Behind the art works – the Cordyline Palm

cordyline-australis

Before the team and I decided on which trees to include in our project we visited the various trees on the Trinity College campus. Personally I was drawn time and time again to the mesmerising swaying of the flexible tree branches and the soft meditative swishing sound created by the wind rustling through the leaves of the Cordyline Palm. In the end we decided to include the palm tree with it’s multiple branches growing closely together from the base as a counterpoint to the size and stocky nature of the other trees, which have a single trunk and many branches. I knew from very early on that any artwork I would make would have to reference the delicate appearance of this tree while also referencing it’s very specific physiology.

As I thought further and researched more about the palm tree I was reminded of a two week holiday I took in Bali over ten years ago. Each day I encountered numerous offerings left outside houses, on pathways and in the temples by the locals. Each parcel was simple yet beautiful created using banana or palm leaves and filled with rice and colourful flowers.  See images above.

More importantly I was very lucky to be in Bali around the time of the Galungan festival. Galungan marks the beginning of the most important recurring religious ceremonies in Bali. The spirits of deceased relatives who have died and been cremated return to visit their former homes, and the current inhabitants have a responsibility to be hospitable through prayers and offerings. The most obvious sign of the celebrations are the Penjor – bamboo poles with offerings suspended at the end. Every street is lined with Penjors outside each house one more decorative than the next.

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The main material needed to make a Penjor is a long, curved bamboo pole. The pole is then decorated with coconut leaves and various other natural items. At the end of each Penjor a decorative Sampian is hung made with coconut or palm leaves and flowers.

I remember at the time being captivated by the amazing diversity of shape and texture the Balinese could create with such a simple materials.

For the Trinity College Trees project I decided to create a Penjor of sorts to represent the Cordyline palm. Its strength and flexibility alongside it’s delicate appearance is the perfect vessel to embody the nature of this tree.

When I made this initial decision a few months ago I collected a large black bin bag full of fallen Cordyline Palm leaves from Trinity College. I worked with the leaves, curving and shaping them over a few weeks. The colour of the leaves for me was an issue, the natural brown didn’t really fit with the chosen colour aesthetic. I tried painting the leaves with bright neon acrylic paints but the result looked forced.

I abandoned the palm leaves and decided to cover the curved bamboo pole with neon orange ribbon and create my own decorative elements with an electric blue fabric.

The shapes of these elements were chosen based on some of the SEM images of the internal cellular structure of the Palm. David Hackett kindly explained that the Cordyline Palm is a monocot. This didn’t mean much to me initially but now I understand it that a monocot, as the name suggests, has one ‘cot’ or cotyledon. A cotyledon is basically the first leaf that sprouts from a seed. Monocots have one, and dicots have two. Basically some plants have one leaf to start their lives out with, and some have a pair.

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left: monocot, right: dicot

The reason I mention this is that I was interested in how the cellular structure of the Palm (as a monocot) looked and differed functionally to all the other trees in the project, which are dicots. As you can see in the SEM image below of a cross section of the parallel veins of the palm they are laid out in bundles, which are then arranged together to create the internal cellular structure of the branch.

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I used the various shapes from these bundles to create the decorative elements of the Penjor. Imagery from the cross section of the veins in the bundles were recreated by drawing in neon orange acrylic paint on the blue fabric sections. Finally I will draw on imagery of the breathing hole (soma) from the underside of the palm leaf while creating the decorative Sampian at the end of the bamboo pole.  See images below of the work completed on the Penjor to date.  I will post updated images of the work at a later stage. 

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Tree spotlight no:7 – Cordyline Palm

cordyline-australis

Cordyline australis, commonly known as the cabbage tree, cabbage-palm is a widely branched monocot tree endemic to New Zealand. The genus name Cordylinem derives from an Ancient Greek word for a club (kordyle), a reference to the enlarged underground stems or rhizomes, while the species name australis is Latin for “southern”. The common name cabbage tree is attributed by some sources to early settlers having used the young leaves as a substitute for cabbage.

It grows up to 20 metres (66 feet) tall with a stout trunk and sword-like leaves, which are clustered at the tips of the branches and can be up to 1 metre (3.3 feet) long. With its tall, straight trunk and dense, rounded heads, C. Australis is a characteristic feature of the New Zealand landscape. Its fruit is a favourite food source for the New Zealand pigeon and other native birds.

native-nz-cabbage-trees-cordyline-australis-timarusouth-canterburysouth

It grows in a broad range of habitats, including forest margins, river banks and open places, and is abundant near swamps. The largest known tree with a single trunk is growing at Pakawau, Golden Bay. It is estimated to be 400 or 500 years old, and stands 17 metres (56 feet) tall with a circumference of 9 metres (30 feet) at the base. Known to Māori as tī kōuka, the tree was used as a source of food, particularly in the South Island, where it was cultivated in areas where other crops would not grow. It provided durable fibre for textiles, anchor ropes, fishing lines, baskets, waterproof rain capes and cloaks, and sandals.

Hardy and fast growing, C. Australis is widely planted in New Zealand gardens, parks and streets, and numerous cultivars are available. The tree can also be found in large numbers in island restoration projects such as Tiritiri Matangi Island, where it was among the first seedling trees to be planted.

It is also grown as an ornamental tree in Northern Hemisphere countries with mild maritime climates, including parts of the upper West Coast of the United States and the warmer parts of the British Isles, where its common names include Torbay palm, and Torquay palm. It does not do well in hot tropical climates like Queensland, Southeast Asia and Florida.

Magnified view of flowers of C. australis. Each flower has a style tipped by a short trifid stigma. There are also anthers with pollen, and nectar around the base of the ovary. In a good flowering season, a large tree may produce 1 million seeds. Before it flowers, it has a slender unbranched stem. The first flowers typically appear at 6 to 10 years old, in spring. After the first flowering, it divides to form a much-branched crown with tufts of leaves at the tips of the branches. Each branch may fork after producing a flowering stem. The pale to dark grey bark is corky, persistent and fissured, and feels spongy to the touch.

The long narrow leaves are sword-shaped, erect, dark to light green, 40 to 100 cm (16 to 39 in) long and 3 to 7 cm (1.2 to 2.8 in) wide at the base, with numerous parallel veins. The leaves grow in crowded clusters at the ends of the branches, and may droop slightly at the tips and bend down from the bases when old. They are thick and have an indistinct midrib. The fine nerves are more or less equal and parallel. The upper and lower leaf surfaces are similar.

Large, peg-like rhizomes, covered with soft, purplish bark, up to 3 metres (9.8 feet) long in old plants, grow vertically down beneath the ground. They serve to anchor the plant and to store fructose in the form of fructan. When young, the rhizomes are mostly fleshy and are made up of thin-walled storage cells. They grow from a layer called the secondary thickening meristem.

Response to fire

Cordyline australis is one of the few New Zealand forest trees that can recover from fire. It can renew its trunk from buds on the protected rhizomes under the ground. This gives the tree an advantage because it can regenerate itself quickly and the fire has eliminated competing plants. Cabbage tree leaves contain oils which make them burn readily. The same oils may also slow down the decay of fallen leaves, so that they build up a dense mat that prevents the seeds of other plants from germinating. When the leaves do break down, they form a fertile soil around the tree. Cabbage tree seed also has a store of oil, which means it remains viable for several years. When a bushfire has cleared the land of vegetation, cabbage tree seeds germinate in great numbers to make the most of the light and space opened up by the flames.

Insect habitation:

Insects, including beetles, moths, wasps and flies, use the bark, leaves and flowers of the tree in various ways. Some feed or hide camouflaged in the skirt of dead leaves, a favorite dry place for weta to hide in winter. Many of the insect companions of C. Australis have followed it into the domesticated surroundings of parks and home gardens. If the leaves are left to decay, the soil underneath cabbage trees becomes a black humus that supports a rich array of amphipods, earthworms and millipedes.

There are nine species of insect only found on C.australis, of which the best known is Epiphryne verriculata, the cabbage tree moth, which is perfectly adapted to hide on a dead leaf. Its caterpillars eat large holes and wedges in the leaves. The moth lays its eggs at the base of the central spike of unopened leaves. The caterpillars eat holes in the surface of the leaves and leave characteristic notches in the leaf margins. They can infest young trees but seldom damage older trees, which lack the skirt of dead leaves where the parent moths like to hide.

The Cordyline Palm and the Māori:

The tree was well known to Māori before its scientific discovery. The generic Māori language term for plants in the Cordylinegenus is tī, and names recorded as specific to C. Australis include tī kōuka, tī kāuka, tī rākau, tī awe, tī pua, and tī whanake. Each tribe had names for the tree depending on its local uses and characteristics. Simpson reports that the names highlight the characteristics of the tree that were important to Māori. These include what the plant looked like—whether it was a large tree (tī rākau, tī pua), the whiteness of its flowers (tī puatea), whether its leaves were broad (tī wharanui), twisted along the edges (tī tahanui), or spiky (tī tarariki). Other names refer to its uses—whether its fruit attracted birds (tī manu), or the leaves were particularly suitable for making ropes (tī whanake) and nets (tī kupenga). The most widely used name, tī kōuka, refers to the use of the leaf hearts as food.

cordyline_berries

The berries of C. Australis are enjoyed by bellbirds, tūī and pigeons. Māori sometimes planted groves of cabbage trees (pā tī) to attract pigeons which could be snared when they came to eat the berries.

Food

The stems and fleshy rhizomes of C.australis are high in natural sugars and were steam-cooked in earth ovens (umu tī, a large type of hāngi) to produce kāuru, a carbohydrate-rich food used to sweeten other foods. The growing tips or leaf hearts were stripped of leaves and eaten raw or cooked as a vegetable, when they were called kōuka—the origin of the Māori name of the tree.

Preparation of a modern hangi for tourists at Mitai Maori Village, Rotorua

The kōata, the growing tip of the plant, was eaten raw as medicine. When cooked, it was called the kōuka. If the spike of unopened leaves and a few outer leaves is gripped firmly at the base and bent, it will snap off. The leaves can be removed, and what remains is like a small artichoke heart that can be steamed, roasted or boiled to make kōuka, a bitter vegetable available at any time of the year. Kōuka is delicious as a relish with fatty foods like eel, mutton birds, or pigeons, or in modern times, pork, mutton and beef. Different trees were selected for their degree of bitterness, which should be strong for medicinal use, but less so when used as a vegetable.

palm as fibre plant for weaving

Fibre

A tough fibre was extracted from the leaves of C.australis, and was valued for its strength and durability especially in seawater. The leaves were used for making anchor ropes and fishing lines, cooking mats, baskets, sandals and leggings for protection when travelling in the South Island high country, home of the prickly spear grasses (Aciphylla) and tūmatakuru or matagouri (Discaria toumatou). Morere swings provided a source of amusement for Māori children. The ropes had to be strong, so they were often made from the leaves or fibre of C.australis, which were much tougher than the fibers of New Zealand flax. The leaves were also used for rain capes, although the mountain cabbage tree C.indivisa, was preferred. The fiber made from cabbage tree leaves is stronger than that made from New Zealand flax.

ti_kouka_sandals,jpg

Medicine

The Māori used various parts of Cordyline australis to treat injuries and illnesses, either boiled up into a drink or pounded into a paste. The kōata, the growing tip of the plant, was eaten raw as a blood tonic or cleanser. Juice from the leaves was used for cuts, cracks and sores. An infusion of the leaves was taken internally for diarrhea and used externally for bathing cuts. The leaves were rubbed until soft and applied either directly or as an ointment to cuts, skin cracks and cracked or sore hands. The young shoot was eaten by nursing mothers and given to children for colic. The liquid from boiled shoots was taken for other stomach pains. The seeds of Cordyline australis are high in linoleic acid, one of the essential fatty acids.

Increased Magnification reveals…

 

The following slideshow highlights the process by which Clodagh choose  an area of interest on the Palm Tree leaf and through increased magnification brought, in this case an individual somata, into sharp focus.

Under each palm leaf there are numerous breathing holes and these are called somata.  They are not unlike the pores on human skin.

Images start at 92 times and end at 1,600 times magnification.

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Another example of this is the seven images Clodagh took of the bark  surface from the Snake Bark Tree.  This time she started at 17 times and ended at 2,720 times magnification.  

Of interest is the pod like structure that Clodagh honed in on.  To date we have been unable to find out what it is but we plan to ask Professor Daniel L. Kelly from the Trinity College Dublin Botany Department to see if he can put a name on this structure/ organism. 

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Trinity College Trees Booklet

Trinity Trees book - front cover- Oregon Maple.jpg

Trinity College Dublin have compiled and printed a booklet entitled Trees of Trinity College Dublin. A third edition was printed in 2011 and it lists many of the trees to be found on campus. This booklet was jointly edited by David W. Jeffrey and Daniel L. Kelly, the later of which we are delighted to say will be consulting with us on some of the botany aspects of this project.

The booklet groups the various trees on campus into three sections. Each section is called a circuit and lists all the trees to be found in a particular area on campus. Circuit A encompasses the Front Square and Library Square. Circuit B includes trees situated in New Square and House 40 gardens. The final Circuit C covers all the trees in College Park.

Trees of Trinity College booklet-List of trees-tcd map-three tree circuts

Trees of Trinity College booklet also gives specific details on a select number of significant trees, three of which will be included in our project. These trees are the Hop Horn Beam, the Oregon Maple and the Cabbage Tree (Cordyline Palm). See below images of two of the listings in the booklet.

Trinity Trees book-Hop horn beam tree information.jpg

Trinity Trees book - Cabbage tree information