Jim Brandenburg / Temperate forest interior with trillium ground cover, Northwoods, Minnesota

Jaymi Heimbuch / Pacific Trillium (Trillium ovatum) flower, Big Creek Park, Newport, Oregon

Nick Hawkins / Red trillium (Trillium erectum), photographed on white background, New Brunswick, Canada, May.

Nick Hawkins / Painted trillium (Trillium undulatum) photographed on white background, New Brunswick, Canada, May.

Steve Gettle / Large-flowered Trillium (Trillium grandiflorum) flower, North America

Dong Lei / Trillium flower (Trillium tschonoskii) in woodland, Lijiang City, Lijiang Laojunshan National Park, Yunnan Province, China. April.

Dong Lei / Trillium plants (Trillium tschonoskii) with buds on forest floor with snow, Lijiang City, Lijiang Laojunshan National Park, Yunnan Province, China. April.

Dong Lei / Hiker with Trillium (Trillium tschonoskii) in bud with snow, Lijiang Laojunshan National Park, Yunnan Province, China. April.

Dong Lei / Trillium plants (Trillium tschonoskii) in bud on forest floor, Lijiang Laojunshan National Park, Yunnan Province, China. April.

Dong Lei / Trillium (Trillium tschonoskii) in bud on forest floor, Lijiang Laojunshan National Park, Yunnan Province, China. April.

LYNN M. STONE / Painted trillium (Trillium undulatum) flower, Pleasant Valley, Connecticut, USA

LYNN M. STONE / Painted trillium (Trillium undulatum) flower,, Pleasant Valley, Connecticut, USA

LYNN M. STONE / Painted trillium (Trillium undulatum) in mixed-woods forest, Pleasant Valley, Connecticut, USA,May.

LYNN M. STONE / Eastern box turtle (Terrapene carolina carolina) in pine forest, by Painted Trillium flower, Connecticut, USA

Doug Wechsler / Red Trillum (Trillium erectum) Fairmount Park, Wissahickon Creek, Philadelphia, Pennsylvania, USA, May.

Doug Wechsler / Toad Trillium (Trillium sessile) Bowman's Hill Wildflower Preserve, Washington Crossing State Park, Pennsylvania, USA, April.

Steve Gettle / Dwarf Crested Iris (Iris cristata) and trillium on forest floor, Great Smoky Mountains National Park, Tennessee

Loic Poidevin / Purple trillium (Trillium erectum) Jacques Cartier Park, Quebec, Canada, May

Loic Poidevin / Purple trillium (Trillium erectum) Jacques Cartier Park, Quebec, Canada, May

MYN / Piotr Naskrecki / White trillium (Trillium grandiflorum) flower, Concord, Massachusetts, USA, May . meetyourneighbours.net project

MYN / Clay Bolt / Vasey's Trillium (Trillium vaseyi) Greenville, USA, April. meetyourneighbours.net project

MYN / Clay Bolt / Little sweet betsy (Trillium cuneatum) Greenville, South Carolina, USA, March. meetyourneighbours.net project

LYNN M. STONE / Bernese Mountain dog pup in spring wildflowers (Anemone and Prairie Trillium), Elburn, Illinois, USA

LYNN M. STONE / Bernese Mountain dog pup in spring wildflowers (Anemone and Prairie Trillium), Elburn, Illinois, USA

LYNN M. STONE / Two Bernese Mountain dog pups sleeping in patch of woodland wildflowers (Anemone and Prairie Trillium), Elburn, Illinois, USA

LYNN M. STONE / Two Bernese Mountain dog pups sleeping in patch of woodland wildflowers (Anemone and Prairie Trillium), Elburn, Illinois, USA

Doug Wechsler / Red Trillum (Trillium erecta) on forest floor. Fairmount Park, Philadelphia, Pennsylvania, April.

Doug Wechsler / Red Trillum (Trillium erecta) flower. Fairmount Park, Philadelphia, Pennsylvania, April.

Rob Tilley / Western white trillium (Trillium ovatum) in flower, Washington, USA, March

Michael Durham / Pacific Trillium (Trillium ovatum) blooming in early spring, Oregon

Michael Durham / Pacific Trillium (Trillium ovatum) flower cross section showing the long stem, subterranean bulb and roots, Oregon

Jerry Monkman / Painted Trillium {Trillium undulatum} flowers, White Mountain National Forest, New Hampshire, USA

Jerry Monkman / Red Trillium {Trillium erectum} flower, Mt. Passaconoway, New Hampshire, USA

Kevin Schafer / Pacific Trillium (Trillium ovatum) flower, Oregon

Albert Aanensen / Trillium flower {Trillium sp} USA

Michael Hutchinson / Coast Trillium {Trillium ovatum} flowering on forest floor beneath Coast Giant redwood trees {Sequoia sempervirens} Lady Bird Johnson Grove, California, USA

Jaymi Heimbuch / Pacific Trillium (Trillium ovatum) flower, Big Creek Park, Newport, Oregon

Jaymi Heimbuch / Purple Trillium (Trillium erectum) flowering, Butano State Park, California

Steve Gettle / Large-flowered Trillium (Trillium grandiflorum), Great Smoky Mountains National Park, Tennessee

Steve Gettle / Large-flowered Trillium (Trillium grandiflorum), Great Smoky Mountains National Park, Tennessee