In North America, this segregate of the aviculare complex is known mostly from cool temperate to boreal regions (PL). It has been reported from Ky. (FNA 5). but colls. have not yet been sufficiently reviewed to map here. Closely related plants known as P. aviculare ssp. rurivagum (Jord. ex Boreau) Berher may also be expected (FNA 5). P. bellardii is generally intermediate in overall habit and dimensions between typical aviculare and arenastrum, but has distinctive linear-tending leaves (l/w ca. 4-10+ versus 2-5). P. bellardii differs from arenastrum in its tepals: with unbranched veins (versus branched), margins white (versus usually pink or red), and overall green to reddish-brown color (versus just green). It differs from typical aviculare in its much narrower leaves (ca. 1-7 mm wide versus 6-15 mm); also, its cymes are smaller (usually with 1-3 flowers versus 3-8) and uniformly distributed (versus aggregated at tips); seeds are relatively short (1.2-1.8 mm) and distinctively exerted.