The UA's Main Library is a mini-arboretum in itself. Warren Jones planted many of his experimental species around this building, after is completion in 1977. Here's a brief "plant walk" around three sides of the Main Library. Evenings in late April through June are a good time to see flowers. At that time of the day, most of the walk will be in shade.

Start at the NE corner, at the intersection of Cherry Ave and the Main Mall. Proceed southward on the eastern side of the building.

The small spreading trees with 6” gray leaves are Loquat - Eriobotrya japonica. Edible fruit from the Far East. Related to apples and roses. Needs afternoon shade and adequate water in summer.

The trees with large glossy leaves and white flowers are Southern magnolia - Magnolia grandiflora. Needs afternoon shade here. See larger ones on the east side of the State Museum.

Trees with small gray leaves are Olive - Olea europaea. Native to Mediterranean. Edible fruit. Oldest olives on campus are in the historic district next to the Park Avenue Main Gate. Good shade tree for Tucson, but may causes allergic problems.

A new tree just planted near the sidewalk is Gingko - Gingko biloba. Native to China. This is a very old species that has been able to survive through climate changes and human destruction. Related to pines and other cone bearing plants. Not a good choice for a hot spot, but OK with afternoon shade.

In the lawn area are many Southern Live Oaks - Quercus virginiana. Native to the eastern part of US. Often used as a landscape tree in Tucson, but rarely given the room required. Oaks hybridize freely, making identification tricky.

Up against the walkway, is a small garden with several tropical shrubs and small trees. The largest tree, toward the northern edge is Senna spectabilis excelsa (no common name). Showers of bright yellow flowers in June. From Argentina. Related to mesquites and palo verdes.

Look east (left) across Cherry Avenue. The huge mesquite at the corner of the parking garage might be the broadest on campus. It is a hybrid with apparently at least one South American parent. Notice the size to which mesquites are capable of spreading.

Turn the corner to continue westward along 4th Street. Just inside a small niche after the corner is a strange tree with glossy leaflets shaped like a cross. It is Calabash tree - Crescentia alata. From southern Mexico. Related to our Desert Willow. Brown flowers grow directly on the trunk. Designated a Great Tree of Arizona.

Next we see a very full tree with rubbery leaves, completely crammed into its slot next to the building. This is Port Jackson Fig - Ficus rubiginosa. Native to Australia, but spreading in the south Pacific.

The lacy-leaved trees with blue blossoms overhead are Jacranda mimosifolia, but a special variety sent to Warren Jones from high elevations in South America. These trees bloom both spring and fall, and are very frost resistant. Note that there are 3 on this south side of the Library.

Continuing westward.... The tall tree up next to the building, behind a wall is Guaimuchil or Pithecellobium dulce. Native to the Mexican tropics, it is tender here, normally having some die back each cold winter.

Beyond the parking lot, turn the corner to walk on the Library’s west side.

The green-trunked tree in the corner at the top of the lawn area is a Rock Fig, or Ficus petiolaris. Native to southern Mexico and Baja California. Normally found only in stream beds where the invasive roots search out water. Perfectly suited to the top of a hill facing southwest. Suffers from freeze damage on coldest nights. A UA Campus Arboretum Heritage Tree, adopted by Tom Sanders in honor of his parents.

Proceeding northward, the small trees in the planter to your right are Crape Myrtle - Lagaerstroemia indica. A good tropical looking patio sized tree for Tucson. Deciduous. Bright pink flowers. Native to China.

Closer to the building in the next planter to the north are Texas persimmons - Diospyros texanum. Small multi-trunked shrubs/trees. Fruit is loved by birds.

Last interesting trees on this walk are on your left ahead. These small Ghost Gums - Eucalyptus papuana - were planted by 4th Graders from the Blenman Elm School as part of a National Geographic Educational Grant in which they learned about Australia.

The front of the Main Library has palms and smaller trees. But it is a hot place, and we will do that walk in the winter.

Director - Elizabeth Davison
UA Campus Arboretum - University of Arizona
PO Box 210036 - Tucson AZ, 85721
Telephone: 520-621-7074

Last Updated: 12 May 2008