Tuesday, 3 March 2015

Begging for begonias

I shouldn't say beg, it was more like a coax and persuade maneouvre (but that doesn't alliterate as well). Back in December members of the Melbourne Begonia Society encouraged me, as they should, to grow more begonias in the Royal Botanic Gardens.

I was speaking to them about plans for the Melbourne and Cranbourne sites, with a glancing mention of begonias. Apart from their regular displays they prepared a selection of the species William Guilfoyle was growing in the Royal Botanic Gardens in 1883, and presented me with a list of the same.

I was also gifted a photo album including images of everything displayed, plus a few missing species to show me the beauty and breadth of Guilfoyle's collection. On that front, I didn't take much convincing. Begonia boliviensis (sometimes called 'Begonia boliviana' in horticulture*), the species I've used to illustrate this post, is just one of the colourful and sensuous plants on the list. 

And a decade ago, after a some initial hesitancy I became a big supporter of the begonia beds at Sydney's Royal Botanic Garden, approving the expansion by Peter Sharp and his volunteers (supported by Paul Nicholson and other staff) into a second bed (photographed here at its opening in 2007).

In my talk I mentioned the possibility of a new glasshouse at the Melbourne site, the prefect place for begonias in Melbourne. Some grow outside, like the Begonia boliviensis photographed near my front entrance at home, but many more would grow under glass.

I'm surprised I haven't posted anything about begonias yet. As compensation, let me give you some fast facts from my friend Peter Sharp's lovely book, Down to Earth with Begonias.

There are around 1500 species of Begonia, and undoubtedly more to be discovered and described, so I needn't try to grow them all. They are divided up into cane-like, shrub-like, rhizomatous, semperflorens, trailing-scandent, thick-stemmed, rex and tuberous. It's beyond this post to explain the intricacies of begonia classification but for most the names are relatively self explanatory.

The rex bogonias, are perhaps not, and they are all cultivars of one species, Begonia rex, a rhizomatous species (i.e. spreading by underground stem - a rhizome) from the state of Assam in India. The wild species has green leaves with silver banding, I think, but as I saw in the extensive display in Bentleigh, the cultivars now grown have leaves of green to grey to deepest claret and purple. The leaf colour range has been compared with precious metals, and the texture with exotic fabrics.

We grew a couple of rex begonias in our front garden in Sydney, under a tree, where they more or less thrived. Here in Melbourne you'd need a glasshouse, or fish tank.

You can grow quite a few begonias outdoors in Sydney but further south (and up the mountains) it's often best to grow them in pots and protect them from frosts and very cold winters. That said, here in Melbourne the climate may be coming more conducive to growing begonias outdoors.

The best known begonias are probably the tuberous ones bred to produce big blousy flowers, of the kind you might find in the Ballarat Botanical Gardens. These you will find grown and displayed in a glasshouse.

What all begonias share are asymmetrical leaves, as in this picture of the (non-rex) Begonia boliviensis I took home from the meeting in Bentleigh.

In addition to being one of the species grown by Guilfoyle it is also from Bolivia, so I can add it to my Talking Plants list of plants from that oddly romantic country. It's a tuberous species from the cold peaks of the Andes, but happily adapts to gardens in Sydney and Melbourne, producing lovely summer flowers.

Begonias have either male or female flowers, both on the same plant, and as you can see the male flowers are quite open in this species so you can see the pretty anthers ready to release their pollen.

For now the pot sits at my front door. A reminder for when we build a glasshouse at the Royal Botanic Gardens: remember Guilfoyle, Bolivia and...oh, yes...begonias.

*Thanks Peter Moonlight for advice on nomenclature. And look out for a full census of Begonia species, coming soon according to Peter! 

Tuesday, 24 February 2015

Misplaced (and edible) hat plant

It takes six leaves from the Panama Hat Plant to make a Panama Hat. The leaves must be young and most commonly they will come from the country of Ecuador. Never or rarely, I gather, from Panama, where the hats were first traded in the nineteenth century.

The Panama Hat Plant looks like a palm. Indeed it is sometimes called the Jipijapa Palm, after one of the Ecuadorian towns that makes the hats. But it's not a palm. Botanists have always know that. In fact these days we consider it even less of one!

Carludovica palmata has always had its own family, Cyclanthaceae, but this used to be tucked in near the palm family Arecaceae, albeit each within its own order (Cyclanthales and Arecales). The Pandanas family, Pandanaceae, used to be thereabouts, again in its own order (Pandanales).

Nowadays our Panama Hat Plant is included within the Pandanales, closer to Pandanas but distant now from the true palms which are clustered elsewhere in the family tree with grasses, gingers and the water hyacinth (in a group called the Commelinids).

To look at though, the fronds look very palm-like. The one-metre wide leaves are fan-shaped, divided into three to five segments, with each segment further divided towards the tips.Unlike all fan palms, however, it doesn't produce a trunk.

The flowers arise from the base of the plant, on a stalk and grouped in a cylindrical 'spike'. As with cycads, an very unrelated group of plants, weevils pollinate the flowers.

The Panama Hat Plant is a tropical species, growing naturally from Mexico to Bolivia, but more commonly in Ecuador. In Australia it grows outdoors in Sydney and Brisbane botanic gardens, but apparently not here in Melbourne. There are three other species in the genus Carludovica, all with similar horticultural requirements.

Apart from spiffing hats, the leaves are used for 'matting, curtains, roofing, baskets, cigar-cases, purses, fly swatters and brooms'. In fact anything that needs a tough, weavable fibre, including mammal and fish traps.

In Ecuador the base of the unopened leaf base tastes similar, apparently, to a palm heart. This may be a more sustainable way to satiate that particular food fetish given that extracting the heart - the growing point - of a palm kills it.

I just need to wait until this specimen on a colleague's windowsill matures a little, then creep in and do some (sustainable) harvesting.

Image: a photo by Lynda of me with my then new Panama Hat, in London in 2012. The window sill seedling is from the office of Frank Udovicic, at the Royal Botanic Gardens Melbourne, who drew this plant to my attention. The picture of the mature plant is by Bill Baker, from Royal Botanic Gardens Kew, taken inside the Palm House at Kew Gardens by the looks of it.

Tuesday, 17 February 2015

Wiping the glaucous sheen off a Pig's Ear

In early January I kayaked past this plant spreading up, or down, the banks of the Yarra River. Then a little later in the same day, walked past it in jutting from a rock wall, leaves sheening in the brilliant midday summer sun.

It's not a plant you can kayak or walk past easily, particularly when in flower. Cotyledon orbiculata, more commonly called Pig's Ear, is grey with a glaucous sheen, almost all over. The exceptions are the edges of the leaves, which are red, and the inside of the flowers, which in this case are orange to appeal to sunbirds.

Pig's Ear flowers mostly in winter but where there is more winter rainfall, such as the Western Cape (and here in Melbourne), in midsummer. Presumably the African sunbirds know when to be active.

According to Shireen Harris on the PlantzAfrica site, there are 10 species of Cotyledon, a genus name based on the Greek work kotyledon meaning cup-shaped hollow (and also used for what are called the seed-leaves of most flowering plants, the cotyledons).

The leaves of most species, including Cotyledon orbiculata, are cotyledon-like in shape.

The waxy white coating reflects the sun's heat, to prevent overheating and water loss. In low light, little wax is produced, in high light (such as on this rock wall), lots. When fully coated, up to 50% of the sunlight reaching the plant surface can be reflected and water loss reduced.

If you remove the coating, as I did here with my finger, it will take about two weeks to start returning again on that leaf. The waxy deposits are formed inside the leaf cells and exuded to the outside during growth and after injury. It seems that the route to the surface, and the means of production, do not shut down once the leaf is mature.

(I did a slightly more thorough test  on a smaller plant we are growing at home, wiping strips from two differently aged leaves to see what would happen. After two weeks a light cover of wax had returned on both, and now, just over six weeks later, the coating is thick enough to make the strip look grey rather than green, It's still noticeable though and I wonder if it ever completely recovers its full coating.)

I doubt that in the Australian summer my interference will cause the plant, or even this leaf, to die (the cuticle, a more important waxy-outer-layer on nearly all leaves, did survive my vandalism), but is a shame to do it more often than you need to in the interests of curiosity. If for no other reason, it detracts from the beauty of the plant as a whole.

In their southern African homeland, in rocky outcrops, the plant may well be more finely tuned. One poorly performing leaf could be the difference between living and flowering, or death. Perhaps. 

For me now, there are those complex feelings after you have done some thing you really shouldn't have. I know this leaf will recover its wax but will it be in time to survive the summer? I'm not sure if it matters, given the small surface I scraped, but I do add it (along with memories of insects I've squashed, birthdays I've forgotten and chances of selfless assistance to others) to my life-time load of guilt.

But then, in Australia Pig's Ear has escaped from gardens and is spreading through bushland areas, such as the Yarra River verge near my home. If I were to think instead about the potential of this plant to jump the garden fence and spread further into native vegetation, displacing indigenous plants and animals, I could convince myself this was a (very) small contribution to conserving Australia's biodiversity.

But that would be stretching things a little (a lot). And unfair to my neighbour's garden.

Images: all from the plants growing out of the rock wall in a nearby street. 

Tuesday, 10 February 2015

Saint-Catherine's Lace covers giant island-plant

In early January I took these pictures of a striking plant among the rocks in our Californian Garden. There is another on the way into the Royal Botanic Gardens at Observatory Gate, and it was featured on the Gardens' Facebook page on 30 January. It's a rare plant called Saint Catherine's Lace, growing naturally in the Channel Islands 150 kilometres west of Los Angeles.

The Channel Islands include three large islands (plus some smaller outcrops), each with its own variety of Saint Catherine's Lace (Eriogonum giganteum). I gather this species (and its three varieties) is native only to the islands of Santa Barbara, San Clemente and Santa Catalina but you sometimes see its distribution represented as far wider in California, extending along the mainland coast from the Mexican border up to about San Francisco. I'm presuming these are naturalised records given it is so widely grown in gardens throughout the state.

Also called the Giant Buckwheat, it can grow to two metres high, and across. The Catalina Island Conservancy cites Saint Catherine's Lace/Giant Buckwheat as an example of island-induced gigantism. That is, islands acting as discrete evolutionary laboratories where plants often become unusually large, or small.

These islands are hot and dry and Saint Catherine's Lace needs little water to survive in Melbourne. It flowers over a couple of months (attracting lots of insects and birds) and looks attractive in woolly leaf for the rest of the year. Sounds like a plant that should be grown more often, particularly as our summers become hotter and our rainfall less reliable.

Just watch it though. In Californian gardens it seeds readily and self sows, so do make sure it doesn't spread beyond your garden. At the moment is so rare in cultivation that its potential to spread is probably untested. (It also has a propensity to hybridise with other species of Eriogonum but as we have no native representatives in Australia that shouldn't be a concern.)

The buckwheat we consume as a grain, by the way, is another species in the same family (Polygonaceae) called Fagopyrum esculentum. As you might have guessed, it's a smaller plant, as are other species of Eriogonum also bearing the common name Buckwheat (or more often, Wild Buckwheat). 

All these buckwheats are unrelated to wheat (a species of Triticum, and a kind of 'grass'), which accounts for the absence of gluten in their grain, making at least Fagopyrum esculentum flour a rather popular substitute for wheat flour in bread and pasta.

You could also be mistaken for thinking our plant was in the carrot family. The flowering structures (below) certainly resemble things like Queen's Anne Lace in the family Apiaceae.

As to Saint Catherine, I think she is the Catholic saint and Princess from Alexandria. She is often portrayed in paintings wearing quite elaborate garb, leading I presume to the reference to her lace*.

In mature bushes the lacework of flowers can almost completely cover the whole bush, as in this shapely specimen from the California Native Garden at Golden West College, California. This is something for us to aim for in our Californian Garden.

Images: The picture from Golden West College is from their website.

*This intriguing and slightly gruesome comment added to the blog might is a likely explanation: 

lena.m said...
Saint Catherine, princess of Alexandria, was martyred for her purity , wisdom, and persuasive powers, by being bound to a wheel where upon her limbs were to be broken, but the wheel fractured, and she was decapitated. Hence the Catherine Wheel fireworks, and white for the purity represented by her name.

Tuesday, 3 February 2015

Yuck, ah, not

What used to be called Yucca whipplei is a popular landscape plant in Melbourne's Royal Botanic Gardens. The pin-cushion clumps are ultra-neat and pastel-grey in colour. They fit nicely into our Californian Garden because that's where they hail from (south-western North America), and in our Guilfoyle's Volcano collection (pictured here) due to their succulence and tolerance of dry conditions.

Also called Our Lord's Candle, this yucca is now in a separate, less memorably named, genus, Hesperoyucca. There are two species, one named after Mr Amiel Whipple, the other after Mr John Newberry. Ours is therefore now Hesperoyucca whipplei.

The 'hespero' part of the genus name presumably refers to their western distribution in North America, and they differ from the rest of the yucca cohort in subtle details of their flowers and fruits. The leaves clasping the flower (bracts) are usually bent backwards and the receptive part of the female structure (the stigma) is 'head-shaped' rather than with three lobes (each sometimes split in two) as in Yucca. (The stalk supporting the flowers and fruits is also wider in Hesperoyucca than in Yucca.)

None of ours are in flower at the moment so here is what they don't look like! These are images I took of a Yucca (not Hesperoyucca) flowering in a street near my home. Note too the very cool anthers, looking like pipe cleaners tipped with a blob of gold paint (the pollen).

I got excited a few weeks ago when a succulent which seemed to be labelled as Hesperoyucca started to flower in the California Bed. It produced a massive flowering stalk, much bigger than I was expecting. And that because it was an agave (same family but quite different). The Hersperoyucca whipplei had died recently, so the sign seemed to the untrained eye (sigh) to refer to the next door agave. Clearly a lapse in my botanical logic given the agave had whopping great thick leaves and the flower-buds were, not surprisingly, starting to look more like an agave than a yucca...

So you don't get any pictures of the Hesperoyucca flowers I'm afraid. Or any discussion about what, if any, variant of Hersperoyucca whipplei we might be growing. Sometimes Hesperoyucca whipplei is split up further into subspecies or varieties based on the way they produce 'offsets' (the plants that bud off at the base, surviving the death of the main clump after flowering) and the size of clump and flower spike.

I'm not sure where to go with the common name Our Lord's Candle. I'm tempted to say I won't touch it. Instead let me tell you it refers to the candle-like flowering structure, with hundreds of white typical-yucca-like flowers.

The flower-less plant is pretty enough, but do take care. Each leaf is terminated by a sharp pungent point. The finely toothed margins (which you can almost make out in this next photograph if you squint a little) you needn't worry about. At most they gently massage your finger-tips.

Each cushion takes about five or more years to flower, then like the agave (in the same family and subfamily) it dies, with off-shoots from the base taking over to run through the same cycle again. In its native California a moth pollinates the flowers at night, contributing a small moth egg as well as pollen to the receptive flower. This egg grows into a larva that will eat some, but not all, of the seed.

Here in Melbourne, without the moth, we may not have any problem with caterpillars eating our seed, but then we may also not get any seed. Which, according to this sign, means ropes, nets, baskets and soap, but no flour.

Tuesday, 27 January 2015

Eel heads and floating flowers

All seems calm at the Ornamental Lake in Melbourne's Royal Botanic Garden. It's a wintery morning before a hot summer's day in late January. Fairly typical weather for this city.

There are a few (sub)tropical trees still flowering but the Jacarandas, Brachychitons and Cape Chestnuts have finished. Recent rain has kept the Gardens green but you can sense that things are about to curl and brown, with most plants shutting down for the summer.

In the lake itself there is plenty of algae, mostly submerged clumps of a green alga called Spirogyra, which do from time to time float to the top. The Purple Loosestrife (Lythrum salicaria) continues to do what it does best on the floating islands - bloom, bloom and then bloom some more.

In front of this floating wall of grass and loosestrife you can see mats of algal and aquatic plants accumulating at this north-east corner of the lake. The dominant aquatic plant is Eelgrass, Vallisneria australis, a Victorian native that extends all the way up to near the Queensland-New South Wales border. There are seven or so species of Vallisneria in Australia, mostly tropical, and mostly with long ribbon-like leaves - hence the common name.

For most of the year you can just ignore it. Eelgrass is there, doing all kinds of good things in the lake in terms of habitat and nutrient recycling, but for you and I its a case of move along, nothing to see here.

But in late January something does happen. The first thing you might notice are tiny eel heads poking up out of the water. I say eel* heads but that's just me being poetic and metaphoric. These are the, by the time I got to see them 'spent', female flowers.

The next thing you (might) notice is an intricate lacework of white fluff. These are the male flowers.

As you will have gathered, this is a plant with single-sex flowers. That's not unusual per se in the plant world but the way these flowers work is. Eelgrass has a particular method of pollination called, entirely unhelpfully, ‘Type III’. It's only found in Vallisneria and other members of its family Hydrocharitaceae.

The key feature is the complete detachment of male flowers as buds from a sheathed stalk at the base of the plant. These tiny flowers float to the surface where they open fully and then coagulate together in floating rafts, drifting around with the wind and current.

There are minor variations to 'Type III' pollination, and in Eelgrass and two other related genera, the pollen has to remain dry. So the flowers actually float so that the pollen bearing bits are held aloft, above the water! You see them here hovering around a slightly submerged eel head, a flower already fertilised and having lost its petals (and sepals).

The receptive part of the female flower (the style) also has to remain dry, before fertilisation. At first the style is protected by the tightly wrapped petals (and sepals). By the time the flower opens, its long flexible stalk has extended it through the water surface. There it eventually comes in contact with the drifting male flowers and fertilisation takes place.

All the female flowers I saw and photographed were fertilised and beginning to set seed. After pollination the stalk of the female flower becomes spiralled, dragging the developing fruit underwater. The seed are eventually released in the murk beneath, to be washed around and settle somewhere new.

Yes really. That's what is going on in and on the lake while the rest of the garden is bunkering down for late summer.

* As our website boasts, the Ornamental Lake is home to a healthy population of Short-finned Eels (Anguilla australis). These eels live hereabouts before the arrival of Europeans, and they enjoy the moderately shallow parts of the lake where they feed on crustaceans, frogs, insects and worms. So much so that they can reach 1.3 metres long. Eventually though they swim and slither their way into coastal estuaries where they swim 4,000 km to spawning grounds in the South Coral Sea. Because eels can breathe through their mucus-coated skin, they can in fact slither overland when it's damp (e.g. at night). At breeding time the mature eels are drawn towards flowing water, and find their way through drains to the Yarra River. The leaf-shaped larvae (soon becoming what we call 'glass eels') hatch off New Caledonia and are carried southwards on ocean currents, until at the age of one to three years when they (now 'elvers') migrate up Victorian rivers and streams, until some call our Ornamental Lake home. 

[Thanks to Neville Walsh for directing my attention to the curious botanical phenomenon.]

Tuesday, 20 January 2015

The sweet aftertaste of artichoke

There are lots of phenolics in Globe Artichokes. To be fair, there are lots of phenolics in the plant kingdom more generally. Phenolics are, in chemical terms, compounds with one or more of what chemists like to call 'aromatic rings' and with one or more of what chemists like to call 'hydroxyl groups'.

[The simplest aromatic ring is the one with six carbons and six hydrogens, drawn as a hexagon with every second side with a double line. A hydroxyl group is represented as an O (oxygen) with an H (hydrogen) sticking off one side and the hexagon or something similar off the other.]

Phenolics are produced by most plants as secondary metabolites, that is products not used directly for growth or reproduction, but for things like protection against pests, against excess radiation or add colour to various plant parts. So far we know of 8,000 different phenolic compounds in plants.

Phenolics add some of the more interesting flavours to fruit and vegetables, such as the bitterness and astringency of berries, and give tea, coffee, beer and wine their kick.

One of the phenolics in the Globe Artichoke is called cynarin. It inhibits taste buds that detect sweetness. And as you eat other things afterwards, the cynarin layer in your mouth is gradually removed making everything suddenly seem very sweet. Miraculin does the same thing in the so-called Miracle Fruit.

To test this I went to my local shops to find a fresh Globe Artichoke. Sadly, none to be found. So I thought I'd test a grilled and pickled version, to see if the phenolics survive all that processing.

Turns out they don't. At least in the one I tasted and then followed by a lime. I ventured further afield and eventually found some fresh artichokes (below) which when eaten after boiling caused water to taste a little sweet (although the sweetness emerged a few minutes later) and very slightly made a lemon seem less sour (not exactly sweet, although again, a few minutes later I could taste sweetened lemon in my mouth). Not quite as miraculous as Synsepalum dulcificum, but a little bit fun.

By the way, the artichoke I'm talking about here is the Globe Artichoke, a thistle, Cynara cardunculus (you can see where the phenolic name comes from). The Jerusalem Artichoke, Helianthus tuberosus, illustrated below, is also in the daisy family but not a thistle and more closely related to the Sunflower (Helianthus annuus). And of course rather than the flower head, you eat this, the tuber.

And not all Cynara cardunculus are Globe Artichokes. While there is some debate over what names to use, there are usually two subspecies recognised, one for the Globe Artichoke, the other the Cardoon (it again is usually divided into two varieties, the cultivated and the wild Cardoon).

The Cardoon is also eaten, and was described recently as 'a fantasy dragon of a vegetable: what celery would look like it went through the Looking Glass and ended up in the Game of Thrones' (do check out the photograph in this link - you'll soon get the idea). They taste a bit like artichokes but you eat the stem rather than the heart of the flower head.

 Thanks to Janet O'Hehir who many months ago mentioned this characteristic of the Globe Artichoke to me after I wrote about the Miracle Fruit. And the beautiful drawing of an artichoke, Cynara cardunculus var. fortissima, is by Debra Bartlett. It was bought last year by the Royal Botanic Gardens Melbourne Director's Circle for the State Botanical Collection, and resides at the moment on the wall in my office. (I can't track down this varietal name but presume it is a Globe Artichoke.) The flowers photographed are in front of the Alpine House at Kew Gardens in 2011.

Tuesday, 13 January 2015

The simple enjoyment of an orange, green alga

I've mentioned these orange cushions in passing a couple of times but the organism responsible for them is worth a little more attention. While it's an alga rather than a plant, in the evolutionary tree of life it's in the branch that splits off just below the green plants - so not too distantly related.

It's called Trentepohlia and you can find it on rocks or wood, in pretty much any part of the world. In Victoria (Australia), drive from Halls Gap to the Zumsteins, through the Grampians/Gariwerd National Park, and you'll see a lot of it on the roadside at slightly higher elevations.

Here on a rock wall in a village in the West Pinines, an hour or so from Durham in northern England, it thrives. There are about 40 species and this one is probably Trentepohlia aurea, a common species in these parts (although it may be applied more commonly than it actually occurs given the lack of recent taxonomic work on this group - studies by Mike Guiry and colleagues are the exception).

Although it is orange in colour, it is classified as a green alga. And if you look under a microscope you'll see that it is fundamentally green overlaid with an orange pigment, called haematochrome. In this picture the green dominates but sometimes it's all orange, orange, orange...

It's thought that the haematochrome helps protect the alga in the very exposed places it finds to live - out of water, on walls, often in full sun.

Sometimes it might be confused with various red or orange lichens such as those found on coastal rocks in Australia and elsewhere. It might also look like a clapped out moss I guess. A quick peak under the microscope will confirm it's identity but generally if in the field it is orange in colour and velvety in texture it's likely to a Trentepohlia. (Although be aware that this alga also finds it's way into the algal-fungal symbiosis we call a lichen.)

The UK wall featured here is said to be the densest and most extensive population of this alga in England. I have no way of testing that but other patches I saw were certainly smaller and the local community is justly proud of its orange wall. The habitat must suit it, and the wall would be old enough for this alga to have grown to such an extent (Trentepohlia is often described as growing 'very slowly' and I would expect it would take many decades or centuries to achieve this result).

Interestingly other walls nearby support mosses and lichens, due to either microclimate, or age and disturbance I suppose.

None of these growths will particularly harm the wall and when Trentepohlia grows on tree trunks it doesn't cause any damage. Another genus of algae in the same family (Trentepohliaceae) called Cephaleuros is less popular because it can become parasitic on tropical crops such as cocoa and tea, leading to extensive foliage damage.

Trentepohlia, like most algae, is simply there to be enjoyed.

Images: from my trip to Durham (skyline below...) in July last year, except for the microscope picture which I have copied from the University of Wisconsin Madison, Botany 330, Algae webpages.

Tuesday, 6 January 2015

Nick's Lime Tree (Plant Portrait XI*)

On 20 December 2014, musician and writer Nick Cave planted a lime tree on Picnic Point, beside the Ornamental Lake, in Royal Botanic Gardens Melbourne. It was our 103rd commemorative planting, and the first for over a century that didn't involve a governor general, governor, queen, duke, countess, marquis...(you get the idea)...or associate of the botanic gardens.

Even then, in the early twentieth century, there were usually links to title. Opera singer Nellie Melba was a Dame when she planted a Poplar (Populus) in 1903, which has since died, and the pianist and composer Ignacy Paderewski was the third Prime Minister of Poland when in 1904 he planted a Buckeye (Aesculus), still living.  

We have a plan now to celebrate people associated with Melbourne who have made a major contribution to the cultural life of Australia and beyond, with or without honorifics. Names on our list include Ron Barrassi, Cate Blanchett, Nick Cave, Barry Humphries, Michael Leunig and Geoffrey Rush (at the moment the gender balance is a bit like the first Federal Coalition Cabinet).

Many Melburnians of my age have grown up, or not, with Nick Cave (pictured here in the Royal Botanic Gardens with a mature Lime Tree). His music has been, almost literally, the soundtrack to our lives: from the The Boys Next Door/The Birthday Party's Mr Clarinet and Zoo Music Girl at student parties or live at the Prince of Wales in St Kilda, through the bands Bad Seeds and Grinderman, to recent musical masterpieces such as Higgs Boson Blues. Along the way there were films, books and other collected materials.  

Nick Cave started performing in Melbourne but soon became a musician of the world, and resident of Germany, Brazil and now the UK. His lyrics and novels have been the subject of workshops and academic scrutiny. Earlier this year Gerard Elson, in the magazine Island, compared him to Bob Dylan, Leonard Cohen and the American poet John Berryman. In The Monthly, Robert Forster places Nick Cave at the top of his list of Australian 'rock stars', ever.

Nick's writing and music is by any standard clever, evocative and fun. At its peak it's goose-bumps inducing, whether mellow or murderous. While there are plenty of plant references dotted through Nick’s lyrics - he was perhaps the first Australian 'rock' artist to reference nature in this songs - the selection of tree planters is not about plants, and mostly it never has been. It's part of the Royal Botanic Gardens celebrating its place in the cultural life of Melbourne, as well as attracting visitors to a place (for whatever reason) so we can drench them in the beauty and importance of plants.

Nick Cave's significant contribution to art and to Melbourne make him an obvious first choice in this reinventing of the commemorative tree planting program. While others on the list may be better known, we felt it was important with this first choice to pick someone less conventional and a little provocative. Someone who has extended the culture of Melbourne geographically and creatively. Someone who reflects modern Melbourne.

We won't rush the next planting and I expect we'll do one or two a year. I like the idea of linking the tree, at least tangentially, to the person doing the planting but it needs to be a tree we want and to fit into the Gardens landscape.  

The tree this time is a Lime, a connection to one of Nick's most moving songs where he says 'I put my hand over hers, down in the Lime Tree Arbour'. This particular lime is called Henry's Lime, Tilia henryana, again a nod to one of Nick's creations, the 1992 album Henry's Dream. 

This is the first time we've grown Tilia henryana. It's an Ernest Wilson collected species from China, introduced to the West around 1901 and named after another prolific plant collector, Augustine Henry. The leaves are described as 'sea-green' when mature, glossy above and silvery below. But the new leaves, which you can see now (and pictured at the top of the post), are silvery-pink or copper-coloured, and produced in mid to late summer as well as spring.

So this flush of growth is expected, although perhaps not the best thing to do this time of year in Australia. In his recent book on Henry, Seamus O'Brien describes this species as 'the largest of all the lime trees from western and central China, and without a doubt the most beautiful'.

Thanks Nick. Not quite a Lime Tree Arbour, but a beautiful Henry’s Lime to celebrate a major contribution to world culture, from Melbourne.

Notes: I held back on posting this story having already pasted most of the photos in my Facebook page, and with the Sunday Age running a photo story the day after, but the tree is doing so well, and the new growth is so pretty, I can't resist.