Commelina guyanensis Klotzsch ex Seubert (1855: 262)

Hassemer, Gustavo, 2017, Taxonomic and nomenclatural notes on neotropical Commelina (Commelinaceae), and an identification key for Brazil, Guyana, Paraguay, Suriname and Uruguay, Phytotaxa 303 (2), pp. 101-117 : 102

2. Commelina guyanensis Klotzsch ex Seubert (1855: 262) , nomem dubium

– Commelina guianensis Klotzsch ex Schomburgk (1849: 1064) , nom. inval. (Art. 38.1; see also Art. 38.3)

Notes: —This name was first published in Schomburgk (1849: 1064) as “ C. guianensis Kl. ”, but this is an invalid name since no diagnosis or description was provided (Art. 38.1; see also Art. 38.3). Later, Seubert (1855) validly published this name with a slightly different spelling; “ Commelina guyanensis ”. The type of this name, which was collected by R.H. Schomburgk in Guyana, was most probably destroyed in 1943 when B was bombed. No extant specimens that could be considered as original material for this name could be located at B (Robert Vogt, pers. comm.), nor at any other herbaria consulted, and no illustrations were cited in the protologue. The option for designating a neotype for this name appears undesirable, since the very brief description provided by Seubert (1855: 262) is too incomplete and does not permit to unequivocally link this name to any accepted species of Commelina .

Since C. guyanensis does not appear to threaten any currently accepted name, Art. 56.1 does not apply and therefore this name could not be proposed for rejection. Since it is not possible to lectotypify C. guyanensis , there is no basis to neotypify it, and no reason to reject it, this name is here listed as nomem dubium.