[5 Mark each]

Question

Define ptyxis & explain its types.

Vidyadip · Accepted Answer

Rolling or folding of individual leaves is called ptyxis. There are seven types of ptyxis as follows:

Reclinate – When the upper half of the leaf blade is bent upon the lower half as in loquat (Eriobotrya japonica).
Conduplicate – When the leaf is folded lengthwise along the mid – rib, as in guava, sweet potato and camel’s foot tree (Bauhinia).
Plicate or Plaited – When the leaf is repeatedly folded longitudinally along ribs in a zig – zag manner, as in Borassus flabellifer.
Circinate – When the leaf is rolled from the apex towards the base like the tail of a dog, as in ferns.
Convolute – When the leaf is rolled from one margin to the other, as in banana, aroids and Indian pennywort. Musa and members of Araceae.
Involute – When the two margins are rolled on the upper surface of the leaf towards the mid – rib or the centre of the leaf, as in water lily, lotus, Sandwich Island Climber (Antigonon) and Plumbago.
Crumpled – When the leaf is irregularly folded as in cabbage.

Answer