Árnica: a multivariate analysis of the botany and ethnopharmacology of a medicinal plant complex in the Iberian Peninsula and the Balearic Islands.

BACKGROUND

Medicinal plant complexes of different species sharing vernacular names, morphological and aromatic characteristics and uses are common in traditional medicine of different cultures. A quantitative methodology as a tool for ethnopharmacological studies is presented for systematically analyzing morphological and therapeutic features shared by several species integrating such complexes.

OBJECTIVE

The aim of this paper is to apply a novel methodology to determine whether complexes are homogeneous and species within the complexes are completely interchangeable or not. Moreover, to find out if those species giving the name to the complex are also those which provide a large number of complex descriptors. For this purpose we study the complex of medicinal plant species which share the vernacular name "Árnica" in the Iberian Peninsula and the Balearic Islands, through the systematic recording of past and current local therapeutic uses and administration forms, plant-parts and localities where the different species are used. Being a newly introduced name in the region, "Árnica" offers an interesting field to study the genesis and dynamics of ethnopharmacological categories and medicinal plant complexes.

METHODS

A systematic review of the botanical, ethnobotanical and ethnopharmacological literature from 1895 to 2010 and of databases was performed in order to obtain information on the use of plants locally named as "Árnica" or with binomials that include the word "Árnica", in the Iberian Peninsula and the Balearic Islands.

RESULTS

The "Árnica" complex includes 32 different plant species in the Iberian Peninsula, belonging to six families of Angiosperms, which partially share morphological characteristics and therapeutic properties. These are some of the most popular medicinal species of the Iberian Peninsula and are mainly used to treat inflammation, wounds, hematoma, and contusion. The vegetal materials are primarily macerated or decocted, and the methods of administration are plasters, washes, frictions or direct application of the plant.

CONCLUSIONS

Medicinal plant complexes are frequent in ethnopharmacological contexts and require being clearly detected, and systematically studied. Plant species within each complex are only partly interchangeable because the sharing of characters, including medicinal uses, is low. "Árnica" medicinal plant complex is extremely dynamic in the Iberian Peninsula. In less than two hundred years up to 32 different plant species belonging to six different plant families became labeled "Árnica". Medical staff was extremely influential in the adoption of "Árnica" as a vernacular name between 1785 and 1864 in Spain and Portugal but not in the repertory of uses adopted for the plants within the complex. In terms of total descriptors shared in the complex, Arnica montana L. is less relevant than other three species, belonging to the Inuleae Cass. tribe, of the Asteraceae (Chiliadenus glutinosus (L.) Fourr., Inula montana L. and Dittrichia viscosa (L.) Greuter). Thus "Árnica" complex is labeled by three different Inuleae Cass. species and receives the name from a fourth Madieae Jeps. species (Arnica montana L.).