Corymbia ficifolia red-flowering gum

Four Corymbia ficifolia on Cedro Way show some of the range of flower color in summer. Sairus Patel, 18 Aug 2018

Typical color of Corymbia ficifolia flowers; 809 Lathrop Drive. Sairus Patel, 10 Aug 2018

Easily our most spectacular eucalypt in bloom, the flower domes at the tips of branches extend beyond the rounded leaf crown, optimally displaying their floral glory. Were these same flowers to emerge from leaf axils along the branches, much of their visual impact would be lost. The broad leaves are a glossy deep green (not the bluish-gray common in other eucalypts), notably paler beneath, and shaped like those of some tropical figs (Ficus) – whence the species name. Almost always in evidence, the woody fruit capsules or gum-nuts are instantly recognizable, often described as dice cups though more accurately akin to egg-shaped bud vases, the mouth sometimes extending slightly into an urn-like form. They are about an inch across and often hang in dense clusters that can weigh down young branches; they are a wonderful collectible and find various uses in crafts.

Corymbia ficifolia leaf and fruit. John Rawlings, Jun 2005

The genus name refers to the corymb-like clusters of flowers, technically an umbellaster, not a corymb. A recent proposal to place Corymbia species back into genus Eucalyptus has been published, though not yet widely adopted.

Professor Ron Bracewell once recalled driving along the edge of the Southern Ocean en route to Albany, Western Australia, when his wife spotted a sign for Ficifolia Road. They turned off and entered one of the three windswept coastal pockets where the species is native: a desolate stretch of beach dunes with straggly trees crouched low. In cultivation, however, it has proven immensely successful and grows to a larger size. On campus, examples can be seen on Lathrop Drive, Cedro Way, and Sonoma Terrace, all astute spots for planting since the species is sensitive to frost: cold air will slide downhill. A fine low-branching specimen is at 901 Wing Place. A large tree at 830 San Francisco Court was removed in 2021.

On campus, flower colors range from the typical vermilion and red of the species to various shades of orange, coral, and pink. White flowers are an indication of C. calophylla, a similar but taller eucalypt. Both species can have pink flowers in the wild, though rarely. Hybrids between the species exist as well, and show intermediate characteristics. Grafted cultivars that promise a specific flower color and form – many of them semi-dwarf – are available in Australia, though not in the States. They would make a worthwhile addition to our landscapes.

White-flowered examples at 823 Sonoma Terrace and 809 Lathrop Drive are likely C. calophylla. Multitrunked examples, apparently sprouting from a former stump, in the green space behind 12 Ryan Court and nearby, may also be C. calophylla, judging by their evenly tessellated bark.