. What are the Kinds of ovules ? Explain all kind of Ovules
Here micropyle, chalaza and funicle lie in one straight line. This is primitive and simplest. Polygoniaceae family. e.g. Polygonum.
Here body of the ovule is completely inverted so that micropyle and hilum come to lie very close to each other. Degree of curvature is 1800. Found in Asteraceae family and usually in Gamopetale members e.g. castor.
Embryosac becomes horse shoe shaped.
The micropyle is directed downwards and does not lie on straight line with chalaza. Degree of curvature is 1600. e.g. Poppy (family Alismaceae) and Butamaceae.
Chalaza is present at right angle to funicle.
Ovule is curved. Degree of curvature is between 900 and 1600 (> 900 & < 1600).
Micropyle is directed towards funicle. e.g. Fabaceae, Chinopodiaceae, Brassicaceae.
v)Hemitropus or Hemianatropous
Nucellus and integuments are present at right angle to funicle. Degree of curvature is 900. e.g. Ranunculus and Primula.
Funicle completely surrounds the body of ovule. Rarely found. Degree of curvature is 3600. e.g. Opuntia (Cactaceae), Plumbago (Plumbaginaceae).