Sternbergia sicula ( Autumn Daffodil )

Bulbous perennial that bears yellow star-shaped flowers in the fall. Leaves are borne at the same time and are dark green with gray stripes. Ideal for a sunny rock garden; does not like winter moisture.

Sternbergia clusiana ( Autumn Daffodil )

Bulbous perennial that bears yellow funnel-shaped flowers in the fall. Blooms appear before the grayish green foliage emerges. Ideal for a sunny rock garden; does not like winter moisture. Sometimes referred to as Sternbergia macrantha.

Stephanocereus leucostele ( Cactus )

Upright and columnar, spiny, ribbed cactus with blueish green stems. White flowers with scaly yellow tubes are borne in summer from woolly cephaliums. Green fruit follows blooms and take many weeks to ripen.

Stenotus acaulis ( Stenotus )

Subshrub with mat-forming habit and upright, thin, stems. Leaves are lance-shaped, tapered, and dark green. Single, daisy-like, yellow flowers bloom in summer. Ideal in a rock garden. Sometimes referred to as Haplopappus acaulis.

Stenanthium gramineum ( Stenanthium )

Bulbous perennial with linear, basal, bright green foliage. Arching panicles of fragrant, star-shaped, greenish white, white, or purple flowers bloom in summer. Sometimes referred to as S. angustifolium.