Two large Northern Catalpa trees (also known as Indian Bean Tree or Cigar Tree) can be seen along Arboretum Drive near the Juniper Collection. The genus name Catalpa purportedly comes from a Cherokee Indian word for "bean tree" - the dark brown seed pods that become conspicuous in mid- to late summer have a long (8-20 in.), bean-like shape. The showy white, bell-shaped flowers highlighted with yellow and purple markings in the center appear in late May. Northern Catalpa grows to heights of 40-70 ft. Its large (6-12 in. long), heart-shaped leaves are rounded to cordate at the base and pointed at the tip.

Catalpa belongs to the Bignoniacea family, which also includes Cross Vine and Trumpet Creeper. The natural range for Northern Catalpa includes western Tennessee and other parts of the Central Mississippi Valley. It has been widely planted in urban areas as an ornamental and shade tree. The brittle wood resists rot and in the past has been used for railroad ties, fence posts, etc.

An attractive tree in the Shade Tree Collection is Siebold Ash, a native of China, South Korea, and Japan. It is a relatively small tree growing to heights of 20-30 ft. Siebold Ash is one of the few ash species that has fragrant, showy flowers with a corolla composed of linear white to cream petals. It bears both bisexual (perfect) and unisexual (imperfect) flowers in the spring. A member of the Olive Family (Oleaceae), Siebold Ash is one of about 65 species in the genus Fraxinus. As with other ash species, this tree has opposite, pinnately compound leaves with 5-7 leaflets. The dark green leaves turn an attractive red/purple in the fall. The fruit (a samara - a simple dry, winged fruit) matures in the fall and is tinged with purple. The wood is used in Asia to make high quality furniture and wood utensils.

April and May are prime times to see Viburnums in bloom. The UT Arboretum Society has recently enhanced the Arboretum's Viburnum collection with 67 new plants including 20 species and 38 forms. These are planted along Valley Road between the gate and the Dwarf and Unusual Conifer Collection. As these shrubs develop, they will provide a beautiful spring display and provide visitors an opportunity to observe some of the diversity available with these popular landscape plants.

Two examples of our established Viburnums were in bloom near the Visitors Center towards the end of April and beginning of May.

Leatherleaf Viburnum (Viburnum rhytidophyllum) is one of the earliest shrubs to bloom in the spring. Its opposite, evergreen leaves are dark green and have a leathery texture. The fragrant, creamy white flowers are borne in dense terminal clusters (cymes). The fruits are initially red, but become black as they mature. The shrubs sucker readily and grow to heights of 15 ft or more.

Two Chinese Snowball Bush Viburnums (Viburnum macrocephalum) near the front of the Visitors Center have brilliant, globose clusters of sterile, white flowers that are a beautiful lime green when they first emerge. This species is a native of China, and the sterile form is only known from cultivation; the wild form has both sterile and fertile flowers. It grows to heights of 12-20 ft.

Viburnums were historically classified by botanists as belonging to the Caprifoliaceae (the Honeysuckle family), but recent morphological and biochemical studies have caused them to be reclassified to the Adoxaceae, a family which also includes Elderberries (Sambucus).

View a list of Previously Featured Plants