Of interest this week at Beal...

Buffalobur rostratum Family: the Tomato family, Also called Colorado bur, Kansas thistle, Texas thistle, W. J. Beal Mexican thistle, buffalobur nightshade Botanical Garden The buffalobur, Solanum rostratum, is a native American in the tomato family whose natural range extends from the northern Great Plains to central Mexico. Its name refers to its signature habitat in the edges of mud wallows frequented by the American bison, Bison bison. It is an occasional contaminant of hay or and can be found in the central Midwest, although it is much more common in the western portion of its range. Since its can be overlooked in a seed packet, they have been inadvertently introduced to many parts of the world outside its native range, including Russia and Australia.

It can grow to a height of 2 feet (approximately 60 cm), is branched to a bushy habit, and is completely covered with sharp, needle-like yellow spines. For folks living within its range, it poses an irritation to anyone walking outdoors, or maintaining furry pets. For anyone raising sheep, it presents a continuous threat in the loss of wool value of a bur- contaminated coat. But it is this characteristic that made its dispersal so effective while occupying the shaggy coats of bison that carried it long distances. It has been declared a noxious weed in most states where it is common.

Buffalobur is considered to be the original host plant in the formerly wild range of the Colorado beetle, Leptinotarsa decemlineata. The insect was unknown to the indigenous peoples of the Andes, where the potato was domesticated. But after the potato, Solanum tuberosum, was introduced to western North America, the beetles took advantage of their discovery.

Buffalobur leaves are toxic to humans and cattle, largely because of the presence of two forms of the basic tomato family alkaloid solanine (Dewick, 1977).

In observing the of buffalobur, one sees a feature not ubiquitous in the tomato family, bilaterally symmetry, at least in the gross morphology of the calyx and corolla. When one looks closer at the disposition of the style, it reveals that individual produce The seeds of buffalobur are produced inside of these extremely spiny . The spines were instrumental in utilizing the Ameri- can bison, colloquially called buffalo, to disperse the and their included seeds. In the modern world, it is these burs that are the most damaging and irritating. When lodged on a sheep, they greatly degrade the value of the wool.

flowers that may be either right- or left-handed (dynamic enantiostyly). The below shows its style to be inclined toward the right side of the corolla. In 2002, Jesson and Barrett (Nature Vol. 417) showed that plants with dynamic enantiostyly (both handedness forms on the same plant), when compared to plants with monomorphic enantiostyly (plant populations with each style handedness the same for each flower on an individual plant) and plants manipulated to have straight styles, showed that the dynamic enantiostyly equipped plants had the highest rates of outcrossing, and therefore the highest potential for genetic diversity.