Inversodicraea boumiensis (C.Cusset) Cheek

Tchouto, P. & Burgt, X. van der, 2017, A synoptic revision of Inversodicraea (Podostemaceae), Blumea 62 (2), pp. 125-156 : 134-135

3. Inversodicraea boumiensis (C.Cusset) Cheek

Inversodicraea boumiensis (C.Cusset) Cheek in Cheek & Haba (2016a) 2. — Ledermanniella boumiensis C. Cusset (1983) 370. — Type: Le Testu 6536 (holotype P00179270 image; isotype P00179271 image), Gabon, Mbigou, Chutes de Boumi, fl., fr., 5 July 1927.

Etymology. Named for the Boumi Falls of Gabon,only known location for the species.

Distribution — Gabon. Known only from the type.

Habitat & Ecology — Rapids; 600–700 m altitude.

Conservation — Inversodicraea boumiensis is listed on www.iucnredlist.org as VU D2 (Vulnerable). It was assessed in 2007 ( Ghogue 2010c). Cheek ( Onana & Cheek 2011) as- sesses it as EN B2 ab(iii), that is Endangered. However, both assessments follow the protologue ( Cusset 1983) which as- serts that the species occurs at the Ntem Falls of Cameroon as well as the type locality in Gabon. Yet, the plants at Ntem ascribed to this species are shown in this paper to be I. tchoutoi (see that species). Currently the species is known only from the type locality, falls near Mbigou on the Boumi, a tributary of the Ngounié River in the Province of that name. Assigning an area of occupancy to this species of 1 km 2 would result in an assessment of Critically Endangered, CR B2 ab(iii) if any threat were known or to appear. Since we know of no threats at either of these two localities, the species is here assessed as Near Threatened.

Notes — In describing this species, Cusset (1983) cited Letouzey 15339 from the Ntem River in Cameroon in addition to the type from Gabon. Examination of this Letouzey specimen at YA showed it to be I. tchoutoi (see discussion under that species). Therefore, I. boumiensis is known only from Gabon. Inversodicrea boumiensis resembles I. gabonensis , the type of which was collected within some tens of kilometres. They differ in that the first has pollen in dyads from flowers with two stamens, while I. gabonensis has monads and one stamen.