Dyeing plants are a valid alternative to the chemical products commonly used for dyes and dyeing and painting with natural pigments are ancient arts that date back to the origins of humanity and draw their raw materials from the infinite varieties of the plant, animal and mineral world . The practice of producing natural dyes is as well known as widespread and implemented for millennia for artistic, ritual, ornamental, cosmetic and food purposes.
Coloring plants have had immense importance in economic and political history, in cultural exchanges, in the arts and in the development of sciences and techniques. Some vegetables, the best known for their coloring properties, have been cultivated and traded, becoming important economic agents and influencing the development of entire regions.
When processing vegetable dyes, ranging from extraction to use on a support (paper, fabric, wood, clay, leather), different processing procedures are used depending on whether they are extracted from flowers, berries or roots, barks, leaves, and specific binders depending on the material to which the color is to be applied. Almost all dyes require a support treatment that allows them to penetrate its molecular structure and adhere to it in a stable manner. In textiles the treatment consists in boiling in water between 70 ° C and 90 ° C, with the addition of metal salts and is called mordant. Pigments are extracted from most plants by maceration and decoction in water. The etched material is immersed in the color bath, containing the previously extracted coloring principles, and then dyed with suitable and specific times and temperatures according to the different pigments.
The shade and brilliance of the colors obtained from the plants are characteristic of the single species, but vary within the same color for different plants. Pigments are present in plant tissues in plastids and vacuoles in the associated form of substances of different chemical nature such as flavonoids, carotenoids, anthocyanins, and indigoids.
Until a little over a century ago the colors were exclusively of natural origin, then with the fine tuning of the synthetic colors, whose use spread rapidly in the industrializing countries, the practice of natural dyeing was increasingly limited in particular areas (artistic and textile handicrafts, food coloring). In recent decades, the greatest attention to the qualitative aspects of life (organic food, bio-architecture) has stimulated a strong interest in natural dyes, thus developing important cultural and productive projects for some traditional dyeing species such as madder, ford and blonde reseda. In this perspective botanical gardens can be proposed as new interesting places of experimentation and recovery of the traditional and historical culture of natural dyeing, complemented by the most recent biological knowledge.
Color has always been an art of memory, which differs from one society to another and changes over time. Color is the organization chart of social life, and it is what it takes to classify to associate, to oppose, to designate, but it is also what it takes to dream.
The following is a list of plants that can be used as a whole, or for parts of them, as dye plants.
Acacia catechu Willd. – Catechu – resin – Brown
Achillea millefolium L. – Common yarrow – top – Yellow
Aesculus hippocastanum L. – Horse chestnut – bark and leaves – beige / brown
Alchemilla xanthochlora Rothm., 1937 – Lady’s mantle – plant – Rose / coral
Alcea rosea L. – Common hollyhock – flowers and leaves – Blue / violet
Alkanna tinctoria Tausch L. – Alkanet – stem and root – Red
Baptisia tinctoria (L.) R.Br. ex Ait.f. – Wild indigo – root – Blue / purple
Berberis vulgaris L. – Barberry – bark – Yellow / brown
Betula pendula Roth, 1788 – Silver birch – leaves – Yellow
Bixa orellana L. – Achiote – seeds – Yellow / orange
Calendula officinalis L. – Pot marigold – flowers – Yellow
Calluna vulgaris (L) Hull. – Heather – flowers – Beige / rosé
Camellia sinensis (L.) Kuntze – The – leaves – Beige
Carthamus tinctorius L. – Safflower – leaves – Yellow / orange
Castanea sativa Mill. – Chestnut – bark and leaves – Beige / brown
Cetraria islandica (L.) Ach. – Iceland moss – thallus – yellow
Crocus sativus L. – Saffron – stigmas – Yellow / orange
Curcuma Longa L., 1753 – Curcuma – root – Yellow / green
Dactylopius coccus O. G. Costa, 1835 – Cochineal of carmine – insect – Red
Dracaena draco L. – Dragon tree – resin – Red / lacquer
Dysphania ambrosioides (L.) Mosyakin & Clemants – Wormseed – plant – Green / moss
Equisetum arvense L. – Horsetail – plant – Yellow / gray
Fraxinus excelsior L. – European ash – leaves and bark – Gray / dark
Galium verum L. – Ladys Bedstraw – top – Yellow
Guajacum officinale L. – Guaiacwood – wood – Yellow
Haematoxylon campechianum L.
Hedera hellx L.
Helianthus annuus L.
Hibiscus Sabdariffa D.C.
Hyperjcum perforatum L
Indigofera tinctoria L.
Indigoferai tinctoria L.
Juglans regia L.
Juniperus communis L.
Lawsonia inermis L.
Mallotus phiuppinensis M.
Matricaria chamomilla L.
Nymphea lotus L.
Papaver rhoeas L.
Populus nigra L.
Potentilla erecta Rarndel
Pterocarpus santalinus L.
Punica granatum L.
Quercus infectoria Oliv.
Quercus petraea Liebl.
Reseda luteola L.
Rhamnus catharticus L.
Rhamnus frangula L.
Rheum rhaponticum L.
Rhododendron ferrugineum L.
Rubia tinctorum Li
Rubus fruticosus L.S.L.
Rumex crispus L.
Ruta graveolens L
Sambucus nigra L.
Purpose garcinia Hanbury Hook
Sisymbrium officinale (L.)
Solidago virga Aurea L.
Spinacia oleracea L.
Tanacetum vulgare L.
Ulmus campestris L.
Urtica dioica L.
Vaccinium myrtillus L.