Xyris regnellii L.A.Nilsson, Kongl. Svenska Vetenskap.-Akad. Handl. 24(14): 43. 1892.

Wanderley, Maria das Gracas Lapa, 2017, Typification of binomials in Xyris section Nematopus (Xyridaceae) published by L. A. Nilsson, PhytoKeys 80, pp. 65-76 : 70-71

11. Xyris regnellii L.A.Nilsson, Kongl. Svenska Vetenskap.-Akad. Handl. 24(14): 43. 1892.

Type.

“Brasilien”.

In the protologue of the species, Nilsson (1892) cited two different collections from the same location ( Brazil, Minas Gerais, Caldas) under the same number Regnell III 2050. The two collections can be recognized by the annotations referred to in the protologue: 1) "In palude inter gramineas alta", and 2) "loco paludoso in consortione graminearum excelsiorum". The sheets examined in the present study at P, S and UPS have different dates on their labels for this same collection - no dates are mentioned in the protologue. This variation of dates and other label information on the duplicate sheets of the type collection led to a more detailed analysis of the typification of this name, involving visits to both Swedish herbaria (UPS and S) and P, where the duplicates of the Regnell III 2050 are deposited. Smith and Downs (1968) previously indicated as lectotype the sheet deposited in S (S-R-6609), and since this is representative of the species and protologue, it is confirmed here as the lectotype. It can also be recognized by the citation in the protologue ( “Brasilien”, Minas Gerais, Caldas, Regnell III 2050); its label includes the date 10-01-1880. The isolectotype is deposited in UPS ( Regnell III 2050) and has the same date as the lectotype (10-I-1880), includes a short description of the species (in pencil with similar handwriting to that of Nilsson), and the ecological description "in palude inter gramineas alta", as cited in the protologue. Although the latter information does not appear on the lectotype sheet at S, there is no doubt that they are duplicates and that they complement each other in relation to the protologue. The syntype at UPS corresponds to the second material mentioned in the Regnell III 2050 protologue ("loco paludoso in consortione graminearum excelsiorum"), and this sheet includes two dates: 20-I-1880 and 17-2-1880. It also has a brief description of the species and fragments of material in envelopes, indicating that they were examined by Nilsson when he prepared his original description. This material is thus very informative and complementary for interpreting this species name .

The P01676114 collection at Paris (P) is part of the type collection of Xyris regnellii ( Regnell III 2050), and can be considered as a syntype, but only in part (pro parte), as it consists of a mixture of specimens of Xyris regnellii and X. filifolia . This sheet does not have a date of collection or any of the other information mentioned above, showing only the collector’s name and number. It is, however, the only reference to X. regnellii currently available on the JSTOR Global Plants ( Ithaka 2015) website for type materials. Another specimen at P (P01727365), is possibly part of the type collection of Xyris regnellii , but as the number of the Regnell collection has not been recorded, it has not been included here in the above citation of duplicates of the type collection. Yet another P specimen, P01676128, which is of X. regnellii , was not considered for typification of the name, because it is labelled as X. filifolia and is a different collection ( Regnell III 2051). The interpretation of Xyris regnellii and X. filifolia type material, described by Nilsson (1892) in the same work, was made more difficult as they were collected by Regnell in the same location (Minas Gerais, Caldas), and received consecutive numbers: Regnell III 2050 for Xyris regnellii , and Regnell III 2051 for X. filifolia . The mixture of material of these two species in the duplicates at P and the exchange of labels between them must have occurred during the original distribution of duplicates.