Other Wild Resources
Dye plants, thistle, caper and fennel, among others, are examples of high potential Wild Resources which are currently under exploited.
Dye Plants
Dye plants are plants that produce natural dyes, which can be extracted from different parts of the plants. In some plants, the dye comes from the leaves, while in others from the flowers, trunks, roots, seeds or fruits. Dyes can be extracted through various physical-chemical processes, such as maceration, distillation, fermentation, decantation, precipitation, filtration, etc. Some fibres can be dyed directly with natural products, such as wool or silk, for example. Others, like cotton, require an animal molecule in the dye. Several colours can be produced from different plants:
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Yellow (e.g. saffron crocus (Crocus sativus L.), sourgrass, dyer’s chamomile (Anthemis tinctoria), dyer's greenweed (Genista tinctoria), dyer's weed (Reseda luteola L.), etc.);
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Red (e.g. Indian madder (Rubia cordifolia L.), dyer's madder (Rubia tinctorum L.), safflower (Carthamus tinctorius L.), Roccella tinctoria DC, pomegranate, etc.);
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Green (e.g. horsetail, spinach, laurel, walnut tree, etc.);
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Blue (e.g. true indigo (Indigofera tinctoria), dyer's woad (Isatis tinctoria L.), etc.);
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Violet (e.g. lichen (Roccella tinctoria DC), common hollyhock (Alcea rosea), etc.);
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Browns and blacks (e.g. henna (Lawsonia inermis), common walnut, acacia (Acacia catechu), tanner's sumach (Rhus coriaria), etc.).
Thistle
Thistle (Cynara cardunculus L.) belongs to the Asteraceae family, which includes the wild thistle variants (C. sylvestris (Lamk) Fiori), the artichoke (C. scolymus (L.) Fiori) and the cultivated thistle (C. altilis DC.). It is a species that grows naturally in areas of pasture, uncultivated, fallow and cleared land, having adjusted to extreme habitat conditions, that is, high temperatures and water stress in the summer, dry, rocky and uncultivated soils.
Flowering occurs in June and July. Dried thistle flowers provide the enzymes (cardosines) responsible for the clotting of sheep's milk that is the basis of several Portuguese regional cheeses with Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI), such as "Serra da Estrela", "Azeitão", "Serpa", "Nisa", among others. In addition to its traditional use as a clotting agent in the manufacture of sheep's milk cheese, it can also be used in the production of biodiesel (through the pressing of the seeds) or heat energy (by burning biomass), and its natural extracts can be used medicinally.
Main uses:
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Cultivated thistle: biomass (plant), milk rennet (flower), oil and biodiesel (seeds);
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Artichoke: cooking (fleshy bracts), décor (plant);
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Wild thistle: milk rennet (flower);
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Wild and cultivated thistle, artichoke: use of compounds in herbal medicine (leaves, stems and flowers).
Its economic return varies, depending on which part of the plants are used and to what end. If different applications are combined, the economic return will be higher.
Fennel
Fennel (Foeniculum vulgare Mill.), also known in Portugal as fiolho or erva-doce, belongs to the Apiaceae family. It is a perennial plant, from the Mediterranean region, which spontaneously colonizes wasteland and uncultivated land in dry places, growing to great density over large patches. It also occurs in clearings of degraded bush, roadsides and croplands. The necessary environmental condition for its survival is good sun exposure, as it adjusts to both humid and dry environments. It blooms in May-June and propagates through sowing. Its aerial section has an aniseed aroma and a tangy and bitter taste.
Main uses:
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Medicinal use: it can be used as syrup or infusion. It has mucolytic (syrup), antiseptic, antispasmodic and digestive (infusion) action. The leaves have local antiseptic healing action, and the root has a diuretic effect;
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Culinary use: the stem and flowers are edible, in salads and soups. The seeds are used to flavour cakes and in bakery and pastry by-products. It is a domesticated species, cultivated as a vegetable;
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Other uses: used as dye, flavouring for pharmaceutical products and in perfumery.
