Inversodicraea paulsitae (C.Cusset) Cheek (Cheek and Haba 2016: 55)

Bidault, Ehoarn, Boupoya, Archange, Ikabanga, Davy U., Nguimbit, Igor, Texier, Nicolas, Rutishauser, Rolf, Mesterhazy, Attila & Stevart, Tariq, 2023, Novitates Gabonenses 93: a fresh look at Podostemaceae in Gabon following recent inventories, with a new combination for Ledermanniella nicolasii, Plant Ecology and Evolution 156 (1), pp. 59-84 : 59

Inversodicraea paulsitae (C.Cusset) Cheek (Cheek and Haba 2016: 55)

Figs 3F, G , 4B

Ledermanniella paulsitae C.Cusset ( Cusset 1983: 378, plate 7)

Type.

GABON • Litsila rapids on the Ngounié river, at Moupoundi ["Moupoundi, rapide Litsila de la Ngounye "]; 20 Jun. 1927; [2°25 ’00” S, 11°50 ’00” E]; 250 m; fl., fr.; Le Testu 6510; holotype: P [P00179346]; isotype: BR [BR0000006265069] .

Distribution.

Gabon, Republic of the Congo. This species is only known from southern Gabon in the Ngounié and Louétsi rivers, and the Bibaka and Bouenza rivers in the Republic of the Congo.

Habitat and ecology.

Rapids and falls in large rivers from ca 50 to 80 m wide, 150-580 m in elevation. It appears to be quite abundant at the few sites where it has been encountered. Flowers and fruits were collected in January, June, and August. Grows intermingled with Inversodicraea annithomae and I. boumiensis in the Louetsi river. This species was solely found in micro-habitats submitted to strong currents.

Notes.

Before 2017, this species was only known from two collections in Gabon (in 1927 and 1933), and two in the Republic of the Congo (in 1965 and 1975). One of the Gabonese collections was made at the Byoko falls on the “Louétoie” river, that presumably corresponds to the Bongolo falls on the Louetsi river, near Lébamba, a site that was recently explored by authors and colleagues, but without any success. A small hydroelectric facility was built downstream of these rapids, which might have caused the disappearance of this species’ subpopulation. Another species was nevertheless collected at this site, suggesting that I. paulsitae may be less resilient to disturbances and may have been replaced. This hypothesis remains speculative until a complete inventory of these rapids is undertaken. Recent inventories made in the Ngounié river did not collect this species, but the exploration of this major Gabonese river remains largely fragmentary.

Figures

Figure 3. Photographs illustrating a selection of species treated in this paper. A, B. Inversodicraea annithomae (A: Boupoya et al. 2444; B: Boupoya et al. 2689). C. Inversodicraea boumiensis (Boupoya et al. 1748). D, E. Inversodicraea nicolasii (D: Texier et al. 2247; E: Texier et al. 2334). F, G. Inversodicraea paulsitae (Boupoya et al. 1750). H, I. Inversodicraea tenax (H: Boupoya et al. 2432; I: Boupoya et al. 2430). Photographs: Igor Nguimbit (A), Archange Boupoya (B, C, F-I), Nicolas Texier (D, E).

Figure 4. Distribution maps of Podostemaceae in Gabon. A. Inversodicraea annithomae (grey circles), I. boumiensis (red diamonds). B. Inversodicraea nicolasii (red diamonds), I. paulsitae (grey circles), I. tenax (orange triangles). C. Inversodicraea thollonii (red diamonds), Ledermanniella bifurcata (grey circles). D. Ledermanniella aloides (grey circles), L. schlechteri (red diamonds).