Every accepted species in the genus is listed. A name links to its page when we hold at least three commercially licensed photographs of it. Where we do not, the row shows how many we actually found, which is usually none.
| Species | Authority | Usable photographs | Page |
|---|---|---|---|
| Trillium erectum | L. | 3,709 | documented |
| Trillium grandiflorum | (Michx.) Salisb. | 3,141 | documented |
| Trillium ovatum | Pursh | 2,404 | documented |
| Trillium undulatum | Willd. | 2,387 | documented |
| Trillium recurvatum | L.C.Beck | 831 | documented |
| Trillium cernuum | L. | 748 | documented |
| Trillium cuneatum | Raf. | 699 | documented |
| Trillium sessile | L. | 592 | documented |
| Trillium chloropetalum | (Torr.) Howell | 498 | documented |
| Trillium catesbaei | Elliott | 407 | documented |
| Trillium flexipes | Raf. | 368 | documented |
| Trillium albidum | J.D.Freeman | 255 | documented |
| Trillium nivale | Riddell | 188 | documented |
| Trillium luteum | (Muhl.) Harb. | 171 | documented |
| Trillium foetidissimum | J.D.Freeman | 117 | documented |
| Trillium rugelii | Rendle | 116 | documented |
| Trillium vaseyi | Harb. | 110 | documented |
| Trillium maculatum | Raf. | 84 | documented |
| Trillium reliquum | J.D.Freeman | 79 | documented |
| Trillium angustipetalum | (Torr.) J.D.Freeman | 72 | documented |
| Trillium underwoodii | Small | 57 | documented |
| Trillium decumbens | Harb. | 52 | documented |
| Trillium sulcatum | T.S.Patrick | 44 | documented |
| Trillium discolor | Hook. | 41 | documented |
| Trillium stamineum | Harb. | 41 | documented |
| Trillium viridescens | Nutt. | 37 | documented |
| Trillium simile | Gleason | 33 | documented |
| Trillium gracile | J.D.Freeman | 30 | documented |
| Trillium lancifolium | Raf. | 29 | documented |
| Trillium ludovicianum | Harb. | 18 | documented |
| Trillium petiolatum | Pursh | 17 | documented |
| Trillium tschonoskii | Maxim. | 17 | documented |
| Trillium apetalon | Makino | 15 | documented |
| Trillium decipiens | J.D.Freeman | 15 | documented |
| Trillium kurabayashii | J.D.Freeman | 15 | documented |
| Trillium pusillum | Michx. | 15 | documented |
| Trillium crassifolium | Piper | 13 | documented |
| Trillium oostingii | Gaddy | 12 | documented |
| Trillium texanum | Buckley | 11 | documented |
| Trillium viride | L.C.Beck | 10 | documented |
| Trillium camschatcense | Ker Gawl. | 9 | documented |
| Trillium persistens | W.H.Duncan | 7 | documented |
| Trillium hibbersonii | (T.M.C.Taylor & Szczaw.) D.O'Neill & S.B.Farmer | 1 | below the evidence gate |
| Trillium × crockerianum | Halda | 0 | below the evidence gate |
| Trillium × komarovii | H.Nakai & Koji Ito | 0 | below the evidence gate |
| Trillium × miyabeanum | Tatew. ex J.Samej. | 0 | below the evidence gate |
| Trillium × yezoense | Tatew. ex J.Samej. | 0 | below the evidence gate |
| Trillium channellii | Fukuda, J.D.Freeman & Itou | 0 | below the evidence gate |
| Trillium delicatum | Floden & E.E.Schill. | 0 | below the evidence gate |
| Trillium georgianum | S.B.Farmer | 0 | below the evidence gate |
| Trillium govanianum | Wall. ex D.Don | 0 | below the evidence gate |
| Trillium hagae | Miyabe & Tatew. | 0 | below the evidence gate |
| Trillium scouleri | Rydb. ex Gleason | 0 | below the evidence gate |
| Trillium smallii | Maxim. | 0 | below the evidence gate |
| Trillium taiwanense | S.S.Ying | 0 | below the evidence gate |
| Trillium tennesseense | E.E.Schill. & Floden | 0 | below the evidence gate |
This site is commercial, so it can only publish photographs licensed for commercial use. Roughly three quarters of the photographs on iNaturalist are CC BY-NC, which excludes them. A species needs at least three usable photographs before we will build it a page, because a page with one picture and no traits tells you nothing you could not get from a search result, and generating hundreds of thousands of those is precisely the practice that got the previous version of this site deleted.
So the species above without a link are not errors and they are not omissions. They are real, accepted plants that we cannot yet document to the standard we hold ourselves to, and the count in the photographs column is exactly how far short we fall.