Description and Characteristics of Eucalyptus
- Eucalyptus is a genus of flowering plants in the family Myrtaceae.
- Most species of Eucalyptus are trees, often mallees, and a few are shrubs.
- Eucalyptus plants have bark that is either smooth, fibrous, hard, or stringy.
- The leaves of Eucalyptus have oil glands.
- The fruit of Eucalyptus is a woody capsule commonly referred to as a gumnut.
- Eucalypts vary in size and habit from shrubs to tall trees.
- Mallees are multistemmed eucalypts that are rarely taller than 10 meters.
- Mallets are eucalypts with a single thin trunk and a steeply branching habit.
- Marlocks are shrubs or small trees with a single, short trunk and spreading, densely leafy branches.
- Eucalyptus regnans is the tallest known flowering plant on Earth.
- Eucalyptus trees have different types of bark, including stringybark, ironbark, tessellated bark, box bark, and ribbon bark.
- Mature Eucalyptus leaves are commonly lanceolate, petiolate, and waxy or glossy green.
- Seedling leaves are often opposite, sessile, and glaucous.
- Some Eucalyptus species retain the juvenile leaf form even when mature.
- Some species have shiny green leaves throughout their life cycle.
- Leaf development in Eucalyptus plants goes through four phases: seedling, juvenile, intermediate, and adult.
- Eucalyptus flowers have numerous fluffy stamens in various colors.
- The stamens are enclosed in a cap known as an operculum.
- As the stamens expand, the operculum is forced off, revealing the cup-like base of the flower.
- Eucalyptus fruits are woody capsules or gumnuts.
- Eucalyptus species have distinctive flowers and fruits that help identify them.
History and Distribution of Eucalyptus
- Eucalypts were first seen by early European explorers and collectors in 1770.
- Joseph Banks and Daniel Solander collected specimens of E. gummifera and E. platyphylla in Botany Bay.
- In 1777, David Nelson collected a eucalypt on Bruny Island in Tasmania, which was named Eucalyptus obliqua.
- James Edward Smith named several more species of Eucalyptus in the late 18th century.
- Ferdinand von Mueller's work in the 19th century contributed greatly to the understanding of eucalypts.
- Over 700 species of Eucalyptus are known.
- Some species have diverged genetically and can be recognized by specific characteristics.
- Many species appear to grade into one another, and intermediate forms are common.
- Hybrid individuals have sometimes been named as new species.
- Chemical compounds present in the leaves allow for discrimination between certain species.
- Eucalyptus is one of three similar genera commonly referred to as eucalypts.
- Many species are known as gum trees because they exude kino from breaks in the bark.
- The generic name is derived from Greek words meaning 'well' and 'to cover,' in reference to the operculum on the calyx.
- The other two related genera are Corymbia and Angophora.
- Most Eucalyptus species are native to Australia.
- A small number of species are found in adjacent areas of New Guinea and Indonesia.
- Eucalyptus deglupta ranges as far north as the Philippines.
- Eucalypts are cultivated in many parts of the world, including the Americas, Europe, Africa, and the Middle East.
- Australia is covered by 92 million hectares of eucalypt forest, comprising three-quarters of the area covered by native forest.
- The oldest definitive Eucalyptus fossils are from Patagonia in South America, dating back to the early Eocene.
- Fossil leaves also occur in the Miocene of New Zealand.
- The fossil record of Eucalyptus in Australia is scarce, suggesting its rise to dominance is a more recent phenomenon.
- The oldest reliably dated macrofossil of Eucalyptus is a 21-million-year-old tree-stump found in New South Wales.
- Extensive research has failed to uncover any Eucalyptus specimens in the Paleocene to Oligocene of South-Eastern Australia.
Tall Timber and Frost Intolerance
- Eucalyptus regnans is the tallest flowering plant, reaching a height of 100.5m (330ft).
- Coast Douglas-fir is similar in height, while coast redwood is taller.
- Six other eucalypt species exceed 80 meters in height.
- Most eucalypts are not tolerant of severe cold.
- They are usually damaged by temperatures below -5°C (23°F).
- Snow gums, such as Eucalyptus pauciflora, can withstand cold and frost down to about -20°C (-4°F).
- Subspecies E. pauciflora subsp. niphophila and E. pauciflora subsp. debeuzevillei are even hardier.
- Other species from central Tasmania, such as Eucalyptus coccifera, Eucalyptus subcrenulata, and Eucalyptus gunnii, have also produced cold-hardy forms.
Animal Relationships and Diseases on Plants
- Eucalyptus leaves contain powerful natural disinfectants and can be toxic in large quantities.
- Koalas and some possums are relatively tolerant of these compounds.
- Koalas use the smell of the leaves to make food choices.
- Eucalyptus flowers provide food for many
Eucalyptus - Wikipedia Data Sources
Reference | URL |
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Glossary | https://www.alternix.com/blogs/glossary-of-terms/eucalyptus-wikipedia |
Wikipedia | http://en.wikipedia.org/wiki/Eucalyptus |
Wikidata | https://www.wikidata.org/wiki/Q45669 |
Knowledge Graph | https://www.google.com/search?kgmid=/m/0d7gy |