Variation in length of filaments in stamens is observed in which genus?

• A. Mustard
• B. Dianthus
• C. Salvia
• D. Datura

Answer: (C)

Filament length variation among stamens is a structural setup that aids pollen placement during pollination. In Salvia, the stamens are didynamous, meaning there are two pairs of filaments of different lengths. This arrangement positions the anthers at two heights and works with the flower’s lever mechanism so that when a pollinator depresses or brushes the flower, pollen is efficiently transferred onto its body and then onto the next flower. This functional two-length setup is a distinctive feature seen in Salvia, making it a classic example of this kind of stamen arrangement.

For contrast, other groups show different patterns. Brassicaceae flowers, for instance, have a tetradynamous arrangement with four long and two short filaments across many genera, which is a broader family trait rather than a genus-specific hallmark. Dianthus and Datura don’t emphasize this two-length stamen pattern in the same way, so Salvia best fits the description of variation in filament lengths within stamens at the genus level.