Question

Ptyxis is
A. Arrangement of leaves on stem
B. Arrangement of leaves in the bud
C. Folding of lamina in bud
D. Both B and C

Answer 1

Hint: The word ptyxis is related to the botany or plants. Leaves are the lateral appendage of the stems of vascular plants. The leaves rise above the ground and perform photosynthesis (a process by which plants make their own food with the help of Sunlight, Chlorophyll, Water, Carbon dioxide). Each leaf have two parts-
a. Petiole – with the help of petiole leaf is joined to the stem.
b. Lamina – It is the broader blade of the leaf.

Complete Answer:
Ptyxis: Ptyxis is a way in which an individual leaf is folded in the bud. Ptyxis can occur in many forms such as-
1. Reclinate – In this the upper half of the leaf bent upon the lower half. This form of Ptyxis can be seen in loquat (Eriobotrya japonica).
2. Conduplicate – In this the leaf is folded lengthwise along the midrib. This form of ptyxis can be seen in Guava, sweet potato and camel’s foot tree.
Pilicate or plaited – In this form the leaf is repeatedly folded longitudinally along the ribs in zig-zag manner. This form of ptyxis can be seen in Borassus flabellifer.
3. Circinate – In this form of ptyxis, the leaf is rolled from the apex towards the base like the tail of a dog. This type of ptyxis can be seen in ferns.
4. Convolute – In this the leaf is rolled from one margin to the other margin. This form of ptyxis can be seen in banana, aroids, Indian pennywort, etc.
5. Involute – In this type the two margins of the leaf are rolled on the upper surface of the leaf towards the midrib or the centre of the leaf. This form of ptyxis can be seen in water lily, lotus, Sandwich island climber, etc.
6. Crumpled – In this form of ptyxis the leaf is folded irregularly. Example – in cabbage.

Additional information:
- Arrangement of leaves on the stem is called phyllotaxy.
- Arrangement of leaves in a bud is called a venation.

Hence, option C is the correct answer for this question.

Note: The study of different kinds of venation, phyllotaxy, ptyxis help the taxonomists to differentiate between a variety of plants and in their classification. The classification of plants into several different – different categories make the study of a wide variety of plants possible and easy.