Da tempo volevo approfondire le ricerche su questa questione irrisolta (Listera o Neottia), per cercare di chiarirmi le idee e giungere ad una conclusione, che per ora vedo ancora lontana. Vorrei però iniziare a condividere quanto ho avuto modo di trovare. A febbraio di quest'anno è stato pubblicato un interessante articolo da un gruppo di ricercatori e botanici cinesi, su una prestigiosa rivista.
1. Xiang X-G., 2012Xiao-Guo Xiang, De-Zhu Li, Wei-Tao Jin, Hai-Lang Zhou, Jian-Wu Li & Xiao-Hua Jin.
Phylogenetic placement of the enigmatic orchid genera Thaia and Tangtsinia: Evidence from molecular and morphological characters. Taxon 61 (1) - February 2012: 45-54.
Di seguito vi riporto uno dei paragrafi, riguardanti le relazioni "genetiche" che hanno trovato all'interno della tribù Neottieae.
Cita:
Relationships within the tribe Neottieae.In molecular studies using
rbcL and
matK,
Freudenstein & al. (2004) proposed that tribe Neottieae was sister group to other lower Epidendroideae, but this was poorly supported due to limited sampling. Our analyses indicated that tribe Neottieae is well supported within lower Epidendroideae based on the
rbcL, matK and psaB analyses (Fig. 2). These findings are consistent with the molecular analysis by
Cameron & al. (1999). Tribe Neottieae (largely following
Bateman & al., 2005, but excluding
Thaia) was divided into three clades (Fig. 3). Within clade I, the monophyly of
Cephalanthera (including
Tangtsinia) was well supported, and relationships were identified by the molecular data as discussed above. Clade II contains four genera, i.e.,
Neottia (including
Listera),
Aphyllorchis,
Limodorum, and
Epipactis.
Chase & al. (2003) suggested that Listera and Neottia should be combined which was also followed by others (Bateman & al., 2005;
Chen & al., 2009).
Aphyllorchis and
Limodorum were sister groups (
Roy & al., 2009) with strong support, sharing several morphological characters (Bateman & al., 2005).
Epipactis was sister to these two groups.
Palmorchis was the earliest divergent clade (clade III; Fig. 3).
Partendo da questo articolo, mi sono procurato tutti gli articoli citati, più alcuni altri, per approfondire la questione.
2. Cameron et al., 1999Cameron, K.M., Chase, M.W., Whitten, W.M., Kores, P.J., Jarrell, D.C., Albert, V.T., Yukawa, T., Hills, H.G. & Goldman, D.H. 1999.
A phylogenetic analysis of the Orchidaceae: Evidence from rbcL nucleotide sequences. Amer. J. Bot. 86: 208–224.
Si tratta delle prime analisi genetiche approfondite, volte ad analizzare i rapporti presenti nel clade Epidendroideae.
Cita:
3. Chase et al., 2003Chase M.W., Cameron K.M., Barrett R.L. e Freudenstein J.V. 2003 -
DNA data and Orchidaceae systematics: A new phylogenetic classification. pp.69-89. in: Dixon K.W., Kell S.P., Barrett R.L., e Cribb P.J. (eds.),
Orchid conservation. kota Kinabalu, Sabah: Natural History Publications.
Questi autori sono stati i primi a proporre formalmente, sulla base delle analisi genetiche effettuate, di incorporare il genere Neottia in Listera, ma siccome Neottia fu istituito per primo, ha priorità su Listera.
Cita:
Neottieae as circumscribed here are the same as in Dressler (1993), but with the addition of Palmorchis. Except for Aphyllorchis and palmorchis, this small group of six genera are from the temperate zone of the Northern Hemisphere. Neottia is embedded within Listera, but the former is the older name. [...]
4. Freudenstein et al. 2004Freudenstein, J.V., Van den Berg, C., Goldman, D.H., Kores, P.J., Molvray, M. & Chase, M.W. 2004.
An expanded plastid DNA phylogenetic analysis of Orchidaceae and analysis of jackknife clade support strategy. Amer. J. Bot. 91: 149–157.
Sulla base di analisi effettuate su due regioni geniche
rbcL and matK, arrivano a dimostrare una stretta parentela tra Neottieae ed Epidendroideae, anche se i dati non sono abbastanza certi statisticamente.
Cita:
The highest support value that decreased with increased tree saving was 93% in the 1/1 TBR tree. The greatest decrease observed was 17% fot the Epipactis + Listera + Neottia cade. Not every low or mid-range support value decreased, however. In no case did a clade increase by four or more points in the 1/20 analysis relative to the 1/1 analysis. [...]
Within Epidendroideae, Neottieae + Palmorchis is supported at 87%, and Neottieae, comprising Cephalanthera, Epipactis, Neottia, and Listera, at 100% (73% with rbcL). The remainder of epidendroids are united at 71%.
5. Bateman, Pridgeon et al., 2005Bateman, R.M., Hollingsworth, P.M., Squirrel, J. & Hollingsworth, M. 2005. Tribe Neottieae. Pp. 487–515 in: Pridgeon, A., Cribb, P.J., Chase, M.W. & Rasmussen, F.N.:
Genera Orchidacearum, vol. 4, Epidendroideae, pt. 1. Oxford: Oxford University Press.
In questa opera monumentale, gli autori riprendono le analisi effettuate da Chase e Freudenstein nei due anni precedenti. Nei testi viene riportato quanto segue.
Cita:
Dressler (1981, 1993) indicated that the "typical" member of Epidendroideae has the following characters: epiphytism, pseudobulbs or corms, distichous, articulated (cauducous), conduplicate, fleshy leaves; lateral inflorescens; hard pollinia; and a caducous anther. Although plants with these characters will surely be members of Epidendroideae, the characters are not strictly diagnostic. The presence of sclerenchyma in leaves also appears to be a good character distinguishing the great majority of Epidendroideae from Orchidoideae, but Vanilloideae also have sclerenchyma in their leaves.
Neottia (Listera) and other Neottieae lack sclerenchyma, and Neottia was a member of the orchidoid clade in the morphological results of Freudenstein and Rasmussen (1999). [...]
If we use the circumscription for Epidendroideae observed in the DNA studies, then we end up with no clear set of strict morphological synapomorphies that allows all of them to be placed in the higher taxa where DNA data have placed them. The great majority of orchid taxa can be placed in subfamilies observed in the DNA trees by using morphological characters, but the exceptions are numerous and well known. By emphasizing the above-mentioned leaf and column characters simultaneously, only a few taxa such as
Neottia (Listera) would fail to be accurately placed.
[...]
PDF:
http://fds.oup.com/www.oup.com/pdf/13/9780198507123.pdf 6. Chen et al., 2009Chen, S.C., Gale, S.W. & Cribb, P.J. 2009. Neottia. Pp. 184–195 in: Wu, Z.Y. & Raven, P.H. (ed.),
Flora of China, vol. 25. Beijing: Science Press; St. Louis: Missouri Botanical Garden Press.
Il Progetto Flora of China, è confluito prima in eFloras.org, e poi in
Tropicos.org. Tropicos ® è un progetto internazionale creato originariamente per i ricercatori e il mondo accademico, poi messo a disposizione della comunità scientifica mondiale. Tutti i dati della nomenclatura, bibliografia e campioni d'erbario accumulati nelle banche dati elettroniche del MBG (Missouri Botanical Garden) nel corso degli ultimi 25 anni sono a disposizione del pubblico. Questo sistema ha oltre 1,2 milioni di nomi scientifici e 4 milioni di campioni d'erbario.
Riportano nel loro database, e relativa pubblicazione di cui sopra, il genere Listera in sinonimia del genere Neottia.
Cita:
63. Neottia Guettard, Hist. Acad. Roy. Sci. Mém. Math. Phys. (Paris IV) 1750: 374. 1754.
SIN:
Distomaea Spenner;
Listera R. Brown (1813 nom. cons.), not Adanson (1763);
Neottidium Schlechtendal;
Nidus Rivinus;
Pollinirhiza Dulac. [...] Leaves (when present) 2 [very rarely 3 or 4 in
Neottia ovata (Linnaeus) Bluff & Fingerhuth] opposite or subopposite, usually borne midway along stem, sessile or subsessile, green, ...
Link:
http://www.efloras.org/florataxon.aspx? ... _id=122112 7. Roy et al., 2009Roy, M., Watthana, S., Stier, A., Richard, F., Vessabutr, S. & Selosse, M.A. 2009.
Two mycoheterotrophic orchids from Thailand tropical dipterocarpacean forests associate with a broad diversity of ectomycorrhizal fungi. B. M. C. Biol. 7: 51.
Cita:
Phylogenetic position of Aphyllorchis spp. and C. exiguaBased on three markers (
ITS, trnS-G and rbcL; GB accession numbers FJ454868, FJ454884) the Neottieae tribe was monophyletic and included the two Aphyllorchis under study (Fig. 2).
The genera Epipactis, Listera and Cephalanthera were monophyletic, but this, together with their relative positions, remained weakly supported.
PDF:
http://www.biomedcentral.com/content/pd ... 7-7-51.pdf Altri due lavori piuttosto recenti che ho trovato e che accettano il cambio di genere Listera - Neottia sono i seguenti:
8. Bhakta B. Raskoti, Jeffrey J. Wood, Rita Ale, 2012Neottia chandrae sp. nov. (Orchidaceae) from Nepal, Nordic Journal of Botany, Vol. 30, Issue 2, pages 187–189, April 2012
Cita:
Chase et al. (2003) considered Listera simply photosynthetic members of Neottia and suggested that the two genera should be combined on the basis of DNA studies. This view was followed by Pridgeon et al. (2005). Neottia is the oldest name and therefore has priority. Neottia s.l. comprises approximately 60 species widely distributed in the northern temperate zone of the Old and New World, with a few species extending south to Taiwan and Vietnam (Chen et al., 2009). The photosynthetic members of the genus are distinguishable by the single pair of simple, opposite leaves with secondary reticulate venation which are borne near the middle of the plant and flowers with an apically bifid, callose lip that is commonly much larger that the sepals and petals. Some species (Neottia ss) lack green leaves or chlorophyll and have a root-stock composed of densely clustered fleshy roots resembling a bird's nest.
9 - 10. Tian-Chuan Hsu, Shih-Wen Chung, 2009Nomenclature changes of some orchids in china and Taiwan, Taiwan Jour. for Sc. 24 (1): 75-78
e
Supplement to he rchid Flora of Taiwan, Taiwania, 54 (1):82-87
Cita:
Phylogenetic analysis of the Neottieae resulting from molecular data (Chase et al. 2003) has revealed that Listera is paraphyletic. Since there is no significant difference in floral morphology, the monophyletic Neottia s.l. including Listera and Neottia s.s. is then accepted (Chase et al. 2003, Bateman et al., 2005)
Recent phylogeny analyses (Chase et al., 2003; Pridgeon et al., 2005) reveals that the saprophytic Neottia s.l. was nested within Listera, but the former name was published earlier. Since their floral characters were indistinguishable either, a broad sensed Neottia including Listera should be an appropriate taxonomic concept. Almost all nomenclature works had been done by Szlachetko (1995).
A fronte di questi lavori riporto l'elenco completo dei sinonimi della
Listera ovata e della
Listera cordata e dei due generi, Listera e Neottia, per avere un riferimento cronologico e poter stabilire quali nomi hanno priorità.
Neottia Guett., Hist. Acad. Roy. Sci. Mém. Math. Phys. (Paris, 4to) 1750: 374 (1754), nom. cons.
Listera R.Br. in W.T.Aiton, Hortus Kew. 5: 201 (1813), nom. cons.
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Ophrys ovata Linneo, Sp. Pl.: 946 (1753).
Epipactis ovata (L.) Crantz, Stirp. Austr. Fasc., ed. 2, 2: 473 (1769).
Ophrys bifolia Lamarck, Fl. Franç. 3: 516 (1779).
helleborine ovata (L.) F.W.Schmidt, Fl. Boëm. 1: 80 (1793).
Malaxis ovata (L.) Bernh., Syst. Verz.: 315 (1800).
Epipactis ovalifolia Stokes, Bot. Mat. Med. 4: 302 (1812)
Listera ovata (L.) R.Br. in W.T.Aiton, Hortus Kew. 5: 201 (1813).
Neottia latifolia Richard, De Orchid. Eur.: 37 (1817).
Serapias ovata (L.) Steud., Nomencl. Bot.: 766 (1821).
Distomaea ovata (L.) Spenn., Fl. Friburg. 1: 246 (1825).
Neottia ovata (L.) Bluff & Fingerh., Comp. Fl. German., ed. 2, 2: 435 (1838)
Listera multinervia Peterm., Flora 27: 369 (1844).
Pollinirhiza ovata (L.) Dulac, Fl. Hautes-Pyrénées: 120 (1867).
Diphryllum ovatum (L.) Kuntze, Revis. Gen. Pl. 2: 659 (1891).
Bifolium ovatum (L.) Nieuwl., Amer. Midl. Naturalist 3: 129 (1913).
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Ophrys cordata Linneo, Sp. Pl.: 946 (1753).
Epipactis cordata (L.) All., Fl. Pedem. 2: 152 (1785).
helleborine cordata (L.) F.W.Schmidt, Fl. Boëm. 1: 81 (1793).
Cymbidium cordatum (L.) Londes, Mém. Soc. Imp. Naturalistes Moscou 1: 282 (1811).
Listera cordata (L.) R.Br. in W.T.Aiton, Hortus Kew. 5: 201 (1813).
Neottia cordata (L.) Richard, De Orchid. Eur.: 37 (1817).
Serapias cordata (L.) Steud., Nomencl. Bot.: 766 (1821).
Distomaea cordata (L.) Spenn., Fl. Friburg. 1: 247 (1825).
Pollinirhiza cordata (L.) Dulac, Fl. Hautes-Pyrénées: 120 (1867).
Diphryllum cordatum (L.) Kuntze, Revis. Gen. Pl. 2: 659 (1891).
Bifolium cordatum (L.) Nieuwl., Amer. Midl. Naturalist 3: 129 (1913), nom. illeg.
A fronte di tutto questo, riporto i risultati di ricerca dei principali database botanici, dai quali si può dedurre che non c'è ancora un univoco parere tra i vari compilatori, anche se, nel corso degli ultimi 13 anni sono state eseguite molteplici analisi, effettuate da più gruppi, con più tipi di marker genetici, implementati e migliorati nel corso degli anni [
Cameron, 1999: rbcL ;
Freudenstein, 2004: rbcL e matK ;
Roy, 2009: ITS, trnS-G e rbcL ;
Xiang, 2012 : rbcL, matK e psaB] e sempre con risultati più o meno concordanti.
The Plant List:
Neottia ovataKew Gardens Checklist:
Neottia ovataThe Euro+Med:
Neottia ovataTropicos - Missouri Botanical Garden:
Listera ovata