Page 87 - Biology - XII

6. Cut T.S. of ovary, mount it on a slide and observe
(a) Number of locules in the ovary
(b) Type of placentation

(c) Number of ovules per locule
7. Draw labelled fi gures of your preparation and observations.

Comments
Description of reproductive parts of fl owers
ANDROECIUM
The number of stamens may vary from a few to many in diff erent fl owers. Stamens may be free or united.
If united, they can be of the following type.

1. Syngenesious: Filaments are free and anthers are united, e.g. Sunfl ower. [Fig. 16.1(a)]
2. Synandrous: Stamens fused all through their length, e.g. Cucurbita [Fig. 16.1(b)]
3. Adelphous: Anthers remain free and fi laments are united. Adelphous condition can be
(a) Monoadelphous—United to form one bundle, e.g. China rose [Fig. 16.1(c)]

(b) Diadelphous—United to form two bundles, e.g. Pea [Fig. 16.1(d)]
(c) Polyadelphous—United into more than two bundles, e.g., Lemon [Fig. 16.1(e)]

(a) (b) (c) (d) (e)

Fig. 16.1: (a) Syngenesious (b) Synandrous (c) Monoadelphous (d) Diadelphous and (e) Polyadelphous

Fusion of stamens with other parts of the fl ower gives diff erent structures.
1. Epipetalous: Stamens fused with petals, e.g. Sunfl ower, Datura [Fig. 16.2(a)]
2. Epiphyllous: Stamens fused with perianth, e.g. Lily [Fig. 16.2(b)]

(a) (b)

Fig. 16.2: (a) Epipetalous and (b) Epiphyllous

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