Cyperus arenarius Retzius (1786:9)

Muhsina, Abdul Azeez & Maya, Chandrasekharan Nair, 2025, Nomenclatural notes and typification of Retzius names in the genus Cyperus (Cyperaceae), Phytotaxa 712 (1), pp. 47-58 : 48

Cyperus arenarius Retzius (1786:9)

Lectotype (Step I. Fischer 1932. Step II. designated here):— INDIA: India Orientalis, s.d., Koenig, s.n., ( LD, LD1284527 , digital image!) ( Fig. 1 ); isolectotypes: [ LD, LD1291067 ; BM, BM000901278 , BM000901279 ; C, C10010128 digital images!].

Retzius proposed the name C. arenarius based on the collection made by Koenig from India Orientalis. Fischer (1932) in the article ‘The Koenig Collection in the Lund Herbarium’ listed out the name C. arenarius in bold letters, and this implies that Koenig’s collection of C. arenariu s in Lund Herbarium is the type of C. arenarius Retz. But , in Lund Herbarium, there were two sheets of Koenig’s collection (LD1284527 & LD1291067).

Vare (2006) designated the sheet LD1284527 as isolectotype as part of the lectotypification of Cyperus section Arenarii . While designating the type, he selected lectotype from BM Herbarium, and there are two sheets of Koenig’s collection in the BM Herbarium too, viz. BM000901279, which is selected as lectotype and BM000901278 was labelled as isolectotype. While doing this lectotypification, he mentioned the sheets in LD but did not consider the explanation in the publication ‘The Koenig Collection in the Lund Herbarium’, which ought to be considered for typification. Further, Vare (2006) failed to cite the herbarium sheet C10010128 housed at Copenhagen Herbarium. Hence, Vare’s attempt is to be superseded and seems invalid.

Hence, the second step lectotypification is being done here with LD1284527 as lectotype, as this is the most probable sheet that might have been seen by Retzius while describing the taxon and the other sheet, viz. LD1291067 is an isolectotype.

In the sheet LD1284527, there are three specimens mounted on and are labelled as (1), (2) and (3) ( Figure 1.A ), of which, the better-preserved one is the specimen mounted on the extreme left side (labelled as (1)) and is designated here as lectotype. Further original materials are BM000901279, BM000901278 and C10010128, which are to be treated as isolectotypes.

Figures

FIGURE 1. A. Digital image of the proposed Lectotype of Cyperus arenarius Retz. (LD1284527) B. Reverse side of the sheet © Lund Herbarium, reproduced with permission.