Biology · Morphology of Flowering Plants · NEET
Diadelphous is found in Pea (Pisum sativum), not China rose. In pea the 10 stamens form two bundles: 9 filaments unite into one bundle and 1 stamen stays free, written as (9)+1. China rose has all stamens joined into a single tube, so China rose is monadelphous. This is a very common NEET trap, so fix it firmly.
They describe two different things. Monadelphous, diadelphous and polyadelphous describe cohesion — how stamens join to EACH OTHER by their filaments (one, two, or many bundles). Epipetalous describes adhesion — the stamen joins to a DIFFERENT whorl, the petal (as in brinjal, potato of Solanaceae). So one term is stamen-to-stamen union, the other is stamen-attached-to-petal.
The (9)+1 pattern is seen in the pea flower (Fabaceae). Out of 10 stamens, 9 join by their filaments into one bundle and the 10th stamen remains free and separate. Because it makes two groups (one bundle of 9 + one free stamen), it counts as two bundles, which is why pea is called diadelphous.
Polyadelphous is related to the androecium — the whorl of stamens (the male reproductive part). The word 'adelphous' always refers to how stamens join by their filaments. It has nothing to do with the gynoecium, corolla or calyx. Polyadelphous means the stamens are united into more than two bundles, as in Citrus (lemon, orange).
Both describe stamens fused to another whorl (adhesion), but the whorl differs. Epipetalous means stamens are attached to the petals (Solanaceae, e.g. potato, brinjal). Epiphyllous means stamens are attached to the perianth / tepals, seen in Liliaceae (Lily). So look at what the stamen sits on: petal = epipetalous, perianth = epiphyllous.
Citrus (lemon, orange) has polyadelphous stamens, where the stamens are grouped into more than two bundles. Remember the NCERT trio together: China rose = monadelphous (1 bundle), Pea = diadelphous (2 bundles), Citrus = polyadelphous (many bundles).
The term 'polyadelphous' is related to
Diadelphous stamens are found in:
Match List I (Types of Stamens) A. Monadelphous, B. Diadelphous, C. Polyadelphous, D. Epiphyllous with List II (Example) I. Citrus, II. Pea, III. Lily, IV. China-rose.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
China rose is monadelphous. All its stamens unite by their filaments into a single tube (one bundle). Polyadelphous (many bundles) is Citrus.
Because the 10 stamens form two groups, not ten separate ones: 9 filaments join into one bundle and 1 stamen stays free. Two bundles = di = diadelphous, written (9)+1.
It involves the filament. Adelphous (mono/di/poly) is fusion of stamens by their filaments. When anthers fuse instead (as in sunflower), that is called syngenesious, which is a different term.
Cohesion is union of stamens with each other (monadelphous, diadelphous, polyadelphous). Adhesion is union of stamens with a different whorl (epipetalous with petals, epiphyllous with perianth).
No. Epipetalous is adhesion (stamen fused to petal), while adelphous terms describe cohesion (stamen fused to stamen). NEET often mixes these two, so keep them separate.
