What Is Mimosa Hostilis Root Bark? Names, Origins and Uses
Mimosa hostilis root bark, often shortened to MHRB, is the inner root bark of a small thorny tree that grows in Mexico, Central America and north-eastern Brazil. Craftspeople value it for two things: a very high tannin content and a deep purple-brown colour. This guide explains what the bark is, what it is called, and how it is used today.
The tree behind the bark
The tree’s accepted botanical name is Mimosa tenuiflora; Mimosa hostilis is an older name that is still the most common one in trade. It belongs to the pea family and grows to around eight metres, with fern-like leaves, thorny branches and white, fragrant flower spikes. It is a tough pioneer species that regrows quickly after cutting or fire, which is one reason it has been used by local communities for so long.
One bark, several names
- Tepezcohuite – the name used in Mexico, where the bark is a familiar ingredient in soaps and creams.
- Jurema preta – the name used in Brazil, where the tree is typical of the dry caatinga region.
- MHRB – the abbreviation used by dyers and suppliers in English.
What makes the bark useful
The inner root bark is rich in tannins and natural pigments. Tannins bind readily to fibres and hides, which is why tannin-rich barks have been used for tanning leather and dyeing cloth for centuries. The pigments give colours from soft pink through purple to dark brown.
How it is used today
Natural dyeing
Dyers simmer the bark in water to make a dye bath for wool, silk, cotton and leather. The shade depends on the fibre, the amount of bark and any mordant or modifier used.
Soap making
Soap makers add the powder, or a strained infusion, to cold-process and melt-and-pour soap for natural colour.
Cosmetic formulation
In Mexico, tepezcohuite is a traditional ingredient in handmade and commercial creams, balms and masks.
Whole, shredded or powder?
The bark is sold in three forms. whole root bark stores longest and can be processed as you need it. The shredded root bark strains cleanly out of a dye pot. The root bark powder releases colour fastest and blends easily into soap and cosmetics.
A note on intended use
We sell Mimosa hostilis root bark as a raw material for dyeing, soap making, cosmetics and other crafts. It is not sold for human consumption.
Common questions
Is Mimosa hostilis the same plant as Mimosa tenuiflora?
Yes. Mimosa tenuiflora is the accepted botanical name. Mimosa hostilis is an older name for the same species that remains common in trade.
Why is the root bark used and not the trunk bark?
The inner root bark holds the highest concentration of the tannins and pigments that dyers and tanners want, which is why it is the part that is harvested and sold.
What colour is the bark?
The inner face is pink-purple to reddish-brown. Ground to powder, it looks purple-pink to brown.
Does harvesting kill the tree?
It does not have to. Mimosa tenuiflora regrows vigorously, and careful harvesters take only part of the root system from mature trees.
