Buddleja mendozensis is an extremely variable species endemic to the xeric and subxeric areas of Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

, from Jujuy to southern Mendoza

Mendoza Province

The Province of Mendoza is a province of Argentina, located in the western central part of the country in the Cuyo region. It borders to the north with San Juan, the south with La Pampa and Neuquén, the east with San Luis, and to the west with the republic of Chile; the international limit is...

 and La Pampa, where it grows on rocks at altitudes of 600 - 3,000 m. The species was first named by Gillies

John Gillies (botanist)

John Gillies, M.D. was a Scottish naval surgeon who later became an explorer and botanist, travelling extensively in South America. Educated at the University of Edinburgh, he served in the Royal Navy during the Napoleonic Wars. Afflicted by tuberculosis, Gillies left the UK aged 28 for South...

 , and described by Bentham

George Bentham

George Bentham CMG FRS was an English botanist, characterized by Duane Isely as "the premier systematic botanist of the nineteenth century".- Formative years :...

 in 1846.

Description

B. mendozensis is a dioecious

Dioecious

Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...

 shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

 0.2 - 2 m high with greyish bark. The young branches are subterete and tomentose

Tomentum

Tomentum may refer to the following:*In botany, a covering of closely matted or fine hairs on plant leaves. *A network of minute blood vessels in the brain.* Tomentum in zoology are a short, soft pubescence...

, bearing leaves of very variable shape 0.5 - 8 cm long by 0.2 - 2 cm wide, membranaceous to subcoriaceous, glabrescent

Glabrousness

Glabrousness is the technical term for an anatomically atypical lack of hair, down, or similar structures...

 to tomentose above, and densely tomentose below. The yellow to orange inflorescence

Inflorescence

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

 comprises 2 - 5 pairs of small globose heads in the axils of the terminal leaves; the corollas 3.5 - 4.5 mm long.