March06_2010

Botanical Glossary - Home - References Cited

The Tasmanian Blue Gum, Southern Blue Gum or Blue Gum, (Eucalyptus globulus) is an evergreen tree, one of the most widely cultivated trees native to Australia. They typically grow from 30 to 55 m (98 to 180 ft) tall. The tallest currently known specimen in Tasmania is 90.7 m tall. There are historical claims of even taller trees, the tallest being 101 m (330 ft). The natural distribution of the species includes Tasmania and southern Victoria (particularly the Otway Ranges and southern Gippsland). There are also isolated occurrences on King Island and Flinders Island in Bass Strait and on the summit of the You Yangs near Geelong. There are naturalized non-native occurrences in southern Europe (Galicia and Portugal), southern Africa, New Zealand, western United States (California), Hawaii and Macaronesia.

The d'Entrecasteaux expedition made immediate use of the species when they discovered it, the timber was used to improve their oared boats. The Tasmanian Blue Gum was proclaimed as the floral emblem of Tasmania on 27 November 1962. The species name is from the Latin globulus, a little button, referring to the shape of the operculum.

The bark shreds often, peeling in large strips. The broad juvenile leaves are borne in opposite pairs on square stems. They are about 6 to 15 cm long and covered with a blue-grey, waxy bloom, which is the origin of the common name "blue gum". The mature leaves are narrow, sickle-shaped and dark shining green. They are arranged alternately on rounded stems and range from 15 to 35 cm in length. The buds are top-shaped, ribbed and warty and have a flattened operculum (cap on the flower bud) bearing a central knob. The cream-colored flowers are borne singly in the leaf axils and produce copious nectar that yields a strongly flavored honey. The fruits are woody and range from 1.5 to 2.5 cm in diameter. Numerous small seeds are shed through valves (numbering between 3 and 6 per fruit) which open on the top of the fruit. It produces roots throughout the soil profile, rooting several feet deep in some soils. They do not form taproots.

The plant was first described by the French botanist Jacques Labillardière in his publications Relation du Voyage à la Recherche de la Pérouse (1800) and Novae Hollandiae Plantarum Specimen (1804). The author collected specimens at Recherche Bay during the d'Entrecasteaux expedition in 1792.

Blue gum is one of the most extensively planted eucalypts. Its rapid growth and adaptability to a range of conditions is responsible for its popularity. It is especially well-suited to countries with a Mediterranean-type climate, but also grows well in high altitudes in the tropics.

Blue gums have historically been used as street trees but are now regarded as unsuitable by many municipalities due to their rapid growth and mature size.
Blue gum timber is yellow-brown, fairly heavy, with an interlocked grain, and is difficult to season. It comprises 65% of all plantation hardwood in Australia with approximately 4,500 km² planted. The tree is widely cultivated elsewhere in the world. It is primarily planted as a pulpwood, and also as an important fuelwood in many countries. It has poor lumber qualities due to growth stress problems, but can be used in construction, fence posts and poles.
The leaves are steam distilled to extract eucalyptus oil. E.globulus is the primary source of global eucalyptus oil production, with China being the largest commercial producer The oil has therapeutic, perfumery, flavoring, antimicrobial and biopesticide properties. Oil yield ranges from 1.0-2.4% (fresh weight), with cineole being the major isolate. E.globulus oil has established itself internationally because it is virtually phellandrene free, a necessary characteristic for internal pharmaceutical use. In 1870, Cloez, identified and ascribed the name "eucalyptol" — now more often called cineole — to the dominant portion of E. globulus oil.

It was introduced to California in the mid 1800s, partly in response to the Southern Pacific Railroad's need for timber to make railroad ties, and is prominent in many parks in San Francisco and throughout the state. Naturalists, ecologists, and the United States National Park Service consider it an invasive species due to its ability to quickly spread and displace native plant communities, while local authorities, especially many fire departments across California consider them to be a major fire hazard. Although, the United States Department of Agriculture does not list it among is Invasive and Noxious plants list in California. Due to such reasons, programs across the state of California have been taken to remove all eucalyptus growth and restore native biomes in some park areas, such as on Angel Island in San Francisco Bay, and in the Hills of Oakland California, where Eucalyptus Trees helped fuel the 1991 Oakland Hills Firestorm.

Photos - This tree is at least 75 feet tall, growing outside the Pe Mex gas station on Highway 190 at the edge of Oaxaca City. Its name is Eucalyptus Globulus (Blue Gum) see above notes from Wikipedia for an explanation.

Photos - The Zocalo is always a happening place - at ay given day there are many colorful vendors such as the helium balloon vendor (frame left) and lots of folks enjoying a bit of rest and relaxation. The children in frame right are sitting on the stone steps leading to the gazebo, enjoying an ice-cream treat.

Center frame: One of many weed like plants that can be seen nearby the Zocalo is this Leonotis Nepetifolia (Lion's Tail) Native of tropical Africa, and found throughout the tropics. It is often found at roadsides and overgrown pastures. It is a single stemmed, erect herbaceous annual, growing about 90 cm tall. The stem has four sides. The distinctive feature is the thistle-like inflorescence, which is often used in dried flower arrangements. The flowers are orange. The leaves can be boiled as a tea for fevers or as a bath for prickly heat. In Barbados, it was used with other plants for worms and tuberculosis, in Trinidad, the tea was used for 'flu.

Leonotis leonurus which has come into southern California under the name of "lion's tail" also nicknamed 'dagga' (familiar term for cannabis sativa). From the leaves of this member of the mint family, a dark resinous exudate is extracted and smoked like tobacco or as a tobacco additive. The Hottentots are quite fond of it as a narcotic which produces a mild state of euphoria. It is also used for subcutaneous diseases such as leprosy. Europeans living in Transvaal area know the plant as 'drug lionsear' and use a decoction of the flowering tips in treating cardiac asthma and epilepsy.

Photos - L-R - A elderly couple relaxes on a bench and watches the world go by.

The Gazebo or band stage is a popular place to relax: one can purchase treats from the refreshment stand, which is more like a small grocery store, during regular day time hours then relax in the shade and comfort of the gazebo.

Acacia Choriophylla - (Tamarindillo) In addition to possessing extreme drought-tolerance, cinnecord is a great contributor toward the development of a naturalized thicket. Sprawling, shrubby, multi-trunk tree with shiny leaves and fragrant yellow flowers. Natural height is under 20 feet. Because it forms multiple trunks, it takes trimming well and can be trained to fill in whatever height you desire. Does not have deadly thorns like other acacias.

Several cladistic analyses have shown that the genus Acacia is not monophyletic. While the subg. Acacia and subg. Phyllodineae are monophyletic, subg. Aculeiferum is not. This subgenus consists of three clades. Therefore, the following list of Acacia species cannot be maintained as a single entity, as this genus is being divided into 5 genera, Acacia, Vachellia, Senegalia, Acaciella and Mariosousa. The new type species of Acacia has become Acacia penninervis.

Which of these segregate genera is to retain the name Acacia has been somewhat controversial. The genus was previously typified with the African species Acacia scorpioides (L.) W.F.Wright, a synonym of Acacia nilotica (L.) Delile. Under the original typification, the name Acacia would stay with the group of species currently recognized as the genus Vachellia. Orchard and Maslin proposed a retypification of the genus Acacia with the species Acacia penninervis Sieber ex DC., an Australian species that is a member of the largest clade within Acacia, a primarily Australian group formerly recognized as Acacia subgenus Phyllodinae, on the basis that this results in the fewest nomenclatural changes. Although this proposal met with strong disagreement by some authors, it was accepted on 16 July 2005 by the XVII International Botanical Congress in Vienna , Austria. Consequently, the name Acacia is conserved for 948 Australian species, 7 in the Pacific Islands, 1 or 2 in Madagascar and 10 in tropical Asia. Those outside Australia are split between the genera Acaciella, Mariosousa, Senegalia, and Vachellia.

Thanks again to Wikipedia for the online encyclopedia information.

Click here for more photos of Oaxaca, Mexico for this day.