Xyris cristata L.A.Nilsson, Kongl. Svenska Vetenskap.-Akad. Handl. 24(14): 56. 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 : 66-67

1. Xyris cristata L.A.Nilsson, Kongl. Svenska Vetenskap.-Akad. Handl. 24(14): 56. 1892.

Type.

“Brasilien”. Bahia "in paludosis ad Itahype flum. Com. Dos Ilheos", Martius s.n. (lectotype, designated here: M! pro parte: plant marked as M0241131). Other: “Brasilien”. Minas Gerais, Vila do Príncipe, "in editis camporum humidis prope V. do Principe ", Martius s.n. (syntype: M! pro parte: plant marked as M0241116).

= Xyris minarum Seub. in Martius, Fl. Bras. 3(1): 215. 1855.

This species is a synonym of X. minarum Seub. Nilsson (1892) cited two syntypes for Xyris cristata in the protologue, both collected by Martius: 1) Martius s.n., from Minas Gerais, Vila do Príncipe, ("in editis camporum humidis prope V. do Principe "), and 2) Martius s.n. from Bahia, "in paludosis ad Itahype flum. Com. Dos Ilheos". However, both collections contain a mixture of species. The sheet from Bahia presents a mixture of Xyris cristata and X. rupicola Kunth, presumably due to their similarity in habit, a common problem in identification of Xyris species. On this sheet, the plants of the two species are marked with different barcodes, X. rupicola (M0241130) and X. cristata (M0241131). The specimen of X. cristata is positioned in the center of the sheet marked with the number “2”, whereas the two specimens positioned laterally and marked “1” correspond to X. rupicola . The material (M0241131) agrees with the description of the species provided in the protologue.

The collection from Minas Gerais includes the other syntype of Xyris cristata , but also plants of a third species, X. subsetigera Malme. The specimens of each species mixed together in this Martius collection agree with their respective protologues and both names are validly published. The mixed collection has been separated into three exsiccatae; the plants of X. subsetigera are now registered as M0241136 and M0241137, whereas that of X. cristata is registered as M0241116. This latter plant is a poor sample of X. cristata , represented only by three peduncles and three spikes.

After studying the two syntypes (M0241131, M0241116), the Bahian collection was selected as the lectotype of Xyris cristata , because it is a more complete specimen.