Buddleja perfoliata is endemic to the xerophytic and subzerophytic grasslands of central Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 at elevations of 1500 – 2700 m. The species was first named and described by Kunth

Carl Sigismund Kunth

Carl Sigismund Kunth , also Karl Sigismund Kunth or anglicized as Charles Sigismund Kunth, was a German botanist...

 in 1818.

Description

B. perfoliata is a small 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 0.8 - 2 m tall in the wild, much branched, and with a greyish-black shredding bark. The young branches are subquadrangular and tomentose

Tomentose

Tomentose is a term used to describe plant hairs that are flattened and matted, forming a woolly coating known as tomentum. Often the hairs are silver or gray-colored...

, bearing sessile

Sessility (botany)

In botany, sessility is a characteristic of plants whose flowers or leaves are borne directly from the stem or peduncle, and thus lack a petiole or pedicel...

 lanceolate to elliptic

Leaf shape

In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...

 opposite subcoriaceous leaves, rugose

Rugose

Rugose means "wrinkled". It may refer to:*Idiosoma nigrum, more commonly, a black rugose trapdoor spider*Rugosa, an extinct order of coral, whose rugose shape earned it the name...

 above with dense felt-like tomentum

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...

 covering both surfaces. The yellow inflorescences, redolent of sage, are 5 - 25 cm long, comprising 5 - 26 pairs of heads borne in the axils of the leaves, each head about 1 cm in diameter with 30 - 40 flowers.