Cold hardy Eucalyptus hybrids... in the Danish Fjords!

Identifying Mystery Eucalyptus: The case of E. gunnii x nitens hybrids... in Denmark!

Gustavo Iglesias Trabado
GIT Forestry Consulting - Consultoría y Servicios de Ingeniería Agroforestal - www.git-forestry.com - EUCALYPTOLOGICS

We have previously showed you around here different cases of "odd eucalypts" growing in different parts of the world. First, the case of our friend Ian Barclay at the Desert Northwest finding a new eucalypt hybrid (Eucalyptus crenulata x nitens) growing among his ornamental plant stock. Then, some stories about hybrid E. gundal (Eucalyptus gunnii x dalrympleana) developed in France for forestry purposes. And some more blabla about Eucalyptus globulus x nitens, another potentially interesting hybrid choice for timber production.

Today we bring you some more about eucalypt hybrids. In this case, a type with some interest for those growing the ubiquitous Australian trees in the boundaries of their tolerance to cold. From Denmark, after enduring 8 winters, and thanks to Martin Reimers, we take a peek at Eucalyptus gunnii x nitens ... in two botanical plates!

Fig. 1: Botanical assessment of photographic samples leading to the identification of Martin Reimers' mystery Eucalyptus growing in the Northern shores of the Flensburg Fjord, Denmark, as a hybrid Eucalyptus gunnii x nitens. (Click the image to enlarge, 1280 x 1024 pix)

Product of the viable cross of two relatively closely related eucalypt taxa (both E. gunnii and E. nitens belong to subgenus Symphyomyrtus, Section Maidenaria, and differ just as part of Series Orbiculares and Series Globulares respectively, so they are somewhat "close cousins") , this particular interserial hybrid combination would be very unlikely without human intervention, since each species has its habitat at one side of the Bass Strait.

Fig. 2: Complementary botanical assessment of E. gunnii x nitens depicting the juvenile organs of both parent species and the hybrid cross. (Click image to enlarge, 1024 x 768 px).

Interestingly, Martin's tree shows some of the well desired effects of heterosis, and of a lucky combination of inherited good form, fast growth and cold hardiness. Precisely, if at some point we hinted that E. globulus x nitens could be of interest for some addition of cold hardiness to a benchmark species for short rotation timber plantations, this time the addition comes "on the other side of the frost spectrum".

Not in vain, fast growing E. nitens, a relatively cold hardy eucalypt species for temperate atlantic climates, able to tolerate a good number of frost events each winter but not extremely well adapted to harsh winters much beyond USDA Hardiness Zone 8a has, in this case, crossed with one of the cold hardiest eucalypts, the Tasmanian Cider Gum, able to survive in USDA Zone 7a. A promising sign for its, by now, good performance in an area of the world you would not instantly associate to the Australian trees.

Some Interesting Literature...

Listed below, some relevant bibliographic sources for cases like this, which could give the reader some insight on the mechanisms that made hybrid Eucalyptus trees like Martin's possible, and beyond possible, understandable. Reasons enough for compliments to be always sent to the Eucalyptus of France and Tasmania.

Cauvin B, Potts BM & Potts WC (1987). Eucalyptus: Hybridation artificielle - barrieres et hérédité des caracteres. Annales de Recherches Silvicoles 1986, AFOCEL, Paris. pp. 255-303.

Tibbits WN, & Reid JB (1987). Frost resistance in Eucalyptus nitens (Deane & Maiden) Maiden: genetic and seasonal aspects of variation. Australian Forest Research, 17 (1), 29-47 DOI: 0004-914X

Tibbits WN & Reid JB (1987). Frost Resistance in Eucalyptus nitens (Deane & Maiden) Maiden: Physiological Aspects of Hardiness. Australian Journal of Botany, 35 (3), 235-250. DOI: 10.1071/BT9870235

Griffin AR, Burgess IP & Wolf L (1988). Patterns of Natural and Manipulated Hybridisation in the Genus Eucalyptus L'Hérit. A Review. Australian Journal of Botany, 36 (1). DOI: 10.1071/BT9880041

Tibbits WN (1988). Germination and Morphology of Progeny From Controlled Pollinations of Eucalyptus nitens (Deane & Maiden) Maiden. Australian Journal of Botany, 36 (6). DOI: 10.1071/BT9880677

Tibbits WN (1989). Controlled Pollination Studies with Shining Gum (Eucalyptus nitens (Deane & Maiden) Maiden). Forestry, 62 (2), 111-126. DOI: 10.1093/forestry/62.2.111

Tibbits WN, Potts BM & Savva, MH (1991). Inheritance of freezing resistance in interspecific F1 hybrids of Eucalyptus. Theoretical and Applied Genetics, 83 (1). DOI: 10.1007/BF00229235

Bookmark this Interesting Link...

Besides growing several cold hardy Eucalyptus species with good potential for survival in the Eastern coast of Jutland, our fellow forester Martin Reimers has started to put together a wonderful database of performance for recently cultivated Eucalyptus all over Denmark.

www.eucalyptus.dk = Eukalyptus i Danmark = The database of Eucalyptus Cultivation in Denmark

Besides a growing amount of information on the history of Eucalyptus cultivation in Denmark, at www.eukalyptus.dk you can find fine photographic examples of E. gunnii (Cider Gum), E. gunnii x nitens, E. perriniana (Spinning Gum), E. dalrympleana (Mountain White Gum), E. pauciflora ssp. debeuzevillei (Jounama Snow Gum), E. pauciflora (White Sallee), E. nitens (Shining Gum), E. urnigera (Urn Fruited Gum) E. rubida (Candlebark), E. barberi (Barber's Gum), E. coccifera (Tasmanian Snow Gum), E. johnstonii (Tasmanian Yellow Gum), E. subcrenulata (Alpine Yellow Gum) and E. delegatensis (Alpine Ash) including detailed records of their cultivation and behaviour in such an apparently impossible location as the fjords, plains and islands of Denmark.

Some of these grow in the grounds of tree famous places as Copenhagen's Botanical Garden , recent receiver of Eucalyptus wedding gifts of Australia to Crown Princes Frederik and Mary; or as Hørsholm Arboretum, the largest collection of trees and shrubs in Denmark. But many do thrive also in the gardens of adventurous horticulturalists and private plant collectors scattered over the country, proving that at least the cold hardiest species within the genus can survive and bloom in yet another piece of Scandinavia.

Also in EUCALYPTOLOGICS... THE EUCALYPTUS OF THE FJORDS

Northernmost flowering Eucalyptus: E. dalrympleana at 61ºN in the Norwegian Fjords

Visit Frank Diron's Little Australia growing at Fanø Island in Denmark!

Want to contact us?

Contact GIT Forestry Consulting - Eucalyptologics

GIT's Eucalyptology Topics

Subscribe to receive EUCALYPTOLOGICS via RSS

Subscribe to receive EUCALYPTOLOGICS via e-mail

© 2007-2009 Gustavo Iglesias Trabado. Please contact us if you want to use all or part of this text and photography elsewhere. We like to share, but we do not like rudeness.

Click to Read Full Story...

Click to Display Summary only...

New Eucalyptus taxon described in Tasmania

Nicolle, D and Potts, BM and McKinnon, GE (2008) Eucalyptus cordata subsp. quadrangulosa (Myrtaceae), a new taxon of restricted distribution from southern Tasmania. Papers and Proceedings of the Royal Society of Tasmania, 142 (2). pp. 71-78. ISSN 0080-4703 [Download, PDF file, 4.2 MB]

Thanks to...

Subscribe to Eucalyptologics

GIT's Eucalyptology Topics

Subscribe to receive EUCALYPTOLOGICS via RSS

Subscribe to receive EUCALYPTOLOGICS via e-mail

© 2007-2008 Gustavo Iglesias Trabado. Please contact us if you want to use all or part of this text and photography elsewhere. We like to share, but we do not like rudeness.

Click to Read Full Story...

Click to Display Summary only...

Eucalyptus species identification (V): leaves help

By their fruits ye shall know them (V)

Even more tips on Eucalyptus Identification

Gustavo Iglesias Trabado
GIT Forestry Consulting - Consultoría y Servicios de Ingeniería Agroforestal - www.git-forestry.com

EUCALYPTOLOGICS

We have previously seen in EUCALYPTOLOGICS how bark features alone can be misleading for accurate Eucalyptus species identification, showing examples of different bark types for the same eucalypt species and of similar bark types for different eucalypt species. We have also seen how in some cases just a small sample of flower buds can work well, and also an example of how even just a distant photograph of Eucalyptus seed cups (fruits) can yield an accurate identification. Today we will see yet another different case, in which inflorescence similarities force the consideration of other details.

Fig. 1: Example of leaf comparison assisting flower comparison for accurate Eucalyptus species identification (Click image to enlarge)

Our friend Barrie at Las Palmas Norte-Hardy Palm & Exotics (Lantzville, British Columbia) reported the case of a mystery Eucalyptus in Canada that might require a confirmation of its identification.

The main doubt arising was its striking similarity to a Snow Gum (E. pauciflora and allied species and subspecies) for a good number of visual parameters.

Indeed, pictures of the tree in question showed similarities for flower bud clusters, general leaf shape, and not a too dissimilar bark outlook for the case of a young specimen. The most likely candidate within the Snow Gums to match this tree was E. pauciflora ssp. pauciflora, a normally narrow leaved form of the species.

The alternative species suggested by our also eucalyptologist friend Ian Barclay at The Desert Northwest (Sequim, Washington) was E. kybeanensis, the Kybean Mallee Ash.  And he might well be totally right.

The plate above provides a comparative view of both species, depicting their similarities for flower buds and bloooms, but also showing how, for this case, observation of leaf shape and size, but more importantly, of leaf venation patterns, can yield an accurate Eucalyptus identification.

In other words: "by their buds and fruits you will know them, but do not forget the other details".

Also in Eucalyptologics...

Example of "fruit based" diagnosis useful for accurate Eucalyptus species identification (Click image to enlarge)

Example of "flower bud only" diagnosis useful for accurate Eucalyptus species identification

Example of "bark only" diagnosis misleading Eucalyptus species identification (Click image to enlarge)

Example of botanical sample gathering methodology for accurate Eucalyptus species identification (Click to enlarge)

Different simultaneous stages of the reproductive cycle and eucalypt seed maturation process in a standing Snow Gum Eucalyptus tree.(Click to enlarge)

After Eucalyptus seed collection: examples of Eucalyptus seedling nursery stock for afforestation (Click to enlarge)

Find a local expert to ID your Eucalyptus

If you have an unknown eucalypt around and you are able to collect and photograph samples of the key organs needed for identification, do not hesitate contacting GIT Forestry Consulting.

If you are in the USA and find it easier to post fresh samples to a local expert, you can also contact Dr. Matt Ritter, resident eucalypt hunter at the California Polytechnic State University.

Visit Cal Poly Plant Conservatory

Contact us / Subscribe to Eucalyptologics

Contact GIT Forestry Consulting - Eucalyptologics

GIT's Eucalyptology Topics

Subscribe to receive EUCALYPTOLOGICS via RSS

Subscribe to receive EUCALYPTOLOGICS via e-mail

© 2008 Gustavo Iglesias Trabado. Please contact us if you want to use all or part of this text and photography elsewhere. We like to share, but we do not like rudeness.

Click to Read Full Story...

Click to Display Summary only...

Eucalyptus species identification (IV): fruits work

By their fruits ye shall know them (IV)

Yet more tips on Eucalyptus Identification

Gustavo Iglesias Trabado
GIT Forestry Consulting - Consultoría y Servicios de Ingeniería Agroforestal - www.git-forestry.com

EUCALYPTOLOGICS

We have previously seen in EUCALYPTOLOGICS how bark features alone can be misleading for accurate Eucalyptus species identification, showing examples of different bark types for the same eucalypt species and of similar bark types for different eucalypt species. We have also seen how in some cases just a small sample of flower buds can yield an accurate identification. Today we will see how just a distant photograph of seed cups (fruits) can yield a very promising species identification.

Fig. 1: Example of fruit based diagnosis useful for accurate Eucalyptus species identification (Click image to enlarge)

Our good friend Phil at Eucs-In-Habitat reported a mystery Eucalyptus growing in San Fernando Valley. Drew, the local observer in California, followed our recommended sequential observation process for eucalypt identification and took photographs of the overall outlook of the tree, its bark and of reproductive organs (blooming flowers, but more importantly, seed cups, the fruits).

Fig 3: Blooming Eucalyptus cladocalyx in California. Image courtesy of Drew_2008. (Click image to enlarge)

These fruit samples, even if just photographed using a zoom, are what allows a very good bet as botanical identification of this Eucalyptus tree (see Fig. 1) by comparison to a botanical plate prepared with locally collected samples. And the solution was Eucalyptus cladocalyx, also known by its vernacular name Sugar Gum.

In addition, once again a look back in time paying attention to previous eucalypt experts can yield complementary data to support or reject an attempt of Eucalyptus species identification.


"When Eucalyptus plantation testing was at its height in California, sugar gum was fourth in popularity, amounting to about one tree in 25. So although old specimens are not common today, nevertheless there are always some not far away. (...) The tall smooth boles are free from lower branches and are in many cases recognizable on sight by warm-colored bark, with long vertical fissures and horizontal rows of dimples left over from insect bites years ago. On the ground you can pick up distinctive barrel-shaped fruit in clusters of up to 15 in number; these clusters in themselves suffice to give you confidence that you are under a sugar gum the next time you see them among the ground litter."

Ronald N. Bracewell (2005) Trees of Stanford and its Environs.

Eucalyptus species identification for this tree as E. cladocalyx makes sense then both in botanical but also in geographic and historical contexts. No doubt, once again we can see Eucalyptology is an interdisciplinary science.

Acknowledgements

To Matt Ritter for his efforts botanising Californian Eucalyptus and discovering Australian giants in the Sunny State. To John Rawlings and the team at Stanford Grounds Service for their effort not only preserving but also publicising online the botanical heritage of the campus. And to Ron Bracewell, possibly at this moment planting Eucalyptus and radio telescope antennas somewhere beyond our knowledge.

Also in Eucalyptologics...

Example of "flower bud only" diagnosis useful for accurate Eucalyptus species identification



Example of "bark only" diagnosis misleading Eucalyptus species identification (Click image to enlarge)

Examples of distinct flower bud characteristics in different Eucalyptus species. (Click image to enlarge)

Example of botanical sample gathering methodology for accurate Eucalyptus species identification (Click to enlarge)


Different simultaneous stages of the reproductive cycle and eucalypt seed maturation process in a standing Snow Gum Eucalyptus tree.(Click to enlarge)


After Eucalyptus seed collection: examples of Eucalyptus seedling nursery stock for afforestation (Click to enlarge)



Find a local expert to ID your Eucalyptus

If you have an unknown eucalypt around and you are able to collect and photograph samples of the key organs needed for identification, do not hesitate contacting GIT Forestry Consulting.

If you are in the USA and find it easier to post fresh samples to a local expert, you can also contact Dr. Matt Ritter, resident eucalypt hunter at the California Polytechnic State University.

Visit Cal Poly Plant Conservatory

Contact us / Subscribe to Eucalyptologics

Contact GIT Forestry Consulting - Eucalyptologics

GIT's Eucalyptology Topics

Subscribe to receive EUCALYPTOLOGICS via RSS

Subscribe to receive EUCALYPTOLOGICS via e-mail

© 2008 Gustavo Iglesias Trabado. Please contact us if you want to use all or part of this text and photography elsewhere. We like to share, but we do not like rudeness.

Click to Read Full Story...

Click to Display Summary only...

Eucalyptus species identification (III): buds work

By their fruits ye shall know them (III)

More small tips on Eucalyptus Identification

Gustavo Iglesias Trabado
GIT Forestry Consulting - Consultoría y Servicios de Ingeniería Agroforestal - www.git-forestry.com

EUCALYPTOLOGICS

We have previously seen in EUCALYPTOLOGICS how bark features alone can be misleading for accurate Eucalyptus species identification, showing examples of different bark types for the same eucalypt species and of similar bark types for different eucalypt species. Today we will see how in some cases just a small sample of flower buds can yield an accurate identification.

Fig. 1: Example of flower bud based diagnosis useful for accurate Eucalyptus species identification (Click image to enlarge)

Our good friend Dan at Tree-Species.com found a strange looking Eucalyptus growing in Málaga and followed our recommended sequential observation process for eucalypt identification. He later sent us photographs of the overall outlook of the tree, its bark and of samples of reproductive organs (flower buds & seed cups) he collected from the tree.

Fig. 2: Examples of distinct flower bud characteristics in different Eucalyptus species. (Click image to enlarge)

These flower bud samples were what allowed an accurate botanical identification of this Eucalyptus tree (see Fig. 1) by comparison to an holotype (botanical plate) and to specimens of that eucalypt species growing in its natural Australian habitat. And the solution was Eucalyptus gomphocephala, literally meaning "bolt-headed well-covered flower", also known by its vernacular name Tuart.

In addition, a look back in time and paying attention to eucalypt experts of the past does normally yield some sort of useful complementary data that helps to support or reject a purported Eucalyptus species identification. O Grande Ernesto diz:


"In the Mediterranean Basin it follows E. camaldulensis and E. globulus as the most used species for afforestation, especially in Northern Africa. It has been promoted in Southern Morocco to plant on calcareous soils, mostly on coastal dunes. Actually, existing plantations on the dunes of Agadir and Mogador and at Sidi Bibi have proven this species to be of great interest, both as a way to fight the moving sands and as allowing to achieve a valuable production in these vast and previously improductive areas. (...) Total acreage planted with E. gomphocephala in Morocco reaches some thousand hectares. Also in Algeria, Tripolitania, Cyprus and Israel it is a quite planted species. In other Mediterranean countries only in Spain it has been used for plantings of certain importance, especially in the coastal dunes of Malaga."

Ernesto da Silva Goes (1960) Os eucaliptos em Portugal.

Eucalyptus species identification for this tree as E. gomphocephala makes sense then both in a botanical and an historical sense. No doubt, Eucalyptology is an interdisciplinary science.

Fig 3: Fruits of Eucalyptus gomphocephala. Image courtesy of Tree Species.

Acknowledgements

To the Royal Botanic Gardens Sydney & Botanic Garden Trust for their kindness allowing educational use of their Australian plant images. To Martin Pritchard & The Busselton-Dunsborough Environment Centre for their effort in preservation and divulgation of the uniqueness of Ludlow Tuart Forests, where the tallest E. gomphocephala in the world still survive. To Dan Anderson & Tree Species for choosing EUCALYPTOLOGICS as their Eucalyptus advisors.

Also in Eucalyptologics...



Example of "bark only" diagnosis misleading Eucalyptus species identification (Click image to enlarge)

Example of botanical sample gathering methodology for accurate Eucalyptus species identification (Click to enlarge)

Anthesis in Eucalyptus robusta (Swamp Mahogany) flowers.
Photography by Brian Johnston (Click image to enlarge)

Maturation stages for eucalypt fruits collected on Corymbia calophylla (Marri) trees in a single visit, showing some of the internal organs within Eucalyptus infrutescences in each phase. (Click to enlarge)

Different simultaneous stages of the reproductive cycle and eucalypt seed maturation process in a standing Snow Gum Eucalyptus tree.(Click to enlarge)

After Eucalyptus seed collection: examples of Eucalyptus seedling nursery stock for afforestation (Click to enlarge)



Find a local expert to ID your Eucalyptus

If you have an unknown eucalypt around and you are able to collect and photograph samples of the key organs needed for identification, do not hesitate contacting GIT Forestry Consulting.

If you are in the USA and find it easier to post fresh samples to a local expert, you can also contact Dr. Matt Ritter, resident eucalypt hunter at the California Polytechnic State University.

Visit Cal Poly Plant Conservatory

Contact us / Subscribe to Eucalyptologics

Contact GIT Forestry Consulting - Eucalyptologics

GIT's Eucalyptology Topics

Subscribe to receive EUCALYPTOLOGICS via RSS

Subscribe to receive EUCALYPTOLOGICS via e-mail

© 2008 Gustavo Iglesias Trabado. Please contact us if you want to use all or part of this text and photography elsewhere. We like to share, but we do not like rudeness.

Click to Read Full Story...

Click to Display Summary only...