Linum campanulatum reaches on average Template:Convert in height.<ref name=Pignatti>Pignatti S. - Flora d'Italia – Edagricole – 1982. Vol. II, pag. 22</ref> The short stem is perennial, woody and glabrous, with long herbaceous annual branches. Leaves are alternate, up to 4 cm long and 1 cm wide. The shape of lower cauline leaves is quite variable. Usually they are obovate-obtuse, but in some cases may be spatulate-lanceolate. The upper cauline leaves are gradually reduced in width to become almost linear.
The inflorescence has 3-5 campanulate actinomorphic flowers, about Template:Convert in diameter, with five free sepals and five free petals. Petals are yellow, oblong-oval, 2.5-3.5 cm long.<ref name=Pignatti/> The flowering period extends from May through June.<ref name=Pignatti/> The flowers are hermaphrodite and pollinated by insects (entomophily). Fruit is a capsule with ten compartments, each containing one seed.
This plant is widespread in the western Mediterranean, from Spain to northwestern Italy.<ref name=Pignatti/>
- Conti F., Abbate G., Alessandrini A., Blasi C., 2005 - An annotated checklist of the Italian vascular flora - Palombi Editori