Art Nouveau, better known in Catalonia as Modernism, appeared at the end of the 19th century and with its maximum expression at the beginning of the 20th century, as a reaction to classicism, and with a desire to reach all fields where its manifestation could be present, both in architecture and in interior elements, furniture, stained glass, lamps, jewellery, etc. It was also present in plastic creations, posters and in the book industry. This is an art with very specific peculiarities, a curvilinear and dynamic style with an absolute asymmetry, and it is possibly in these characteristics where the divorce with classicism is most evident. Stylisation predominated, above all, with the plant world, in which plants played a very important role, establishing a veritable allegorical repertoire. The artists of the time recovered for their creations all the symbolism that in this field, humanity, like a real treasure, has been accumulating throughout its history: Antoni Gaudí in architecture, and Alfonse Mucha in graphics, and like many others, in their works we find infinite allegories where their knowledge can bring us closer to a better understanding of this world of the artist, where nature in each of its stages was a source of inspiration for a new allegorical expression. Dried leaves in autumn were symbols of melancholy and sadness, yellow flowers were associated with solar influences, and made an allegory of glory and wealth, white lilies referred to the goddess Diana, and were attributed to honest maidens and virgins, orchids are symbols of passion and fertility, passion is the Christian allegory of the passion of Christ, the laurel is associated with victory and peace, the pomegranate with friendship and harmony, the white rose is a symbol of purity, the yellow rose is associated with friendship and joy, the red rose is attributed to Venus, the Greek goddess of love, and associated with beauty, love, and passion, in the Christian tradition it represents the blood of the martyrs and the resurrection. In architecture, when roses were placed on the ceiling of a room, they were a symbol of confidentiality of everything that was said or done inside the room, hence the Latin expression used to entrust a secret "sub rosa" (in secret).