By Katherine Wagner-Reiss

Clerodendrum trichotomum (1981-337B), fruiting by the Hillcrest Avenue fence on 10/12/19. Grown from seed collected during the 1979 Expedition to Korea and Taiwan. Photo by Katherine Wagner-Reiss.

Clerodendrum trichotomum. Flowers with a sweet scent, reminiscent of jasmine. Notable long stamens. Ovate leaves that smell like raw peanut butter when crushed. Photo by Alexander Dunkel. CC-BY-SA-2.5.

Clerodendrum trichotomun is a shrub of peak garden interest in the fall. The genus name Clerodendrum, assigned by Linnaeus in 1753, is a play on the double meaning of the Greek word kleros. First, kleros means “chance” or “fate” and refers to the risk in taking Clerodendrum-derived medicines, since reports vary widely as to their efficacy and safety! Second, kleros also means “clergy” alluding to the fact that Clerodendrum was used in the Sinhalese religion. The second half of the genus name, dendrum, derives from the Greek word for tree. Linnaeus carried the pun even further: he gave the name Clerodendrum infortunatum to the first named species and the name Clerodendrum fortunatum to a subsequent species. Yes, botanists enjoy a good inside joke!

Most Clerodendrum species are native to tropical or warm temperate areas; luckily C. trichotomum, native to N. China and Japan, is winter hardy to USDA zone 6A and survives the winters at the Morris Arboretum, which is in zone 7A. The specific epithet trichotomum means branching into three, referring to the inflorescences (flower clusters) and infructescences (fruit clusters), which are both long-peduncled three-branched cymes.

The common name Harlequin Glorybower implies a parti-colored feature and a glorious bower, and Clerodendrum trichotomum delivers on both counts with its showy flowers and magnificent fruits: bright blue drupes surrounded by red calyces. Another common name is peanut butter tree; the crushed leaves smell like raw peanut butter.

While this beauty does not supply fall foliage color, it begins to display sweet-smelling white flowers in late summer, followed by iridescent fruits in fall. The shrub is easy to find because it is close to the Springhouse, a feature on the Morris Arboretum map. The Springhouse, originally used to keep perishables cool, was restored in 2004 and is one of the few remaining examples of a springhouse in Philadelphia. See the mapped location of Clerodendrum trichotomum and the Springhouse at Collection Connection

According to Tony Aiello, curator and director of horticulture at the Arboretum, for the past year or so he has become concerned about Clerodendrum as a potential invasive because they are finding it popping up around the Arboretum, often at some distance from the parent plant. So, while the fruits are attractive to us, apparently the birds like them as well. Based on its unexpected occurrences, the Arboretum staff have been thinking of removing the large mass next to the Springhouse. As with other non-native plants at the Morris, the staff are always vigilant for plants that wander around, trying to keep the proverbial horse in the barn.
Katherine has her Certificate in Botany from the New York Botanical Garden and is a botanical tour guide and free-lance writer.

Infructescence, which shows obvious three-part branching explaining the specific epithet trichotomum: branching into three. Inedible metallic-blue fruits appeal to some birds. Photo by Katherine Wagner-Reiss.

View of the Springhouse complex when standing by the Clerodendrum trichotomum. The only existing Morris Arboretum structure that predates the Morrises living on the property. Photo by Katherine Wagner-Reiss.