Sweetgrass

Sweetgrass is Hierochloe odorata, a grass that smells of new-mown hay because of the coumarin it carries, and the scent strengthens as it dries. It is cut, cleaned and braided in three strands, and the braid is burned at one end so that it smoulders rather than flames.

Its role is specific. In the practice of many Indigenous peoples of North America, sweetgrass is used to call in what is good, and it is typically used after something purifying rather than instead of it. That ordering is not a detail. A commercial smudge kit that packages sage, sweetgrass and a shell together as a single generic technique is describing a practice that belongs to particular peoples, with particular protocols, as though it were a universal method with no owner.

The atlas records the material and records that its ceremonial use is not general property. Where a peoples' practice is restricted, saying so is the accurate description, not a disclaimer bolted onto one.

Ecologically the grass is under pressure in parts of its range from development and from commercial harvesting for the smudge market, and several tribal programmes now manage stands deliberately. Research carried out with Potawatomi harvesters found that stands harvested in the traditional way, taking some and leaving some, did better than stands left entirely alone, which is a finding about management rather than about mysticism.

The smell of sweetgrass is coumarin, the same compound that gives new-mown hay, tonka bean and woodruff their scent. It is not present in the living plant in that form: the grass carries a glycoside that releases coumarin as the tissue dries and the cells break down, which is why a fresh blade smells of very little and a cured braid smells strongly.

That is a general rule for hay-scented plants and it explains a practical feature of the ritual material. Sweetgrass has to be dried properly to work at all, and a badly cured braid is disappointing rather than merely weaker.

Coumarin is also why the plant has a regulatory history. It is restricted as a food additive in several jurisdictions on liver toxicity grounds, which affects the flavouring trade rather than the ceremonial one. Zubrowka, the Polish bison grass vodka, is flavoured with a close relative of sweetgrass and is sold in the United States only in a version with the coumarin removed.

Hierochloe means holy grass, which is a translation of the older European name. The plant's northern European populations were strewn before church doors on saints' days in parts of Scandinavia and the Baltic, which is a use entirely independent of the North American one and is much less well known.