PLANTA DEL MES – JUNY 2025
CAT: trepó, blatària, llepassera borda, herba de les arnes
ES: Gordolobo, polillera, sabonera…
FAMILY: Scrophulariaceae
Synonyms:
- Blattaria vulgaris Fourr.
- Thapsus blattaria (L.) Raf.
- Verbascum blattaria var. normalis Kuntze
- Verbascum luridum Salisb.
- Verbascum carduifolium Hayek
- Verbascum rhinanthifolium Davidov
- Verbascum blattaria L. subsp. blattaria
- Verbascum blattaria subsp. repandum (Willd.) Bornm.
DISTRIBUTION: Native from Northern Europe to Afghanistan and Northwest Africa. In the Balearic Islands, it is known from four populations in Mallorca: Lluc, Sóller, Esporles, and S’Albufera (where only one individual has been observed). It has also become naturalized in other parts of the world.
CONSERVATION STATUS: Although it does not have legal protection due to its relatively broad global distribution, it is classified as vulnerable (VU) according to the 2017 Red Book of Vascular Flora of the Balearic Islands.
PHENOLOGY: Flowers from June to September.
LIFE FORM: Biennial plant. In its first year, it forms a basal rosette; in the second year, it produces flowering stems and sets fruit. It may occasionally behave as an annual species.
HABITAT: Sunny areas with well-drained soils, humid meadows in forest clearings, woodland edges, and path margins.
Verbascum blattaria is a rare biennial plant in the Balearic Islands. It has been present in the Botanic Garden since its early days, thanks to seed collection carried out at the Coll de Sóller in 1985 by the local botanist Jeroni Orell Casasnovas. Since then, the species reappears each year in the Garden, almost spontaneously, choosing where it wants to grow. It blooms from June and produces thousands of tiny seeds—1,000 of which weigh no more than 0.1 grams. It is a striking plant and, due to its rarity in the Islands, enjoys the unique privilege of establishing itself every two years in different corners of the Botanic Garden.
Known as blatària in Catalan or moth mullein in English (literally “cockroach mullein” from Spanish gordolobo polillero), it originates from Eurasia and North Africa and has been introduced in various regions around the world. It can grow up to 1.2 meters tall and is characterized by completely hairless basal leaves and lower stem. The flowers are solitary on each bract, showy and yellow, with five dimorphic stamens: some have purple hairs on the upper third, while others have purplish hairs on the lower two-thirds—features that help distinguish it from other Verbascum species. When it fruits, it forms a round capsule containing many small, rough seeds.
Studies on its metabolic compounds have identified 17 secondary metabolites. The plant extract shows antioxidant activity, suggesting significant potential health benefits. In fact, the species name blattaria comes from the Latin word blatta (cockroach), as the plant was once believed to repel cockroaches and other insects.
Other Verbascum species, locally known in the Balearic Islands as trepons, can also be found. They are distinguishable by their basal leaves, flower arrangement, and calyx shape, though hybrid forms with intermediate traits may occasionally appear.
