Inversodicraea cristata Engl. (Engler 1915: 276)

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 cristata Engl. (Engler 1915: 276)

Ledermanniella cristata (Engl.) C.Cusset ( Cusset 1974: 273)

Type.

CAMEROON • Makaka Station [" Makaka, gr. Steine & Felsen in reissendem Bach im gebirgigen Walde "]; 21 Nov. 1908; [4°55 ’00” N, 9°57 ’00” E]; 500 m; fl.; Ledermann 1173; holotype: B; isotypes: BM [BM000910414], U [U0005650] .

Distribution.

Central African Republic, Cameroon, Equatorial Guinea, Gabon, Angola. This species is known from Gabon by only one collection, N. Hallé 4451, collected in 1968 at the Kinguélé waterfall on the Mbé (Mbei) river in Monts de Cristal. The species is known from at least 15 other collections elsewhere, mainly in Cameroon (12 collections).

Habitat and ecology.

Rapids and falls in rivers from ca 25 to 180 m wide, 5-1500 m in elevation. No information could be found regarding its abundance on sites where it has been found. Flowers and fruits were collected in January, February, and March (in Cameroon and Gabon), in August (in Angola), and in November (Cameroon). Its sole collection from Gabon also contained a few individuals of I. tenax , indicating that both species probably grow intermingled at this site ( Kinguélé waterfalls). Ledermanniella bifurcata (Engl.) C.Cusset and L. letestui were also collected at this site, but no information is provided on the habitat partitioning.

Notes.

According to Cheek et al. (2017), Cusset had a morphologically broad concept of the species. Recent examination by Cheek et al. (2017) of material associated to this species by Cusset revealed that some collections belong to other species, such as Inversodicraea digitata H.E.Hess or I. tchoutoi . Cheek et al. (2017) consider that this species may even be restricted to Cameroon, with records from Equatorial Guinea, Angola, C.A.R., and Gabon representing other species, but they did not examine all collections and did not provide new identifications for the non-Cameroonian collections. Examination of the Gabonese material in Paris did not reveal significant differences from the original description. Hence, we choose to consider the collection N. Hallé 4451 as belonging to I. cristata . Recent inventories were carried out at the Kinguélé waterfall by the authors and colleagues and revealed that the site is now completely devoid of Podostemaceae . The construction of two hydroelectric dams between 1969 and 1978 deeply modified the water availability at the site. Inversodicraea cristata was not collected elsewhere in Gabon.