It’s a sign of spring as welcome as the melting snow. This magnolia tree has occupied a corner of the science building courtyard for nearly a quarter century with the promise of a hint of spring. The Star Magnolia (Magnolia stellata) was planted in 1987 by Wendy Dawson Wagner, the campus horticulturalist, according to Chris Baird, university arborist. While the tree likes the acidic soil of the Avalon Peninsula, Mr. Baird admits it’s a little out of its range here. However, the corner of the Science Building and the courtyard walls – that and the southern exposure – allows it to thrive, despite the occasional dump of snow.