Tuesday 2 October 2018

Something Fishy

Take a whiff

Some say flowers are how the Earth smiles. Bright, colourful blooms on all different levels, from down low to up high, they certainly do a great job of making themselves known. From the obvious to the conspicuous, they are beautiful in a variety of ways.

Flowers play a big part in how plants function. From how they are grouped and classified, to how they aid the procreation of the species. These intricate and unique appendages capture not just human imagination but the attention of birds, animals and inspects as well.

They have evolved over many years to take advantage of their environment. More than just a bees buzzing happily from flower to flower, some plants have developed interesting ways to ensure pollination occurs.

From the imitators, the flowers that mimic prey, food or perhaps a mate, to those that use mechanical methods to paint or trap a pollinator into ensuring genetic material is passed from male to female flowers so plant reproduction begins (but is not always guaranteed of course).

William Shakespeare famously penned "A rose by any other name would smell as sweet" for one of his most famous works 'Romeo and Juliet'. I have been inspired by Mr. Shakespeare and have come up with a little poem that helps introduce my latest blog:

Roses are Red
Violets are Blue
Some of the flowers below
Smell like Poo

I bet ol' Bill wouldn't be able to write the same thing about The Corpse Flower or Dead Horse Lily. Not all of God's flowery children have a heavenly scent, some are down right disgusting. Being that it's now Spring in Australia, I thought it would be great time to look at some of the plants that aren't so pleasant to the nose.

Pepe Le Poo! The Skunk Cabbage


First cab off the rank is the aptly named Western Skunk Cabbage or Lysichiton  americanus. This American Native grows predominately in the Pacific Northwest in boggy marshes. It was imported into the UK as a ornamental plant and has subsequently naturalised in damp areas.

Part of the Aracea or Arum Family, which consists of over 3,700 species, it bears the distinctive spadix flower common to the family surrounded by a bright yellow spathe or leave like bract, that almost fully encloses the spadix. Flowers emerge in Late Winter and Early Spring. 

The plant gets it's name from the 'skunky' odour the flower produces when it opens. The smell can be detected fairly easily and can even linger in dried, spent flowers. The odour emitted attracts scavenging type flies and beetles as pollinators.

Although mostly considered a bit of a weed, the roots are food for bears waking up from hibernation, for them it has a laxative and cathartic effect, just what you need after a long sleep and you're feeling backed up. Indigenous Americans used the plant as treatment for injuries and burns. The big, waxy leaves were also useful for lining their baskets.


Nothing to do with sauce - the Dead Horse flower

The common name of our second guest just makes you want to run out to the local nursery and buy it,! The aptly named Dead Horse flower or Hedicodiceros muscivorus conjures up images that make you a little queasy in the stomach. Another member of the Araceae family, it is native to Corsica, Sardinia and The Balearic Islands in the Mediterranean.

It's fowl smelling flower produces an odour resembling rotten flesh and attracts carrion (the decaying flesh of dead animals) blow flies. The flower contains both male and female parts but each do not become mature at the same time, to reduce the chance of self-pollination and in breeding.

Flowers trap the curious flies already covered with pollen from other flowers, they then coat the females parts as they make their way to the lower flower chamber. By the time the male parts are mature, the flower opens allowing the flies to pass through the entrance (where the male florets are located), coating them with pollen before they fly off to visit another flower.

It has an interesting ability of being able to raise the temperature of the flower to increase the potency of the scent given off. Botanists are still trying to figure out how it is able to increase it's own temperature without necessarily relying on the temperature of the surrounding environment.


Real star power

The next group of plants are succulents know as the Carrion Flower (more decaying flesh I hear you say). Stapelia are a group of spineless stemmed succulents, mostly endemic to South Africa.

If they look familiar, you probably have seen them amongst house plants on verandas of elderly relatives, yep - it's a bit of a grandma plant, a real throw back to the 70's. The Carrion Flowers became popular with indoor gardeners due to their unusual flower and stem shapes and of course, their ease of care.

Their particular odour is attractive and deceptive to blow flies, who lay their eggs around the inner parts of the flower, convinced that the flower is indeed rotting flesh.

Stapelia sp. are still fairly popular today with succulent collectors, so they aren't too hard to find through retail nurseries and local market stalls.


It began in Africa.

Our next special guest is the Hydnora africana. This funny looking plant is achlorophyllous, meaning it cannot photosynthesise, that is produce energy from sunlight. Instead this fungi looking plant is parasitic, capable of "borrowing" its food requirements from another host plant.

H. africana or Jackal Food as it's sometimes referred to, contains an enzyme that can dissolve plant roots allowing it to attach to it's host, which are plants from the Euphorbia family. The plant grows totally underground, except for the fleshly flowers (see photo above), that can take up to two years to fully ripen, that emerge after heavy rains ("down in Africa....").

The flowers literally smells like sh*t, hence why dung beetles and other insects are so attracted to them. These insects bury themselves in flower bodies, becoming stuck and can be there for up to two days before they are released to pollinate other flowers. Pollinated flowers can produce up to 20,000 seeds.

Aside from the stink, the flowers produce fruit that have a similar texture and taste to potatoes. The fruit also has been used for tanning and preserving fishnets of African tribes. Fruit produced is also a food source for many native African animals.


Another smelly flower? Of Corpse!

Next up is a plant who has a rather large flower, in fact it produces the largest individual flower on earth, so it's both easy to see and smell! The Rafflessia arnoldii is native to the rainforest's of Sumatra and Borneo. It's another parasitic plant, relying vines also endemic to the areas it grows in.

The flowers of the Corpse Lily have a diameter up to 105cm and have weighed in at a hefty 11kg. The largest recorded specimen measured 43cm wide. Also producing an aroma of rotting flesh, the flowers of the Rafflessia are the only distinguishable parts of the plant.

They produce no real leaves, stems or roots but are still considered a vascular plants (those having tissues for conducting the flow of water and minerals throughout the plant). Flower buds (that can be up to 30cm wide) take months to develop and open. The Corpse Lily are fairly rare and difficult to locate not only in cultivation but in the wild.

The curiosity factor has been both a help and hindrance to R. arnoldii - on one hand the attraction has increased tourism to areas where the plants grow. However, the downside to increased tourism has exposed the species to pressures from humans, to a point where species numbers are decreasing.

Environmental scientists are trying to recreate the specialised environment in a bid to encourage population growth with no real success so far. Local governments have encouraged private land holders to conserve and protect specimens on their and even charge small fees for people to see them.


A real titan of the botanical world.

The next contestant needs no introduction as it has been a consistent celebrity in the garden world. The Titan Arum or Amorphallus titanum annually makes appearances on TV and newspapers as reports from Botanical Gardens around the world await the giant flower to open.

Hailing solely from rainforest's of Western Sumatra and Western Java it has been a fascination in the botanical word since it was first recorded in 1787. It is a curiosity due to the fact it infrequently flowers in the wild and even less in cultivation, so when it starts to it almost always makes headlines. Today there are five blooming events worldwide due to the increased number of plants being cultivated in Botanical Gardens and private collections.

A. titanum grows from a corm (a bulb like structure) for which it is the largest known, weighing on average 50kg, but other corms around the world have been weighed in excess of 100kg, the current record is 153.9kg held by the Edinburgh Botanical Gardens.

The Titan Arum is also famous for having the tallest, unbranched flower inflorescence in the world. Standing at 3m it is quite impressive when in full bloom, then there's the smell...
It produces a smell conducive of rotting flesh to attract carrion eating beetles and flies that help to pollinate it. At the height of it's bloom, the inflorescence's temperature is roughly the same as the average human body.

Much like it's cousins in the Aracea family, it has both male and female flower parts that mature at different times to reduce the chance of self-pollination. Flowers don't come around often and need at least 7 years of vegetative plant growth before blooms are produced. After the flower dies back, a single leaf is produced reaching around 6m tall, it dies and another replaces it. The process is repeated until the corm has stored enough energy to begin the blooming process.

The Titan Arum was first cultivated at the Royal Botanical Gardens in Kew in 1889, they have had over 100 cultivated blossoms since then. In June 2010 the largest recorded inflorescence was acknowledged by people at Guinness World Records, standing at 3.1m tall the specimen belonged to a private collector from the United States.


Compare the Pear

Now to our final specimen. This particular plant breaks the current trend and doesn't smell like rotting flesh. It's smell is not hard to define for those who know the tree well enough, for those who don't how can I put it? Somewhere between stale milk and a teenage boys room perhaps?

I speak of the humble and still very popular ornamental pear. In particular the P. calleryana and it's varieties such as 'Bradford', 'Chanticleer' and 'Capital' - which have a more uniform and narrow form suited to home gardens or streets. They are 'ornamental' as they don't produce fruit and are used for foliage and flowers.

Callery Pears are still widely used in the Australian landscape industry for it's broad canopy, the red and orange autumn colour and of course it's clusters of white flowers that are produced prior to leaf set. Let's take a closer sniff at these flowers shall we?

In the horticultural world, the description of the smell these flowers give off is cause for a laugh. Even those who don't know the name of these trees can at least describe the smell fairly accurately. These Pyrus flowers not only signal that Spring is here but are also probably the reason why your street or nearby park smells like semen right now! That's right - cum, jizz, spooge or dozens other names it goes by, but you get the picture or is that scent?

If it's a particularly warm start to spring and the breeze is about, more than likely you'll have experienced the "Pyrus effect" and it's OK to have a giggle, don't feel juvenile or dirty, it's just Mother Nature's way to indicate life anew is in the air.

So I hope I have shed some light (or smell) on an odd and unique group of plants, cause it's not all sweet and fruity out there people. I totally agree, take time to smell the roses, but you may want to give a second thought to the fore mentioned plants and give them a wide birth! Or at least take a peg for your nose.