TREES, PLEASE! Mighty Myrtaceae – “the myrtle family”
- 3 days ago
- 3 min read
by Robin Y Rivet, for Let's Talk Plants! June 2026
Mighty Myrtaceae – “the myrtle family”
The tallest flowering tree in the world is the "giant mountain ash", which belongs to the Myrtaceae family. So does the diminutive dwarf common “myrtle”, an evergreen shrub often sold at San Diego nurseries as a tidy border plant.
What do they have in common? Most members are trees or shrubs with showy flowers featuring abundant colorful stamens, aromatic foliage, and many produce fascinating fruit. Their drought tolerance, pest resistance, and suitability to Mediterranean climates find many Myrtaceae genera thriving in San Diego County.
Although Myrtaceae is the 8th largest plant family, "trees" are not a monophyletic group, meaning they do not share a common ancestor. For example, crape myrtles have the "myrtle" name but arose from the loosestrife family, not Myrtaceae. Trees worldwide evolved similar features like woody trunks and height independently. Humans actually share about 50% of DNA with trees, but we are much closer genetically to slugs - sharing 70%. Really! Even two of the world’s tallest trees, California’s coast redwood (Sequoia sempervirens) and Australia’s giant mountain ash (Eucalyptus regnans), also share less than 50% DNA - since they lack a common ancestor.
Myrtaceae plants have long been valued for scent, flavor and medicinal values. Oil glands on leaves, stems, flowers, and anthers produce essential oils, flavonoids, and other compounds that serve ecological and defensive roles. Eucalyptus compounds often act as natural pest repellents. Crushing the leaves of the bay rum tree (Pimenta racemosa) releases a compelling, sweet-spicy fragrance. And yes, it’ll grow here. Tea tree oil (Melaleuca alternifolia) is prized for its antimicrobial, antifungal, and anti-inflammatory properties, while cloves (Syzygium aromaticum) are widely used in cooking, but clove oil also has broad pharmaceutical uses. Recent research suggests allspice (Pimenta dioica) may also have potential anti-tumor properties, possibly useful against breast and prostate cancers.
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Myrtaceae flowers are stunning. The inflorescence of Acca sellowiana (pineapple guava) is not only beautiful - but tastes sweet like candy. Eucalyptus, the most well-known Myrtaceae genus, includes over 134 species introduced into California, and more than 900 species endemic to Australia. These trees support local wildlife: hummingbirds feed on their nectar, raptors nest in their heights, and Monarch butterflies find winter shelter among them.
Myrtaceae fruits are diverse and often tasty. Jaboticaba produces fruit on its branches in a process called cauliflory. Many genera can be found growing in San Diego: tropical guava, ugni, wax jambu, Surinam cherry, pineapple guava, eugenia, strawberry guava, lemon guava, Chilean myrtle, rose apple, Java plum, lilly-pilly, grumichama, cherry of the Rio Grande, and common myrtle berries, though fresh Myrtus communis fruit can be astringent.
SPECIAL NOTICE* On June 13, 2026, the California Rare Fruit Growers of Orange County is holding its first annual Festival of Fruit since COVID incurred delays after 2019. This year it is being held at Cal State Fullerton’s campus Titan Student Union. There will be many diverse speakers (including this writer), garden tours, fruit tastings and numerous social gatherings. The theme for this year’s festival is “Eugenia and Her Sisters” a tribute to the wonderful world of Myrtaceae. Tickets are still available.
Member Robin Rivet is a ISA Certified Arborist & UCCE Master Gardener - contact her: treetutor@gmail.com
P.S. If you love Myrtaceae plants as much as I do, you might also enjoy this science-enthusiast’s you-tube video with many facts, images and intimate information about this amazing family of plants.