Rare fleshy-fruit creating Knotweeds (Polygonum spp.)

Knotweeds (Polygonum spp.) are over 200 species of herbs, which occur mainly in temperate areas and create small dry fruits (nutlets) which often are edible (were eaten in the past). But there are a few exotic species which born fleshy fruits. I grew two of them - Polygonum perfoliatum and Polygonum chinense.

The infrutescence of Devil's Tail (Polygonum perfoliatum) - large subtropical prickly climber

Devil's Tail – Polygonum perfoliatum (other names: Persicaria perfoliata, Mile-a-minute, Giant Climbing Tearthumb, Asiatic Tearthumb) this is subtropical annual (or tropical perennial), large and very dense, prickly climber to over 2-3m (7-10ft) tall and wide. This is used as vegetable (tender young leaves and shoots with acid flavor - raw or cooked) and its fleshy fruits are also edible (ripe blue fruits are eaten fresh as snack together with seeds - they taste like delicious nuts). Also very ornamental, unusual herb. The triangular leaves with prickly petioles resemble a tail of a devil in shape - what gave the name to this plant. The seeds are hard to fing in trading. They need to germination about 2-3 months of cold stratification (the best to sow them in cool cellar in late autumn/early winter). 

The top of young plant (end of May)

Plant with first flowers (half of June)

An inflorescence

It creates dense prickly thickets

A mature plant 2 m (7 ft) tall

The fruits are edible

They taste like nuts and are eaten together with seeds

This climber is terribly prickly

The fruits (blue) and 1 seed (black)

The base of plant is something woody

This plant likes moist or even wet soil, but well drained and is resistant to waterloging if grown in large pot

An each ocrea (characteristic to knotweeds) is widely winged in this species

This year I sown also an other fleshy fruit bearing knotweed - Chinese Knotweed (Polygonum chinense). It is large perennial herb which creates sweet (my friend which gave to me the seeds wrote that the taste is described as acid in botanical papers, but fruits which he harvested were sweet) fleshy edible fruits. The seeds of this species germinate easily without any pre-treatment. My plants were origin to Philippines. They are not in flowers yet. I hope that they survive winter on the window sill and will bloom in next year.

This species more resembles common knotweeds in appearance than previous one

There are visible ocreas (in the bases of leaf petioles on stem)

 If you have available seeds of any other fleshy fruit species of Knotweed, please write to me.