Diversity of flowers
A flower with both stamens and pistil is bisexual (apricot, cherry, apple, peach). A flower with only stamens is a staminate flower, with only a pistil a pistillate flower — both are unisexual. If staminate and pistillate flowers grow separately on the same plant, the plant is monoecious (maize, pumpkin); if staminate flowers are on one plant and pistillate flowers on another, it is dioecious (nettle, poplar, willow). If a flower can be divided into more than two equal parts by lines through its centre it is regular (apple, quince, peach, cotton, dog rose, tulip); if only one line divides it into two equal halves, or none does, it is irregular (violet, bean, alfalfa, salvia, basil). A dioecious species needs both plants nearby to produce seed. In some trees (willow, poplar, walnut) the perianth has disappeared or turned into scales.
| Sex | Bisexual: stamens and pistil | Unisexual: only stamens or only pistil |
|---|---|---|
| On the plant | Monoecious: both kinds on one plant | Dioecious: on separate plants |
| Symmetry | Regular: several lines of symmetry | Irregular: one line or none |
“Flower analysis”: analyse 6 flowers in the table (apple, pumpkin, willow, bean, tulip, violet): bisexual or unisexual? regular or irregular? Is the plant monoecious or dioecious? If possible, examine real flowers with a magnifier. Safety: allergic pupils take care; do not taste flowers of poisonous plants.