Pycreus sanguineosquamatus Van der Veken (1955: 145)

Don, Bel Lar Ri, Ers, Enne Th Ba Ut & Reynde, Ma Rc, 2014, Taxonomic changes in C Cyperus (Cypereae, Cyperoideae, Cyperaceae): combining the sedge genera Ascolepis, Kyllinga and Pycreus into Cyperus s. l., Phytotaxa 166 (1), pp. 33-48 : 43

Pycreus sanguineosquamatus Van der Veken (1955: 145) .

Type:— DEMOCRATIC REPUBLIC OF CONGO,

May 1939, H. Bredo 2750 (holotype BR!, isotypes BR!, C!, NY!, P!, PRE!).

= Cyperus fontinalis (Cherm.) Kükenthal (1935 –36: 341)

Basionym: Pycreus fontinalis Cherm., Bull. Soc. Bot. France 67: 327 (Chermezon 1920 publ. 1921). Type:— MADAGASCAR,

March 1920, H. Perrier de la Bâthie 13056 (holotype P!, isotypes K!, P!).

Description: — Kükenthal (1935 –36: 341).

Note: — Pycreus fontinalis is a rare species only known from its type locality near the hot water springs of Antsirabe , Madagascar. Pycreus sanguineosquamatus is described on material from salt marshes of volcanic origin in the region of Shaba ( Democratic Republic of Congo). With the description of the latter species, Van der Veken (1955) already noted the similarity of this taxon with P. fontinalis . However , P. fontinalis was circumscribed by Chermezon (1920 publ. 1921) and (1935–36) as having a tiny rhizome. As Van der Veken (1955) interpreted the material from Congo as therophytic, the two species were assumed to be separated by their growth form. However , when comparing the type material of both taxa, this distinction of growth forms is, in our opinion, no more than a matter of interpretation as no striking differences could be observed between the plant bases of the Congolean and Malagasy material. In addition, glumes and nutlets (the taxonomically most important characteristics in this group of Cyperus ) are very similar. The type locality of Cyperus fontinalis in Antsirabe seems to have been destroyed due to exploitation of the hot water from the springs by the local community and the species may even be locally extinct (field observations in Madagascar, April 2010). The salt marches in southern Congo are similarly being exploited. The salt marshes of this region are of volcanic origin and provide a habitat to a large number of endemic plant species that are adapted to the mineral rich soils ( Symoens 1953) such as several short lived (endemic) Cyperus and Bulbostylis species. Considering the strongly local geographic distribution of the species (two known localities) with a possible extinction from Antsirabe, small number of plants and continuing human exploitation at both localities, we propose to give Cyperus fontinalis the status of Critically Endangered according to the IUCN categories and criteria ( IUCN 2012) .