Gymnadenia densiflora differentiates from Gymnadenia conopsea by its size that can reach 1 m, its broad leaves and an impressive spike which can bear up to 200 flowers.

Blooming is a little later than Gymnadenia conopsea.

Although this species strongly resembles Gymnadenia conopsea, some recent morphology and molecular biology studies* support that Gymnadenia densiflora should be considered as a distinct species. However some other authors remain considering it as a subspecies Gymnadenia subsp. densiflora (WAHLENBERG) K. RICHT. 1890 or even as a variety Gymnadenia var. densiflora (WAHLENBERG) HARTM. 1820.

*- Marhold K., Jongepierová I., Krahulcová A. & Kučera J. (2005): Morphological and karyological differentiation of Gymnadenia densiflora and G. conopsea in the Czech Republic and Slovakia. – Preslia, Praha, 77: 159–176
- Stark C.,Michalski S.G.,Babik W.,Winterfeld G. & Durka W. (2011) Strong genetic differentiation between Gymnadenia conopsea and G. densiflora despite morphological similarity Plant Syst Evol 293:213–226.