Hierochloe odorata

Hierochloe odorata or Anthoxanthum nitens[1] (commonly known as sweet grass, manna grass, Mary’s grass or vanilla grass, and as holy grass in the UK,[3] bison grass e.g. by Polish vodka producers[4]) is an aromatic herb native to northern Eurasia and North America. It is a sacred grass of the indigenous peoples of Canada and the United States. It is used as a smudge, in herbal medicine and in the production of distilled beverages (e.g., Żubrówka, Wisent). It owes its distinctive sweet scent to the presence of coumarin.

This variety of grass is different from the species commonly known as Buffalo Grass (Stenotaphrum secundatum) in Australia.

Hierochloe odorata is a very hardy perennial, able to grow to the Arctic Circle. Its leaves do not have rigid stems, so only grow to about 20 cm (7.9 in) in height, and then the leaves grow outward horizontally to 100 cm (39 in) long or more, by late summer. The base of the leaf, just below the soil surface, is broad and white, without hairs; the underside of the leaf is shiny and glabrous. In the wild, the bases of the leaves are frequently purple-red colored, and this indicates a phosphorus-deficient soil.[5]

There are several strains of sweetgrass — a regular strain that can be harvested once or twice a year, and a naturally occurring polyploid strain, which is much faster growing and can be harvested three to five times a year.[5]

Two chemicals found in sweetgrass, phytol and coumarin, repel mosquitoes.[6]