I posted about the Phyllanthus cuscutiflorus recently. From the Euphorbiaceae Family, this other Phyllanthus pulcher (synonym: Diasperus pulcher, Epistylium pulchrum, Phyllanthus asteranthos; common name: Tropical Leaf-Flower) plant has numerous similar small flowers overhanging from the underside of the leaves.
The red flowers also have white-frilled petals that provide stark contrast against the green leaves. A link is shown below: