ARTHUR C. GIBSON, MEMBG Director
Does UCLA have bragging rights for nurturing the tallest living angiosperm in the United States?
One statement made earlier needs to be verified and carefully understood. A MEMBG specimen of Eucalyptus grandis (rose gum or flooded gum) is, we suspect, the tallest angiosperm presently growing in the United States. If we are going to make such a claim, consider what this means. The California Register of Big Trees recorded our plant, measured in April 1996, as 175 feet in height with a girth at 4.5 feet of 136 inches but a crown of only 43 feet, for 322 points. It has continued to grow upward and needs a new measurement, for anyone who wants to (responsibly) try.
Tallest. We are not saying the biggest or largest. The National Register of Big Trees (americanforests.org/resources/bigtrees/) and all state registers recognize the most massive trees, i.e., they have the most standing biomass, board feet, etc. Therefore, a plant with a huge base may earn a higher point score than a taller specimen. For example, many oaks with massive trunks rank higher in the national and California registers. Several specimen bluegum eucalypts in California have girths exceeding 400 inches, but in the California Register our specimen was listed as the tallest of the genus, and therefore the tallest hardwood tree in the Golden State. The world's tallest angiosperm tree is Eucalyptus regnans in wet forests of Tasmania.
Living. There are some guestimations in the literature about trees in the United States up to 200 feet in height. Moreover, many millions of years ago there was tropical rain forest in southern regions. Lowland tropical forests, such as in southern Mexico and Central America, today have towering emergents that can reach 200 feet, such as big figs (Ficus) and kapok (Ceiba pentandra). Let's keep our claims to the here and now.
Angiosperm. Angiosperms are the flowering plants, including dicotyledons and monocotyledons. Only a few monocotyledons, certain palms, ever exceed 120 feet in height, so there is no competition there. We are not including all plants, because there are many gymnosperms, specifically conifers, that grow much taller in California. The tallest coast redwood (Sequoia sempervirens), in Humboldt Redwood State Park, is more than 360 feet in height. Nonetheless, it would be pleasing that California has the tallest living gymnosperm and angiosperm in the country.
United States. We can add Canada but not claim North America. An earth scientist would inform you that North America extends to Oaxaca in southern Mexico; some tack on Central America. Repeating, the American tropics have some dicotyledonous giants that might dwarf our rose gum.
The National Register tells us that the tallest native hardwoods rarely reach 130 feet, and there are only a few records above 160, notably yellow poplars (Liriodendron tulipifera) of eastern North America. One certainly does not expect giants in deserts or the plains states, or, for that matter, anywhere that can be ravaged by hurricanes (the East Coast) or tornados (Tornado Alley). At home in Westwood, there is no violence except for an occasional earthquake. Our chief competition in California may be some unregistered giant lurking in Northern California.