Dulcet aroma in the air? It's the blooming of Osmanthus Fragrans, aka sweet olive

What's that marvelous if mysterious fragrance on the street today?

It is Sweet Osmanthus (Osmanthus fragrans; also known as Sweet Olive or Tea Olive). It's an evergreen shrub or small tree growing to 5-12 m tall, says wikipedia.org. It is native to Asia, from the Himalaya east through China to Japan.

Its flowers are small (1 cm long), white, with a four-lobed corolla and have a strong fragrance.It is cultivated as an ornamental plant in gardens (both in Asia and elsewhere in the world) for its deliciously fragrant flowers which carry the scent of ripe peaches or apricots.

In Chinese cuisine, the flowers are also used to produce osmanthus-scented jam (called guì huā jiàng, 桂花醬 or 桂花酱), sweet cakes (called guì huā gāo, 桂花糕), dumplings, soups, and even liquor (桂花酒).

If it seems to remind you of uptown New Orleans, you're right. St Charles Avenue and City Park are practically forests of Sweet Olive. It's also redolent of Houston's Montrose and of the old neighborhoods in Mobile and Biloxi.