Trillium species S through Z are found on this page.
Trillium sessile is frequently misrepresented in cultivation; most of the plants bought or seen under this name actually correspond to T. cuneatum or one of the western sessiles, although the true plant is of much smaller stature than any of these. It can be a charming plant and very fine forms with excellent leaf mottling and petal color can be found. In particular, I have seen yellow plants, and those with yellow flowers edged with purple, creating a very attractive picotee effect. Photos by John Lonsdale.
Trillium simile is a very attractive large species, often forming small clumps, with erect creamy-white flowers (normally) with a purple ovary. The flower is characteristically more funnel-shaped with the ends of the petals flaring sideways. First two photos by John Lonsdale. The last photo is taken by Nhu Nguyen taken in the Great Smokies National Park.
Trillium stamineum is a medium sized species with relatively small flowers, the fragrance of which can be rather unpleasant. However, the thin dark maroon petals are horizontally inclined and uniquely twisted along their length. Less clump forming than its two relatives, it is found in central and western Alabama, eastern Mississippi and west-central Tennessee. Photo by John Lonsdale.
Trillium sulcatum is a large showy species with dark red-maroon to purple flowers with broad petals that are slightly flatter than those of T. simile. Of course occasional white, pink cream and yellow forms can be found together with beautiful bicolors and picotees. Photos by John Lonsdale.
Trillium tschonoskii is a small species from Japan and the Himalayas. Photo by Mari Kitama taken in Japan. Picture of seeds starting to grow in mid-July in England by David Pilling.
Trillium underwoodii It is virtually impossible to distinguish between non-flowering plants of T. decipiens and T. underwoodii. The major difference is one of stature of flowering plants, and the ratio of leaf length to stem height. In T. underwoodii the stems are 3" to 8" tall and 1 to 1.5 times the leaf length, whereas in T. decipiens the ratio increases to over 3, the leaf size remaining similar. Photos by John Lonsdale, Alani Davis, and Jay Yourch.
Trillium undulatum has a broad range in the eastern parts of the United States and Canada, from Georgia north to Ontario and Quebec, following the Appalachian Mountains. In some states, it is listed as endangered. In the wild it is found in humus rich, acidic soil in a shady area. In cultivation, it does well in open woodlands where the soil remains moist in the summer. It takes 2-3 years for plants to flower from seeds. Transplanting should be done while plants are in flowers. Photos by Nhu Nguyen.
Trillium vaseyi is a spectacular species with huge (up to 3" across) flowers of deep red-maroon nodding below the leaves. White flowered forms are known and it is the last species to flower here. Photo by John Lonsdale. See pictures of hybrids of it with Trillium rugelii under that species.