Bees can tell.
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| An older flower, and a honey bee with full bags of pollen. |
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| And a young flower. |
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| And this gumweed flower is half-way between the two above. |
Gumweeds are composites; their flower heads contain many smaller flowers, the petal-like ray flowers around the edge, and a mass of disc flowers in the centre. The individual flowers mature first at the outer edge, then progressively inward, with the youngest flowers in the middle.
Look again at the flowers above; the younger flowers are still closed, the recently mature ones, where the bees are busy harvesting, have protruding anthers loaded with pollen, and on the outer edge, the tiny flowers are busy making seeds. Each single flower will produce one seed.
The ray flowers are sterile.
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| Still here. Moving on tomorrow. |