''Baccharis linearis'', the romerillo or Chilean little rosemary, is a common

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

in Central

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

. It is frequently found in old field after agriculture. Cecidia or galls caused by the fruit fly ''Rachiptera limbata'' grow as white, spongy and globose tissues on the

twig A twig is a thin, often short, branch of a tree or bush. The buds on the twig are an important diagnostic characteristic, as are the abscission scars where the leaves have fallen away. The color, texture, and patterning of the twig bark are ...

s of the plant.

Description

This densely branched, shrubby species reaches heights of 1-3 m. The branches are erect. Young branches have a green bark, which becomes reddish brown with age. The linear, sessile, rarely dentate leaves are 0-30 mm long and 0-2.5 mm wide. Dentate leaves are observed on young plants, but this characteristic is lost in later ontogenic stages, in which only linear leaves devoid of any dentation are formed. The capitula are formed in groups. In male plants they are 3-4.5 mm wide and in female plants they are 2-3 mm wide. They are attached to the branches by 3-8 mm long peduncles.

Natural hybridisation

This species is part of a homoploid hybrid swarm involving ''

Baccharis macraei ''Baccharis macraei'' is a species of shrub native to Chile and Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_ ...

''. Together both parent species form the natural hybrid ''

Baccharis intermedia ''Baccharis intermedia'' is a species of shrub native to Chile. The species was first formally described by the botanist Augustin Pyramus de Candolle in 1836. Distribution This species is common on coastal hills of central Chile. Natural hybri ...

''.

References

linearis Plants described in 1798 Flora of Chile Dioecious plants {{Astereae-stub