Stem 20-50 cm tall, branched, winged, flexuose. Leaves mostly basal, 4-6 mm wide. Spathes almost equal. Flowers violet-blue with yellow centre, 10-15 mm wide; late spring to summer. Segments blunt with a tiny point in a notch at the tip. Syn. S. angustifolium Miller.; S. bermudianum L.

Eastern N America.

A variant with pure white flowers is also grown.

S. montanum Greene, Blue-eyed Grass from western N America has stems 30-55 cm tall, unbranched, winged, 4 mm wide. Leaves all basal, 2-3 mm wide. Spathes strongly unequal. Flowers deep blue to blue-violet with yellow centre. Segments elliptic, 10-15 mm long, blunt with a tiny point in a notch at the tip. 'Alba' Flowers pure white.

S. idahoense Bicknell is a similar but smaller plant with stems to 3 mm wide.

Source: Cooke, D. (2005). Iridaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.