Introduction: Giant Fractal Dandelion
Around May we saw the seedpods of Salsify blooming in the fields around us. They're beautiful! They're like dandelion clocks, but larger and standing taller. We looked closely and saw lots of branching - the pods are made of seed parachutes, the parachutes are made of fronds, and looking through a microscope, each frond has many tiny hairs which catch the wind. With branching from the hairs, through the fronds and parachutes up to the seedpods, we asked the question "why stop there?" and we proceeded to make a giant seedpod out of many seedpods. The result is a "fractal" - a pattern which repeats itself if you look more closely. We call it the "Fractelion".
This project will involve foraging and gardening, flower fixing and arranging, photography and printing, cardboard construction of geodesic polyhedra, bamboo rigging, working with resin, expanding foam and nuts and bolts, and some microscopy on the side! Are you ready?
Step 1: Gathering the Seedpods
As we saw seedpods standing in the fields, fully mature and open, we tried to cut them and bring them home; but this is not so simple! The slightest puff of wind or a wrong move and the whole structure disperses into the air. We therefore found the plants as they were flowering or before the pods opened, and transplanted them into our garden. We could then harvest them as they opened. We worked with 2 or 3 different species or varieties (probably Tragopogon Porrifolius and Dubius) with flowers from yellow through pink to purple. One species has a white diffuse seed pod whereas another is denser, creamier and slightly easier to work with. I couldn't say which is more beautiful; in any case we combined all the types that we found.
Step 2: Fixing the Seedpods
At the moment the pods were fully open we cut them off at the stem. The green leaves around the base of the pod wither as they dry, so we snipped those off with scissors. We then put a few drops of superglue into the core of each seedpod. They then stay fixed for many months (perhaps longer?) and are robust enough to work with. Some stems started to bend as they dried - we helped them to dry straight using drinking straws.
Step 3: Creating the Core
The seeds grow around the core of the seedpod, spacing themselves out, and in so doing they make a pattern (like an "equiangular spiral"). We captured this pattern in a photo, mosaiced it using GIMP software and printed it onto stiff photo paper. On the other side we printed the pattern for a shape which is suitably reminiscent of the seedpod's own quasi-geometrical form. We chose the "rhombicosidodecahedron" - a form which combines faces of different sizes; this matches the natural variation in our seedpods, which are from 8 to 12 cm in diameter.
Here is the pattern from polyhedra.net. To achieve a well-sized core, this pattern was "poster" printed to A3. We then cut with a craft knife and formed the shape, gluing the internal flaps and supporting with clear tape from the outside. There's probably a nicer way of doing this step - suggestions welcome!
Finally, we filled the shape with expanding polyurethane foam, at the same time embedding a central bolt, which was suspended while the foam set.
Step 4: Arranging the Flower Head
The core has a bolt embedded, and we created a temporary holder that we could screw this into while we arranged the seedpods around it. We poked their stems through holes we had punched in the faces of the core and down into the foam. (The picture shows an earlier prototype as well, made from expanded polystyrene).
We cut leaves from thick green paper and arranged these around the base of the seedpod, sandwiched between two nuts.
Step 5: Creating the Stem
The stem is a freshly cut piece of bamboo. We embedded a nut into the end using epoxy resin. We then used further bamboo to create a broad base which could hold the stem vertically. The bamboo is rigged together with cable ties - bamboo construction is a whole beautiful art form of its own, and one which we have largely yet to learn!
Step 6: The Final Piece
It was our pleasure to display this piece both indoors and outdoors during the summer. Some people who saw it said they were struck with the feeling of being small again. Finally we let it disperse into the wind on a blustery day in September, with the fixed seedpods catching the strong wind much as the individual seed parachutes do!
So what next? Well obviously, the next step will be a fractelion made out of fractelions! 2 metres in diameter, 9 metres tall ...
Runner Up in the