AA Muscat Visiting School

PHYSALIS PERUVIANA PATTERNS

Student Name: Nushrat Jahan

The Physalis Peruviana roots from the family of Solanaceae. It is indenegious to the Andes region in South America, and is now grown in many other countries around the world. The fruit is commonly known as ‘cape gooseberry’.

The plant is herbaceous and is soft wooded. It requires plenty of sunlight and rain throught its growing period and only a little when the food is ripening. The flower is bell shaped and has 5 petals. Once the petal has matured, it is shed and the sepal continues to grow into a bell shape. The fruit develops completely inside the sepal. The sepal protects the growing fruit from predators and from external temperatures. (left-to-right) a. Flower of Physalis Peruviana b. Full grown sepal c. Sepal still attached to the plant d. The paper-like sepal is still intact e. The sepal encloses the fruit within.

The sepals of the plant plays an important factor in its development.

In relation to the petals, there are five sepals. Initially the sepal is green in colour and allows slight photosynthesis. It is upright and chloroplasts are present on the abaxial side. The ridges on the sepals allows for translocation of nutrients from the parent plant to the fruit. The cape gooseberry has a smooth and firm texture. This is made possible due to the sepal, which presents loss of exchange of moisture to the surroundings. Many experiments have been conducted to prove this. This further highlights the strict joint of the sepal, which acts like a protective capsule for the fruit.

The sepal is a thin material, almost paperlike. The veins along its surface allows for the material to expand into the bell shape. There is a heirarchy in the veins of the sepal. Each sepal are identical and have a single primary vein attached to its margin. The petiole, or the stem is attached from the margin. The venal arrangement follows a semicraspedodromous arrangement, which means that the secondary veins branch near the leaf margin, one branch ends at the margin, usually in a tooth, and the other loops to join an adjacent secondary. It is elliptical in shape.

Sepal

Petal

The complex arrangement of veins allow the sepals to enlarge (when the fruit is growing) and shrink (when the fruit has achieved its full maturity). The flow of nutrients through them provide the necessary pressure required for sepals to enlarge. When this enchange is reduced, the sepals tend to shrivel.

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In conclusion, the veins is the control mechanism. It controls the surface area of the sepal while providing structural stability to it.

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(left-to-right) a. Cape gooseberry b. Petal c. Arrangement of petal and sepal d. Fully grown sepal e. Sepal in its last stage

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movement of sucrose

Primary vein Secondary vein

The Calyx

Tertiary vein

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MUSCAT VISITINGThe SCHOOL Calyx

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a. Arrangement of veins (top view) b. Arrangement of veins (side view) c. Veins pattern (top & bottom view) d. Sepals split open at the centre e. Shrivelled sepals f. Change in surface area of the vein g. Hierarchy of veins

PHYSALIS PERUVIANA PATTERNS

Student Name: Nushrat Jahan

My chosen pattern was the venation pattern on the sepals of the Physalis Peruviana. I wanted to investigate on the “structural stability using folds in materials�.

I chose to work with fabric. My experiments would concentrate on the ability to achieve structural stability in elastic fabric though its folds.

My first protoype included a 64cm x 22cm piece of fabric that had steel wires sewed at intervals of 16cm. The steel wires allowed me to stretch the single piece of fabric in different directions (a).

For the next variations, I casted in gypsum. The resulting mould would easily allow me to observe the lines of force and the vertical depth would indicate the weight that it could carry.

For each variation, I used elastic fabric of dimention 30x30 cms.

Steel wires were seamed and inserted onto the surface of the fabric.

The fabric was then pinned to a wooden board which had a hole drilled in to pour the gypsum mixture. Gypsum and water was added keeping a 1:1 ratio in mind.

The first sets of variation had different number of steel wires across the fabric. You could observe the number of variation from the curves on the resulting mould (e-i). As a result of the steel wire, there was an uneven finish to the material (d).

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For the next set of variation, I worked in collaboration with a collegue.

We replaced the wires with a simple seam. the resulting mould were smoother, but it was not possible to control the curves with the seam alone (i-k).

To gain more control of the variations, for the next step we inserted strings along the seams. We could now control the sag/ depth of the curve by keeping the string tight or loose, as we desired (l).

Images m and n demonstrate the method used to create the casting.

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MUSCAT VISITING SCHOOL

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PHYSALIS PERUVIANA PATTERNS

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MUSCAT VISITING SCHOOL

Student Name: Maysa Musallam I Nushrat Jahan