Eucalyptus camaldulensis. RIVER RED GUM. Australia
River red gum, one of the eucalypts most commonly seen
in California, grows along rivers over most of Australia,
MYRTACEAE (Myrtle family)
Red gums were planted as an avenue on Searsville Road and in scattered locations. Other old specimens can be seen across Galvez Street from the football stadium. Meanwhile, river red gum continues to be a popular choice for new planting on dry sites, for example on the west side of Campus Drive East between Serra Street and Escondido Road, where it has been under serious attack by the lerp insect, a species of psyllid.
Buds in sevens, with conical opercula, can always be found, though sometimes there are as many as 11. In case of doubt, look for juvenile leaves; while not so very different in shape from the mature leaves (a little shorter and broader), the juvenile leaves are distinctly bluish and identify campus red gums at a glance. The papery opercula, pushed off by the growing flowers, fall on the ground, sometimes with the sound of light rain. The benign litter soon blows away. If you are observant and catch the flower buds as they are developing you can find a tiny second operculum. Just as the operculum represents the fused petals of an ancestral plant, so the outer operculum represents the bracts that surrounded those petals. When the eucalypts long ago dispensed with petals as an attractant to pollinators, economically relying on the sex organs alone for color, the operculum was assigned the role of covering the delicate growing stamens. Hence the name eucalyptus, meaning well covered. The name of the nymph Calypso (unconfirmed daughter of Atlas), who troubled Odysseus, has the same Greek origin.
Operculum in Latin means lid, the same word that is used for the hard trapdoors that protect small marine molluscs and are found on beaches as white discs with spiral engraving.
Other campus Eucalypts
E. acaciiformis | E. aggregata | E. albens | E. albida | E. blakelyi | E. botryoides | E. botryoides hybrid | E. bridgesiana | E. caesia | E. camaldulensis | E. cinerea | E. citriodora | E. cladocalyx | E. conferruminata | E. cornuta | E. crebra | E. cypellocarpa | E. diversicolor | E. dundasii | E. dwyeri | E. erythronema | E. ficifolia | E. globulus | E. goniocalyx | E. gunnii | E. intertexta | E. kruseana | E. laeliae | E. lehmannii | E. leucoxylon | E. linearis | E. loxophleba | E. macarthurii | E. macrandra | E. maculosa | E. mannifera | E. megacornuta | E. melliodora | E. morrisbyi | E. nicholii | Eucalyptus Notes | E. ochrophloia | E. oleosa ssp. oleosa | E. paniculata | E. parvifolia | E. parvula | E. patens | E. pauciflora | E. pellita | E. platypus | E. polyanthemos | E. pulchella | E. pulverulenta | E. punctata | E. redunca | E. resinifera | E. robusta | E. rudis | E. salubris | E. sideroxylon | E. squamosa | E. stellulata | E. urnigera | E. viminalis | E. viridis
Illustrations: Bud and capsule illustration from Australia Forestry and Timber Bureau, Illustrations of the buds and fruits of eucalyptus species, with an alphabetical index, covering 486 species and varieties, 4th ed., Canberra, 1962 | BudsAdditions/Revisions:
Name derivation, genus | species: well covered | congregation of monk hermits founded a thousand years ago in Tuscany at CamaldoliRelated material: Eucalyptus checklist