Fleeting Reds

The Kosam trees (Schleichera oleosa) of Delhi put out a spectacular display last week.

Just two weeks ago these trees reminded me of the onset of Autumn in Japan. Like the Ginkgo's, the Kosam's too turned their otherwise unremarkable foliage into shades of yellow and dropped them off, leaving nothing but a skeleton of barren branches.

Then, unlike the Ginkgo's which remain barren until spring, the Kosam's sprout tender young leaves almost immediately. The leaves turn deep scarlet for a few days before turning into a regular green color.

What could be the evolutionary story behind this fleeting display? Is it meant to attract the Lac insects? Do they help in pollination?