Planet Pic: Pope Francis leads first Palm Sunday Mass

Invoking his grandmother's wisdom, Pope Francis got spontaneous in celebrating his first Palm Sunday Mass in St. Peter's Square this morning.

Francis addressed a crowd of more than 250,000 faithful with simple language, urging them to shun greed and corruption and reach out to "the humble, the poor, the forgotten."

Breaking away from his prepared text, he said: "You can't take it with you, my grandmother used to say."

At the end of the two-hour Mass, Francis took off his red vestments and climbed into an open-topped popemobile to circle through the jubilant crowd wearing his plain white cassock.

He leaned out to shake hands, kissed and patted the heads of infants passed to him by bodyguards and, at one point, blessed a man in a wheelchair.

Here are some images from this morning's service: