Platanthera dilatata

Platanthera dilatata
At Glacier National Park in Montana
Conservation status
Secure  (NatureServe) [1]
CITES Appendix II (CITES) [2]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Order:	Asparagales
Family:	Orchidaceae
Subfamily:	Orchidoideae
Genus:	Platanthera
Species:	P. dilatata
Binomial name
Platanthera dilatata (Pursh) Lindl. ex L.C.Beck
Synonyms [3]
Habenaria dilatata(Pursh) Hook. Limnorchis dilatata (Pursh) Rydb. Orchis dilatataPursh Piperia dilatata(Pursh) Szlach. & Rutk.

Platanthera dilatata, known as tall white bog orchid, bog candle, or boreal bog orchid is a species of orchid, a flowering plant in the family Orchidaceae, native to North America. ^{[4] [5] [6]} It was first formally described in 1813 by Frederick Traugott Pursh as Orchis dilatata. ^[7]

It is sometimes called fragrant white bog orchid or scentbottle, for the smell of its flowers, described as intensely spicy or clove-like. ^{[4] [8] [9]}

In the Midwest and northeastern United States and Canada, it grows in cold, calcareous fens, cedar and tamarack swamps, meadows, and marshes, typically in sunny spots. ^{[5] [6]}

Description

Bog candle is an erect, perennial flower growing up to 11–130 cm (4.3–51.2 in) tall. The showy, white flowers are clustered on long spikes. The petals are ovate to linear-lance shaped with smooth edges, not divided or fringed like some other Platanthera species. The lateral sepals spread or reflex. ^{[4] [5]}

The leaves are linear to lanceolate or oblanceolate, and reduce in size toward the top of the plant. The leave size ranges from 3–32 cm (1.2–12.6 in) long to 0.3–7 cm (0.12–2.76 in) across. ^[4]

• 
  Scentbottles at Glacier National Park, Montana
• 
  Inflorescence, British Columbia

Taxonomy

Platanthera dilatata was scientifically described by Frederick Traugott Pursh in 1813 and named Orchis dilatata. It was moved to the genus Platanthera in 1833 by Lewis Caleb Beck crediting John Lindley. Together with its genus it is classified in the family Orchidaceae. ^[3]

Three varieties are accepted: ^[4]

Image	Name	Distribution
	Platanthera dilatata var. albiflora	Colorado to Alaska and Kamchatka [10]
	Platanthera dilatata var. dilatata	Colorado to Alaska, Great Lakes and northeastern US and Canada, absent in most of the Great Plains [11]
	Platanthera dilatata var. leucostachys	western US and Canada, from Baja California to Alaska [12]

Platanthera dilatata has 37 synonyms of the species or one of its three varieties. ^{[3] [10] [11] [12]}

Table of Synonyms

Name	Year	Rank	Synonym of:	Notes
Habenaria borealis var. albifloraCham.	1828	variety	var. albiflora	≡ hom.
Habenaria dilatata(Pursh) Hook.	1823	species	P. dilatata	≡ hom.
Habenaria dilatata var. albiflora(Cham.) Correll	1943	variety	var. albiflora	≡ hom.
Habenaria dilatata var. leucostachys(Lindl.) Ames	1910	variety	var. leucostachys	≡ hom.
Habenaria flagellansS.Watson	1880	species	var. leucostachys	= het.
Habenaria graminifolia(Rydb.) J.K.Henry	1915	species	var. leucostachys	= het.
Habenaria leptoceratitisJ.K.Henry	1915	species	var. leucostachys	= het.
Habenaria leucostachys(Lindl.) S.Watson	1880	species	var. leucostachys	≡ hom.
Habenaria leucostachys var. robusta(Rydb.) J.K.Henry	1915	variety	var. leucostachys	= het.
Habenaria leucostachys var. viridaJeps.	1921	variety	var. leucostachys	= het.
Habenaria pedicellataS.Watson	1877	species	var. leucostachys	= het.
Limnorchis dilatata(Pursh) Rydb.	1901	species	P. dilatata	≡ hom.
Limnorchis dilatata subsp. albiflora(Cham.) Á.Löve & W.Simon	1968	subspecies	var. albiflora	≡ hom.
Limnorchis dilatata var. albiflora(Cham.) Efimov	2007	variety	var. albiflora	≡ hom.
Limnorchis dilatata var. leucostachys(Lindl.) Efimov	2008	variety	var. leucostachys	≡ hom.
Limnorchis dilatata var. linearifoliaRydb.	1901	variety	var. dilatata	= het.
Limnorchis foliosaRydb.	1901	species	var. dilatata	= het.
Limnorchis fragransRydb.	1901	species	var. dilatata	= het.
Limnorchis graminifoliaRydb.	1901	species	var. leucostachys	= het.
Limnorchis leptoceratitisRydb.	1901	species	var. dilatata	= het.
Limnorchis leucostachys(Lindl.) Rydb.	1900	species	var. leucostachys	≡ hom.
Limnorchis leucostachys subsp. robusta(Rydb.) Piper & Beattie	1915	subspecies	var. leucostachys	= het.
Limnorchis leucostachys var. robustaRydb.	1901	variety	var. leucostachys	= het.
Orchis agastachysFisch. ex Lindl.	1835	species	var. dilatata	= het.
Orchis dilatataPursh	1813	species	P. dilatata	≡ hom.
Piperia dilatata(Pursh) Szlach. & Rutk.	2000	species	P. dilatata	≡ hom.
Piperia dilatata var. albiflora(Cham.) Szlach. & Rutk.	2000	variety	var. albiflora	≡ hom.
Piperia dilatata var. leucostachys(Lindl.) Szlach. & Rutk.	2000	variety	var. leucostachys	≡ hom.
Platanthera cylindricaBach.Pyl.	1826	species	var. dilatata	= het.
Platanthera dilatata var. angustifoliaHook.	1839	variety	var. dilatata	= het.
Platanthera gramineaLindl.	1835	species	var. albiflora	= het., nom. illeg.
Platanthera hyperborea var. dilatata(Pursh) Rchb.f.	1851	variety	P. dilatata	≡ hom.
Platanthera hyperborea var. gramineaRchb.f.	1851	variety	var. albiflora	= het.
Platanthera hyperborea var. leucostachys(Lindl.) Kraenzl.	1901	variety	var. leucostachys	≡ hom.
Platanthera leucostachysLindl.	1835	species	var. leucostachys	≡ hom.
Platanthera lindleyiSteud.	1841	species	var. albiflora	= het.
Tulotis albifloraRaf.	1833	species	var. dilatata	= het.
Notes: ≡ homotypic synonym; = heterotypic synonym

Uses

British Columbian Native Americans used the sweet-smelling flowers in washing themselves. ^[13]

References

1. NatureServe. "Platanthera dilatata". NatureServe Explorer. Arlington, Virginia. Retrieved 27 March 2025.
2. "Platanthera dilatata (Pursh) Lindl. ex L.C.Beck, 1833". Species+ . UN Environment Programme World Conservation Monitoring Centre . Retrieved 27 March 2025.
3. POWO. "Platanthera dilatata (Pursh) Lindl. ex L.C.Beck". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 4 November 2025.
4. Sheviak, Charles J (2002). "Platanthera dilatata". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 26. New York and Oxford: Oxford University Press. Retrieved 20 December 2019– via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
5. "Online Virtual Flora of Wisconsin - Platanthera dilatata". wisflora.herbarium.wisc.edu. Retrieved 20 December 2019.
6. Reznicek, A. A.; Voss, E. G.; Walters, B. S., eds. (February 2011). "Platanthera dilatata". Michigan Flora Online. University of Michigan Herbarium. Retrieved 20 December 2019.
7. "Platanthera dilatata". ipni.org. International Plant Names Index. Retrieved 20 December 2019.
8. Brouillet L, Desmet P, Coursol F, Meades SJ, Favreau M, Anions M, Bélisle P, Gendreau C, Shorthouse D, et al. (2010). "Platanthera dilatata (Pursh) Lindley ex L.C. Beck". Database of Vascular Plants of Canada (VASCAN). Retrieved 20 December 2019.
9. NRCS. "Platanthera dilatata". PLANTS Database. United States Department of Agriculture (USDA). Retrieved 20 December 2019.
10. POWO. "Platanthera dilatata var. albiflora (Cham.) Ledeb". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 4 November 2025.
11. POWO. "Platanthera dilatata var. dilatata". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 4 November 2025.
12. POWO. "Platanthera dilatata var. leucostachys (Lindl.) Hultén". Plants of the World Online . Royal Botanic Gardens, Kew . Retrieved 4 November 2025.
13. Fagan, Damian (2019). Wildflowers of Oregon: A Field Guide to Over 400 Wildflowers, Trees, and Shrubs of the Coast, Cascades, and High Desert. Guilford, CT: FalconGuides. p. 65. ISBN   978-1-4930-3633-2. OCLC   1073035766.