As befitting a campus that is also a designated arboretum, Rice employs a team of 31 groundskeepers, arborists and other specialists who develop and maintain approximately 4,500 trees across its 300 acres. One of those arborists, Dawn Roth-Ehlinger, led a group of Rice students and staff on a lively walk to talk trees Nov. 5.
While the national Arbor Day holiday is in April, Texas Arbor Day is in November. This is coincidentally the best time to plant and prune trees in Texas, Roth-Ehlinger said. One of the trees visited on the walk was just planted, in fact — an acacia, only the second one on campus, in the courtyard between the Anderson Biological Lab and the Keith-Wiess Geological Lab.
The young acacia tree is near another unusual specimen on campus: Quercus suber, or the cork oak, is the only one of its kind at Rice, with a rough, bark-covered trunk that reveals the telltale soft, hollow feel and sound of cork when touched.
Although 50% of the canopy at Rice is live oak trees and another 15% various other oak specimens, Roth-Ehlinger said the grounds crew is working hard to ensure more biodiversity on campus in the event of a fungal disease or blight like oak wilt. That means planting more trees like the Mexican plum trees (Prunus mexicana) outside the Rice Memorial Center that produce vibrant purple-pink fruit and flowers, or the hardy yaupon holly (Ilex vomitoria).
Yaupon berries are toxic to humans, as the Latin name of the tree implies, said Roth-Ehlinger — but not the leaves. Those can be dried and brewed into a tea, and are the only naturally occurring source of caffeine in North America.
As climate change continues to threaten coffee-growing regions across the world, Roth-Ehlinger said, don’t be surprised if future generations turn to the yaupon tree for their caffeine fix. Could a Rice-grown-and-brewed beverage be in our future?