Dactylorhiza sect. Angustifoliae (Verm.) Smoljaninova (1976: 56)

Efimov, Petr, 2025, An update of the taxonomic system of Dactylorhiza (Orchidaceae, Orchideae), Phytotaxa 691 (3), pp. 260-270 : 266-267

7. Dactylorhiza sect. Angustifoliae (Verm.) Smoljaninova (1976: 56) .

Type:— Orchis angustifolia Loisel. ex Rchb. , non M.Bieb. nom. inval. Orchis angustifolia is an unequivocal type according to Art. 10.8, despite this species name being listed by Vermeulen in synonymy of D. traunsteineri . Synonymisation of Orchis angustifolia Loisel. ex Rchb. with D. incarnata , accepted in web-based databases such as POWO, is incorrect, as evidenced by the drawing in the protologue and Eccarius (2016).

≡ Dactylorchis [sect. Maculatae ] subsect. Angustifoliae Vermeulen (1947: 66); (Verm.) Soó (1960: 344), comb. inval. (Art. 41.5).

– Dactylorhiza [sect. Dactylorhiza ] subsect. Angustifoliae Vázquez (2009:139), nom.inval. homonym, based on: Dactylorhiza traunsteineri (Saut. ex Rchb.) Soó. This name was not based on Vermeulen’s Dactylorchis subsect. Angustifoliae , but it is a homonym of the name Dactylorhiza sect. Angustifoliae (Verm.) Smoljaninova , irrespective of different taxonomic ranks (Art. 53.3).

= Dactylorchis [sect. Maculatae ] subsect. Sesquipedales Vermeulen (1947: 68) ; (Verm.) Soó (1960: 347), comb. inval. (Art. 41.5). ≡ Dactylorhiza [sect. Dactylorhiza ] subsect. Sesquipedales (Verm.) Averyanov (1983a: 895) . Type: Dactylorchis sesquipedalis (Willd.) Verm. (= Dactylorhiza elata subsp. sesquipedalis (Willd.) Soó ). The choice of D. elata (Poir.) Soó as type ( Averyanov 1990: 44) is incorrect because the name of this subsection is derived from another species epithet, which should be automatically regarded as its type according to Art. 10.8.

= Dactylorchis [sect. Maculatae ] subsect. Subsesquipedales Vermeulen (1947: 67).— Orchis [sect. Androrchis subsect. Latifoliae ] [stat. indef.] Subsesquipedales Pugsley (1935: 576), nom. inval. (description in English). Type: Dactylorchis baltica (Klinge) Verm. , selected here.

= Dactylorchis [sect. Maculatae ] subsect. Majales Vermeulen (1947: 66).— Orchis [sect. Androrchis subsect. Latifoliae ] [stat. indef.] Majales Pugsley (1935: 577), nom. inval. (description in English).— Dactylorhiza sect. Majales (Verm.) Eccarius (2016: 402) , nom. inval. (Art. 41.5, 41.7, 41.8a). Type: Dactylorchis majalis (Rchb.) Verm.

= Dactylorhiza sect. Ruthenae Eccarius (2016: 480) . Type: D. ruthei (M. Schulze ex Ruthe) Soó. A possible candidate for nothosectional name to accommodate hybrids between sections Maculatae and Dactylorhiza , see below.

= Dactylorhiza ser. Centrales Nelson (1979: 593) . Type: D. majalis (Rchb.) Hunt & Summerh.

= Dactylorhiza ser. Meridionales Nelson (1979: 593) . Type: D. elata (Poir.) Soó.

This section includes allotetraploids that combine genomes from species in sections Maculatae and Dactylorhiza , i.e, fuchsii or maculata with incarnata or euxina . All species in this group should have 80 chromosomes. This section is understood as having hybrid origin between species from different sections, and in this sense the taxonomic rank of a section is appropriate for it according to general taxonomic logic ( Knapp et al. 2004) and nomenclature of ICN. At the same time, the taxa in this section do not represent recent hybrids, but rather hybridogenous species derived from reticulate evolutionary processes, and therefore they are not understood as nothotaxa and the ‘×’ sign is not applied. Being a result of reticulate evolution, section Angustifoliae may not be visualized as a monophyletic group on cladograms compiled using single DNA markers, and this resulted in this section being split in the recent taxonomic system of Eccarius (2016). Only Heslop-Harrison (1954) understood this group as a single unit, and his approach is followed here; other classifications subdivided it into four ( Vermeulen 1947), three ( Soó 1960, Senghas 1968, Eccarius 2016) or two ( Averyanov 1990) sections or subsections.

Hybrids between species in sections Maculatae and Dactylorhiza deserve a special taxonomic name at the rank of nothosection to be created, but this is not a subject of this study. If the name D. ruthei is relegated to spontaneous hybrids, then the name sect. Ruthenae may be used as a nothosectional name to accommodate hybrids between sections Maculatae and Dactylorhiza . However, it should be borne in mind that, morphologically and genetically, such hybrids may be hardly distinguishable from allotetraploids in section Angustifoliae . Some may prefer also to establish special nothosections to accommodate the hybrids between sections Dactylorhiza and Angustifoliae , and Angustifoliae and Maculatae , but such hybrids will be even more difficult in determination, representing in fact reciprocal crosses, and describing such would be a kind of taxonomic overreaction.

At least 19 species, some possibly to be split into several species after more study: Dactylorhiza baltica (Klinge) Nevski , D. baumanniana J. Hölz. & Künkele , D. cordigera (Fr.) Soó , D. elata (Poir.) Soó (probably deserves subdivision into several independent allotetraploids of similar habit), D. francis-drucei (Wilmott) Aver. (with subspecies), D. kerryensis (Wilmott) P.F.Hunt & Summerh. (with subspecies), D. lapponica (Laest. ex Hartm.) Soó , D. majalis (Rchb.) P.F.Hunt & Summerh. , D. nieschalkiorum H.Baumann & Künkele , D. kalopissii E.Nelson (with subspecies), D. pindica B.Willing & E.Willing , D. praetermissa (Druce) Soó (with subspecies), D. purpurella (T.Stephenson & T.A.Stephenson) Soó , D. pythagorae Gölz & H.R.Reinhard , D. ruthei (M.Schulze ex Ruthe) Soó , D. sphagnicola (Höppner) Soó , D. sibirica Efimov , D. traunsteineri (Saut. ex Rchb.) Soó (probably deserving subdivision into several independent allotetraploids of similar habit), D. urvilleana (Steud.) H.Baumann & Künkele.