During the greater part of Jim Mauseth’s Intro to Botany course, students learn about the behavior and life cycles of typical plants. But for Mauseth, the high point comes when the focus shifts to the strange world of cacti. “We spend all semester teaching the kids how plants grow,” he says. “Then we go, ‘and here are the aliens!’” Welch Hall’s impressive rooftop greenhouse is filled with more than 300 species of spindly, spiky, and imposing cacti. Mauseth points out a few of the more thrilling varieties that have adapted to their harsh environments in unique ways. Fachieroa, a slender, branching, column-like cactus that reaches the ceiling, has a peculiar trick. For some unknown reason, it flowers only on one side. Mauseth says it would be like a human aging on only one side of his body. “Imagine that,” he says.



When we reach the very un-cactus-looking Welwitschia, Mauseth stops in his tracks and faces me with a proud fatherly grin. “This is an incredible mutation,” he says. This lone male specimen arrived at UT in 1975, the same year Mauseth did. Native to Southwest Africa, it’s a very odd plant that can live up to 1,500 years; few universities bother to cultivate it. From its base, which resembles a large walnut, only two leaves will ever grow. They continue to grow long and curly throughout the plant’s lifetime. Mauseth and his team have written the dates directly on the leaves to chart their progress. The base—which is unlike anything in other plants—sits exposed on top of a tall, narrow pot, and its 8-foot leaves spiral down onto the floor. Scientists are not sure what exactly the base is, but it’s not a stem and it’s not a root. If you came across a Welwitschia in the desert, Mauseth says, the base would be hidden underground. All you would see is a big pile of curly leaves sitting in the middle of endless sand.



Mauseth just acquired 25 Welwitschia seeds from the Huntington Botanical Gardens in California. The seeds are very difficult to get, and he’s hoping that several will be female.



As he shows me around the greenhouse, I notice each plant is more curious than the next. Just when you think you’ve wrapped your head around the characteristics of cacti (fat, succulent, microscopic leaves), another species shows up that completely upends the rules. It’s easy to understand how Mauseth has never tired of studying this fascinating family of plants. After all these years, he’s still a cactus guy. “Some people like orchids,” he says, “some people like roses. I like cacti.” —Dorothy Guerrero