stout root-stock, extensively creeping, which, like the Coltsfoot, sends up the flowers before the leaves appear. The flower-heads are, however, not produced singly, on separate stalks, but in crowned clusters in a dense spike, with many bracts interspersed, at the summit of a round, thick flower-stalk, 4 inches (10 cm) to a little over 1 foot (30 cm) in height, which first appears in late winter or very early spring, and is generally of a purplish hue. Leaves formerly used as rain hats and for wrapping butter; contains toxic alkaloids; used externally in herbalism; flowers used in an attempt to cure bubonic plague.