Editing Trillium erectum (section)

===Infraspecies===
[[File:Trillium erectum comparing red and white color varieties.jpg|thumb|Composite image showing both red and white color morphs of the flower of ''Trillium erectum''. Note that both morphs have a dark purple [[gynoecium]] with contrasting anthers]]

{{As of|October 2021}}, [[Plants of the World Online]] (POWO) accepts two [[infraspecific name]]s:{{r|POWO:304585-2}}

* ''Trillium erectum'' var.&nbsp;''album'' {{small|(Michx.) Pursh}}
* ''Trillium erectum'' var.&nbsp;''erectum''

POWO lists 30&nbsp;[[Synonym (taxonomy)|synonym]]s for variety ''erectum'' and 3&nbsp;synonyms for variety ''album''.{{r|POWO:77172323-1|POWO:258309-2}} Michaux introduced the term ''album'' in 1803 by describing ''Trillium rhomboideum'' var.&nbsp;''album'',{{r|IPNI:258370-2}} a variety with a smaller flower and white petals.{{r|Michaux 1803}} Pursh gave a similar description for ''Trillium erectum'' var.&nbsp;''album'' in 1814.{{r|IPNI:258309-2|Pursh 1814}} The word ''album'' means "bright, dead-white",{{sfnp|Gledhill|2008|p=41}} a reference to the variety's white petals, a distinctive feature noted by both Michaux and Pursh. 

[[John Kunkel Small]] raised ''T.&nbsp;rhomboideum'' var.&nbsp;''album'' {{small|Michx.}} to species rank in 1903.{{r|IPNI:258288-2}} In his description, he added long anthers to the list of characters cited by Michaux while expanding the range of the taxon to include [[North Carolina]], [[Tennessee]], and Georgia.{{r|Small 1913}} In 1917, R.R.&nbsp;Gates recognized the existence of two distinct forms of ''T.&nbsp;erectum'' with white petals, one of which was represented by the previously mentioned ''Trillium album'' {{small|(Michx.) Small}}.{{r|Gates 1917}} This prompted [[Ralph Hoffmann]] to propose ''Trillium erectum'' f.&nbsp;''albiflorum'',{{r|IPNI:258308-2|Hoffmann 1922}} a white-flowered form of ''T.&nbsp;erectum'' that occurs occasionally and spontaneously throughout the range of the species. Thus the distinct taxa recognized by Gates were fully realized by 1922.

POWO cites the Flora of North America (FNA) as an authority for ''Trillium erectum'' var.&nbsp;''album'' {{small|(Michx.) Pursh}}.{{r|POWO:258309-2}} The treatment of the variety in FNA expands the original concept described by Michaux to include the occasional white-flowered red trillium found throughout the range of the species.{{r|FNA:242102310}} Under this scheme, all non-white petal colors (including yellow) comprise the typical variety (var.&nbsp;''erectum'').{{r|FNA:242102311}} Thus FNA lumps the two forms recognized by Gates into a single taxon. In contrast, POWO restricts the range of ''Trillium erectum'' var.&nbsp;''album'' to eastern Tennessee and western North Carolina. Noting that its distribution is poorly understood, Flora of the Southeastern United States (FSUS) describes a white-flowered variety of ''T.&nbsp;erectum'' common to the foothills of the [[Great Smoky Mountains]], in North Carolina and Tennessee, but rare elsewhere.{{r|FSUS 2022}} FSUS suggests that variety ''album'' may be genetically distinct from variety ''erectum'',{{sfnp|Weakley|Southeastern Flora Team|2022|p=215}} while other evidence suggests there is little genetic difference between the two varieties.{{r|Brenek 2021}}