Sisyrinchium.—Pretty dwarf iridaceous plants, thriving in peaty soil. S. grandiflorum, 10 in., deep purple or white, blooms about April, and is a fine plant for pot-culture in cold frames.
Sparaxis.—Graceful bulbous plants from South Africa. S. grandiflora, with deep violet-purple, and S. tricolor, with rich orange-red, flowers are best known. S. pulcherrima, a lovely species, 3 to 6 ft. high, with drooping blood-red blossoms, is now referred to the genus Dierama. A warm, light, but rich soil in sheltered spots required.
Spiraea.—Vigorous growing plants of great beauty, preferring good, deep, rather moist soil; the flowers small but very abundant, in large corymbose or spicate panicles. S. Aruncus, 4 ft., white; S. astilbioides, 2 ft., white; S. Filipendula, 1½ ft., and S. Ulmaria, 3 ft., both white; S. palmata, 2 ft., rosy-crimson; and S. venusta, 3 ft., carmine rose, are some of the best.
Statice.—Pretty plants with broad, radical leaves, and a much-branched inflorescence of numerous small flowers. S. latifolia, 2 ft., greyish-blue; S. tatarica, 1 ft., lavender-pink; S. speciosa, 1½ ft., rose colour; and S. eximia, 1½ ft., rosy-lilac—are good border plants. S. bellidifolia, 9 in., lavender; S. emarginata, 6 in., purple; S. globulariaefolia, 9 in., white; and S. nana, 4 in.—are good sorts for the rockery.
Stenactis.—S. speciosa, 1 to 2 ft., is a showy composite, of easy culture in good garden soil; it produces large corymbs of flower-heads, with numerous narrow blue ray-florets surrounding the yellow disk. Now more generally known as Erigeron.
Stipa.—S. pennata (Feather Grass), 1½ ft., is a very graceful-habited grass, with stiff slender erect leaves, and long feathery awns to the seeds.
Stokesia.—S. cyanea, 2 ft., is a grand, autumn-flowering, composite plant, with blue flower-heads, 4 in. across. Sandy loam and warm situation.
Symphytum.—Rather coarse-growing but showy boraginaceous plants, succeeding in ordinary soil. S. caucasicum, 2 ft., with blue flowers changing to red, is one of the finer kinds for early summer blooming.
Thalictrum.—Free-growing but rather weedy ranunculaceous plants, in many cases having elegantly cut foliage. T. aquilegifolium, 2 ft., purplish from the conspicuous stamens, the leaves glaucous, is a good border plant; and T. minus has foliage somewhat resembling that of the Maidenhair fern. Ordinary garden soil.
Tiarella.—T. cordifolia, the foam flower, is very ornamental in border or rockery. Leaves heart-shaped lobed and toothed; flowers white starry; ordinary garden soil.