Acacia visco

Acacia visco, now placed by botanists in the genus Parasenegalia, is a graceful, fast-growing tree from the high country of northern Argentina, Bolivia, Chile, and Peru, where it is known simply as visco or viscote. The name nods to the sticky, resinous sap the tree exudes. Unusually among its thorny relatives it is thornless, with a light, open crown of ferny, twice-divided leaves that cast a dappled, forgiving shade.

In late spring the canopy fills with small, fragrant, soft-yellow flowers, a haze of bloom alive with bees, followed by flat seed pods. In its native range it is valued for timber, for fodder, and for the way it holds dry mountain soil; like other legumes it fixes nitrogen and improves the ground beneath it. It grows quickly, reaching the stature of a shade or canopy tree in relatively few years.

For the southern or warm-climate garden it makes a fine, fast specimen or light shade tree where the soil drains freely and the sun is full. Its airy foliage and thornless habit make it safe and pleasant to sit beneath, and its drought tolerance suits it to hot, sunny situations where heavier trees struggle.