Tuesday, 19 June 2018

Velvet cactus mostly displaced by Mexico City


'Feel the surface of this cactus' said Manuel (Bonilla Rodríguez), pointing at a large Opuntia in front of me. Now I've grown Opuntia in the past and I know that they have tiny little irritating 'glochids' among their spines, and you want to avoid getting them stuck in your skin (a magnifying glass and tweezers are needed to remove them all).

It turned out he meant the surface of the cactus stem (or cladode), in between the glochids and spines. It was worth it. So soft and velvety. Quite unexpected in big tough cactus.


It is the aptly named Opuntia tomentosa, its surface covered in soft, short hairs. This is not an uncommon cactus and was one of the first to be brought into cultivation in Europe from its native habitat in Mexico and Guatemala.

Indeed, according to A History of Succulent Plants (by Gordon Douglas Rowley), the Bavarian Prince-Bishop of Eichstatt was in the (late) 16th century able to brag about his giant Opuntia tomentosa: 'an estimated 3,000 joints and 5.5 metres tall with a circumference of 19 metres'. The cactus was one of only a small number of succulent plants from South Africa and Central America to feature in Hortus Eystettensis (by Basil Besler), a book published in 1613 documenting all the plants grown at Eichstatt Castle.


[This illustration is from www.plantillustrations.org where is is labelled as Opuntia ficus-indica, and indeed the label hints at that name, but Mr Rowley seems convinced it is Optuntia tomentosa.]

In Australia it is also not uncommon. The Velvet Tree Pear is a declared weed in New South Wales, Northern Territory, Queensland, South Australia and Western Australia. Generally you shouldn't grow or spread it in this country.

If you were to do so (but you can't), or you track some down as an environmental weed, you'd notice the beautiful velvet surface and the colourful flowers - mostly yellow with red outer markings. For the botanical aficionado, as with other cacti, many of the brightly coloured floral adornments are petal-like sepals (the outer, usually green appendages) rather than true petals. We call these petaloids.


In Mexico City the Velvet Tree Pear is part of the original vegetation that lined the large lake now (after draining) replaced by that city. In a restored remnant near the National Autonomous University of Mexico you can find plenty of this species nestling alongside Agave salmiana, Echeveria gibbiflora and the occasional dryland oak, Quercus deserticola.


Tuesday, 12 June 2018

Rhythmic rumble of hompak the sound of cultural coevolution


While on the subject of agave (see last week's post), there is one quite eccentric use I didn't mention, as a musical instrument. Not the whole plant - that wouldn't make any sense - but the hollowed out flowering stem.

The hompak is a long wooden instrument with a flared distal end. Something like an unfurled trumpet or perhaps a shortened alphorn. I can't find much background but it seems to have originated in the Mexican region during Mayan times (this next image is part of a mural I saw at the Museo Nacional de Anthropologia).


As you can see at the top of the post, my Mexican friend Manual Bonilla Rodríguez not only has one, but plays it. The extraordinary part is that he plays it, and it sounds, like an Australian didgeridoo. Cultural co-evolution says Manual.

I can attest to it sounding very similar to the didgeridoo played by the Australian Indigenous people of northern Australia. It even requires circular breathing, which although used with various more commonly encountered wind instruments is essential for creating the distinctive pulsating drone of the didgeridoo.

Here is Clarence Slockee playing the didgeridoo at the Blue Mountains Botanic Garden at Mount Tomah, New South Wales, in 2005, followed by Manual at the National Autonomous University of Mexico in 2018.


Of course you can play any long, hollowed out, tube in the style of a didgeridoo. A university friend of mine used to show off by playing a vacuum cleaner, although the sound wasn't quiet as mellifluous as that produced by wood.

There are differences between the hompak and didgeridoo. The flared end for starters. Also the source of the tube.


Above you see a didgeridoo carried in the Woggan-ma-gule ceremony held at Royal Botanic Garden Sydney on 26 January 2007. Mostly it's made from a hollowed out eucalypt branch, traditionally with the hard work done by termites.


In Mexico, it's the hollowed out flowering stem of an agave, with the trumpet end due to the flaring of the stem at its base. A small segment - maybe 15 centimetres long - of bamboo is added at the mouth end, but no wax is applied (unlike the Australian didgeridoo).

To finish, I saw another cultural pursuit in Mexico City that to my knowledge Aboriginal Australians have - quite sensibly - not taken up, Voladores de Antropologia (literally, Flyers of Anthropology). I won't go into all the details but essentially four people dangle upside down from ropes that unravel and rotate from the top of a rather long pole until the 'flyers' reach the earth. It began, I understand, in the rainforest trees of southern Mexico. Today you can, if you are lucky, see it in this park setting in Chapultepec.



Tuesday, 5 June 2018

On pulque, you regret the 400-rabbit nights


'Pulque is the product of a sexually frustrated agave'. That's what I said a few years ago, in a post praising the latest book by Amy Stewart called The Drunken Botanist.

It's more or less true. Pulque is a drink having a bit of revival in Mexico according to my friend Manual Bonilla Rodríguez. He likes it, although his father is more inclined to Tequila. The Spanish reported in the 1780s that about 16.5 million gallons of pulque were produced each year in Mexico. I get the sense that dropped in the early 20th century but may now be on the way up.


Both drinks are produced from the agave plant, that large blue-grey succulent you see straying occasionally into roadside verges and most noticeable when, after some 25 years, it sends up a towering flowering stalk to produce bright yellow flowers. The parent plant then dies, to be replaced by pups at its base. (And yes, that's a humming bird I captured in this close-up of agave flowers.)


To create pulque, the flower stalk is cut off before it has a chance to bloom. The base of the plant is lanced and begins to rot. Bacteria and other microorganisms move in, fermenting the sap which continues to flow as the squishy insides are scraped away.

This farming of pulque continues for many months and a single plant can produce 1000 litres or more. I said last time that that 'pulque is apparently not very nice to drink' (and has a rather stringent odour) but Manual assures me that's not the case. However he wondered if it might contain a few too many unfamiliar bugs* to make it comfortable drinking for visitors such as myself (as it happens there was no opportunity to try it).

In my recent visit I didn't advance my understanding of pulque much further but it was pointed out that Agave salmiana, a local species to Mexico City, was one that is commonly milked to produce the moderately (4-6%) alcoholic beverage. This is a specimen growing wild near the National Autonomous University of Mexico, and the specimen towards the top of this post is from the nearby botanic garden.


Pulque has a long history in the region and one of the permanent displays at the Museo Nacional de Anthropologia concerns Pulque Culture, featuring of all things, rabbits! In Aztec and other central Mexican cultures, the goddess (or female divinity) Mayahuel was strongly associated with the agave. You can see this from the symbolic image of Mayahuel at the top of my post (taken from the exhibition display), with the upper torso emerging from spiny leaves.

The agave gave the people plenty of products, such as roofing materials, fibre for ropes and weaving, tasty worms and of course pulque. It seem that the patron of pulque was the god Ome Tochtli, the 'Two Rabbit'. Drinking more than a single serve was prohibited due the fear that anyone drunk on pulque would 'fall under the influence of the Cenzon Totochtin, the 'Four Hundred Rabbits'. This would lead to loss of control, and aggressive and violent behaviour. So two rabbits good, 400 rabbits not so good.


On the way to the airport to fly out of Mexico City we passed a brightly coloured Pulqueria, a place were you might go to try the product. Unfortunately we were unable to stop for a photograph, let alone a tasting, so I give you this photograph taken on Plaza Garibaldi, Mexico City, in October 2007 (from Wikipedia Commons).


*Postscript: Paul Ward, on Facebook (5 June 2018) notes that Pulque is 'an interesting mixed culture ferment' with 'one of the main microbes ... a bacterium rather than a yeast, Zymomonas mobilis'. Paul adds that this bacterium can tolerate high alcohol concentrations, up to 15-16%, and that Pulque producers are very protective of their starter cultures.

Tuesday, 29 May 2018

The man in the arum, and other floral inventions in Mexican culture


A flower for every day of the year, from the Mayans to modern Mexico. That's La flor en la Cultura Mexicana, the latest exhibition at Mexico City's Museo Nacional de Antropología.

The story of floral representation over at 2000 years is told through 365 pieces. At the opening in March, the Director of the Instituto Nacional de Antropología e Historia, Diego Prieto Hernández, explained that this exhibition demonstrated that our heritage can be appreciated through aesthetic, sensual and emotional responses as well as through academic research.

There are five themes, starting with the flower as a metaphor for things of value (from pre-Spanish times).


Then its the discovery of the new world, partly through its flora, including the 16th century herbal Códice de la Cruz-Badiano, often just called the Codex, as well as 36 spectacular (yes) herbarium specimens from the National Autonomous University of Mexico (UNAM).


The third theme is the flower as an allegory for the divine, including religiously inspired oil paintings by various renowned Spanish artists and a couple of sculptural pieces.


The flower as a symbol of beauty comes next, with strong associations in eroticism and the female form. Diego Rivera's work is included here. Finally, contemporary art such as the use of flowers in displays for the Day of the Dead and fashion.


Amid all this florifery I was struck at the very start of the exhibition by Flor de granada, an 18th century silver sculpture featuring a favourite symbol of mine, the pomegranate. In this case it is said to represent the immaculate conception of Jesus. Each to his own I guess.

As with any artwork, it's story continues. Six of its petals were stolen during the Mexican Revolution, leaving only two to enjoy today.


I'm afraid you'll have to rush to Mexico City if you want to see it. The exhibition closes on my birthday, 17 June.


Tuesday, 22 May 2018

Papery bark wraps something like a biblical king's gift


I was about to say that if you don't live in the tropics you ain't gunna see Bursera. I couldn't recall seeing any growing around Melbourne and I don't remember it from outdoors in London. To be sure though I checked our 'living collections census' here at the Royal Botanic Gardens Victoria.

Turns out we have one listed - Bursera hindsiana from Mexico - but none seem to be surviving today. One was planted in the Arid Garden, which makes sense, and another in our Grey Garden, which is consistent with the tone of the foliage. However it's the bark I'm interested in. The red, papery bark found on so many of the Bursera species. Many but not so much this particular species.

I don't have names for all the species I photographed in Mexico and Cuba but the peeling red bark made it hard to resist taking photos (and now sharing with you). To be fair, the general absence of leaves and flowers did focus the mind a little.

The first one I saw does have a name, Bursera arida. I was in Jardín Botánico Helia Bravo Hollis, in central Mexico. On one side of me was this columnar cactus.


On the other, a rather squat and leafless Bursera arida. On close inspection you could see the distinctively papery bark.


Back in Mexico City, at the botanic garden of the National Autonomous University of Mexico, we have this (unlabelled) Burseria. Perhaps the same species.



Far away in Cuba, in the Jardín Botánico Nacional de Cuba, I walked past this next tree every morning. It's clearly a Bursera and clearly not my little stumpy Bursera arida. This particular botanic garden is unusual in labeling very few of its specimens, and this was no exception.

It may be the rather common Gumbo Limbo, Bursera simaruba, which occurs from Florida through to Venezuela, including the Caribbean. This species is also called the Tourist Tree, which works for me, and has been used as a 'living fence' (I did see a lot of living fence posts in Cuba but none looked Bursera-like to me - at least as rumbled by on the highway).


There are some 80 species of Bursera, most of them from Mexico, and all producing a fragrant resin called 'copal' (a name I mentioned last week in relation to the green-barked Parkinsonia). This resin is used for medicine, varnish and more commonly as an incense. The wider family, Burseraceae, is sometimes called the incense family, strengthened by the inclusion of genera that produce  frankincense (Boswellia) and myrrh (Commiphora).

You might find Bursaria microphylla, often called the Elephant Tree due to its slightly bloated and lumpy trunk, in the garden of a plant enthusiast in Tropical Australia*. Do let me know. I'm interested in whether any species could be described as commonly grown.

As an aside, though, not every papery barked shrub or tree in Mexico (or Cuba presumably) is a Bursera. Here is a Senecio growing in the restoration area near the University with similar looking trunk. This is a daisy, not a member of the incense family.


For Australians**, we have the beautiful West Australian Miniritchie, Acacia grasbyi, with its even more highly textured ribbons of red and brown. That one you can look up on the web.

Postscripts: *Dale Arvidsson, definitely a 'plant enthusiast' as well as Curator of Brisbane's botanic gardens, says 'Brisbane’s City Botanic Gardens has a great specimen of Bursera simaruba'
**And a few eucalypts I gather. I noticed Jane Edmundson admiring a ribbony barked gum at Melton Botanic Garden on this week's ABC TV Gardening Australia show. I'm sure there are others...

Tuesday, 15 May 2018

Greasy green trunk a bonus in the Mexican desert


Green trunks and stems are handy if you're a plant that drops its leaves during the sunniest months or, like a cactus, you have spines instead of leaves. That way you can - if you are a plant - us the abundant energy from the sun to produce food without those troublesome appendages that lose water so easily.

My example today is the elephantine skinned, Sonoran Palo Verde: the green(verde)-sticked(palo) plant from the Sonoran Desert. Now I haven't visited the Sonoran Desert in Arizona but I have seen this plant growing in central Mexico, near Tehuacán.


Parkinsonia praecox has gathered up quite a few scientific names over the years but it's enough to know it is in the legume family, grouped with Caesalpinia and similar plants. Its natural range extends from the southern Sonoran Desert through Mexico to dryer parts of Peru and Ecuador.

A local common name is Manteco, meaning fat or lard, perhaps a reference to the buttery texture of the bark. Another is Palo Brea, meaning green pitch or tar, probably also a reference to the bark layer, which is a bit like a strip of bitumen. Or both may be because the bark of this tree has been used to tan animal skins into leather.


The resin also has its uses, including an incense sold as Peruvian Gold Copal. You too can experience the 'wonderfully unique notes reminiscent of pumpkin or butternut squash'. Good enough to eat perhaps? And you can. Laboratory tests of mice indicate that at low levels the gum could be a safe food additive.

Palo Verde is the more general name, given to any of the 12 species of Parkinsonia, all with yellow flowers and green bark. In Northern Australia the sharply-spined Mexican Palo VerdeParkinsonia aculeata, is a problem weed of pastoral land.


The species photographed here was labelled Parkinsonia praecox in the nearby Jardín Botánico Helia Bravo Hollis, a species not, as far as I'm aware, (yet) a weed in this country.


The trees in the botanic garden infected with this beetle, generating a swollen golf-ball sized home on some of the branches. I have read about a dedicated beetle, called the Palo Verde Beetle (Derobrachus geminatus), but that seems to be an entirely different kind of creature whose larvae live in the soil.

The leaves were barely visible in early April but they are your typical feathery legume leaf. A few are emerging here near one late flower.


And while often (e.g.) described as having an umbrella shape, the trees I saw were relatively young and less expansive in the canopy.



Tuesday, 8 May 2018

Temperate House reopened, this time by Sir David not QEII


It's taken five years, £41 million, the repair of 69,000 individual parts (including the replacement of 15,000 panes of glass), 180 km of scaffolding and more than 5,000 litres of paint, but Kew Gardens' Temperate House is back in action.

Designed by Decimus Burton, the gentleman who gave us the Palm House at Kew Gardens, this giant glasshouse was first opened in 1863, although with additions it was not complete until 40 years later. Queen Elizabeth II reopened it in 1981 after its last major restoration. This time Sir David Attenborough, with Kew's Chairman, Marcus Agius, and Director, Richard Deverell, did the honours last week (on 3 May 2018).


At 4,880 square metres in area, the Temperate House is twice as big as the Palm House, and the largest still-standing Victorian glasshouse in the world. For more than 150 years it has been home to plants from Africa, Australia, New Zealand, the Americas, Asia and the Pacific Island. Plants that otherwise would shiver (and die) outside in the London climate.


In the freshly renovated glasshouse you can see 10,000 plants, representing 1,500 species, displayed to highlight conservation efforts to protect our temperate forests. The famous South African cycad Encephalartos woodii remains, a species extinct in its natural habitat. Today this cycad is found only in botanic gardens and private collections around the world, and Kew's specimen is one of the finest.

Closer to (my) home is a new addition, Johnson's Grass Tree (Xanthorrhoea johnsonii) from our show-winning garden designed by Jim Fogarty, 'Essence of Australia', at the RHS Hampton Court Palace Flower Show in 2014. We estimated at the time this specimen was possibly older than Hampton Court Palace itself, built in the 16th century. (This is Richard Barley, ex of Royal Botanic Gardens Victoria and now Director Horticulture, Learning and Operations at Royal Botanic Gardens Kew, with the specimen.)


There are more plants from that show garden, plus plenty of other species from Australia. They form part of a collection from just one of seven regions gathered together in this new display.

The interpretation is also very classy, with bit-sized science, maps and colour photos. The design is crisp and elegant as well. We can thank Sharon Willoughby, also ex of Royal Botanic Gardens Victoria for this! Here are the signs, with Richard and that cycad I mentioned above...


I was delighted to be at this reopening, a chance opportunity on my way to a botanic gardens meeting in Lisbon. The restoration project began when I was working at Royal Botanic Gardens Kew, as Director Conservation, Living Collections and Estates (with responsibility for the heritage buildings as well as horticulture at Kew Gardens and Wakehurst Place and the wonderful Millennium Seed Bank Partnership).

During my two-year sojourn, the planning was completed and most of the money raised - through the Heritage Lottery Fund; Kew's Government Department home, Defra; and some sizable private donations. Between my leaving in 2013 and today, all the cleaning, repair and painting happened. A big job and a beautiful result.

For the record, here it is in July 2014, soon after the glasshouse was cleared of plants. It's a year after I left working there and at the time of the Hampton Court Flower Show...