Chrysophyllum imperiale again, and again

I've mentioned what I call the Royal Tree, Chrysophyllum imperiale, a few times now in my blog. I proclaimed it to be my favourite plant in Sydney, resulting it appearing in this painting (along with ginger and some wollemi pines in the background) by Hadyn Wilson (at right).

The specimen in Sydney's Royal Botanic Garden certainly has a fine royal pedigree. As I explained in a 2009 post, Queen Victoria's son Prince Alfred planted this tree during an eventful visit to Australia in 1868 (he survived an assassination attempt while in Sydney).

The species name imperiale I gather is more a reference to its impressive leaves and perhaps (like the genus name) also to its golden (to rusty tawny) tinged new growth, than any connection with royalty. The 150-year-old specimen in Sydney displays these attributes well.

Chrysophyllum is classified in the plant family Sapotaceae, along with various genera hardly known in Australia but important in tropical regions for timber, food and medicine. Chrysophyllum canito yields the star apple, but otherwise this genus is mostly for ornament and local habitat.

Earlier this year I saw another fine specimen of Chrysophyllum imperiale, this time in the botanic garden of Buenos Aires (Jardín Botánico Carlos Thays) where as I reported two weeks ago they also do a nice line in mariposas. Their tree didn't always look so good, and to be fair it's on the mend rather than in peak condition. Until a few years ago a sewer from the administration building overflowed or somehow released its contents into the soil nearby. Once that flow was stemmed, the tree started to improve almost immediately, albeit retaining a yellowish complexion.

The Director, Graciela Barriero, was unable to tell me how old the tree was but I imagine it was planted early in the twentieth century by the original designer of the garden, Carlos Thays.

The species itself is extremely rare and probably extinct in its natural habitat around Rio de Janeiro in Brazil. In fact while I was in Sydney we were approached by either the botanic garden or environmental agency for seed to use for restoration.

I forgot on my visit to Jardim Botanico do Rio de Janeiro to look out for this species but emailed the Director of Environment and Technology, Claudison Rodrigues, soon after I returned to ask whether they had any specimens in the botanic garden. The response was yes, four plants, all 'young, but strong' plus a few waiting to be planted out. I wonder if these are from seed we provided from Sydney?

In any case, it's a tree that could be grown more widely in botanic gardens. A bit big for most home gardens but a fascinating and attractive specimen tree for a specialist collection.

I hadn't noticed any here in Melbourne's Royal Botanic Gardens but was pleased to discover some on our census. There are just a couple, tucked away to give them protection from the hot Melbourne summer, and perhaps its cool winters, but in time I expect they too will emerge through the undergrowth to attract right royal attention.

Postscript (14 July 2015, 8.00 am): This morning I found this note, posted on the Tropical Fruit Forum on 11 October 2012, by Paul Recher from Dorroughby in far north-eastern NSW, Australia: 
This tree [i.e. Chrysophyllum imperiale] is native to the Atlantic, from the coastal region of Rio de Janeiro (today almost entirely urbanized area) to the southeast of the state of Minas Gerais, in the Parque do Rio Doce. [It] was abundant at the time of colonial Brazil, today is considered endangered in the wild. Being a large tree, very hard wood, and beautiful and tasty fruit, was appreciated by Emperor D. Pedro I, and also by his son, D. Pedro II, who sent copies to botanical gardens around the world. During the Second Empire and was unusual because of its logging for timber to build their ships, becoming even rarer after the end of the Empire. Incredibly, Republicans Pernambucana the famous Revolution of 1817 cut all copies, including growing in Brazilian gardens by the fact that his name was associated with the Emperor! Until the early twenty-first century, there were only a few known specimens, all adults, and most outside Brazil, in the following collections:

• Botanical Garden of Lisbon, Portugal (planted in 1878) 
• Farroupilha Park in Porto Alegre, Rio Grande do Sul 
• Royal Botanic Gardens in Sydney, Australia (planted in 1868) 
• Carlos Thays Botanical Garden, in the city of Buenos Aires, Argentina 
• Botanical Garden of Brussels, Belgium 
• Botanical Garden of Florence, Italy 

There is now a group of people from several countries that deals with the search and preservation of specimens of this species and work to reproduce by seeds. This is a work of great importance as it will allow the restoration and maintenance of the same individuals in the wild, so to save the endangered species. This group achieved two major successes: relict specimens discovered in the wild, in the region of the Parque Estadual do Rio Doce and Pingo Dagua east of Minas Gerais. were also discovered at least one copy in a remnant of native forest in the state of Rio de Janeiro in submontane forest environment ombrófila dense, at an altitude of 200 m around the Baía Guanabara. It measures about 20 to 25 m high, and appears to have more than 100 years old. Currently, in parts of Minas Gerais, Rio de Janeiro and São Paulo are planted several individuals of this species, which grow with some difficulty, because it is a slow growing tree and very demanding on soil and climate. The copy of the photograph [the same tree in Buenos Aires that I photographed] is the oldest of those found in Argentina, and was sent by D. Pedro II. J. In this Botanical grow two more copies of more than 10 years, generated from seeds that were sent from Sydney. From the same origin and age is the individual who grows in the Botanical Garden of the Faculty of Agriculture of Buenos Aires.