Sphaerostephanos unitus

Mezonda, C. P. J., Simão, I., Silva, H. & Silveira, P., 2020, New records for the fern and lycophytes flora of Uíge, Northern Angola, Phytotaxa 442 (1), pp. 1-10 : 8

** Sphaerostephanos unitus (L.) Holttum (1974: 165)

Polypodium unitum Linnaeus (1759: 1326)

Terrestrial fern. Elev. in Uíge: 1201–1213 m. In rocky areas and near roads. Distribution in Angola: Uíge. Global distribution: from W-Pacific, through Australia, Indonesia, Philippines, Malaysia, India, Madagascar, Eastern Africa to Angola.

Collections : Surroundings of Mucaba [7°25’53” S, 15°10’01” E], 05-08-2018, Mezonda, Dos Santos & Mani, 17 ; 07-12-2018, Mezonda, Mani & Barros 42 ( COI) .

Diversity and novelty of the results

From the 19 taxa identified, 14 (73.7%) are new records for the province of Uíge. These include five new records for the family Thelypteridaceae : Christella dentata , C. microbasis , Pneumatopteris afra , Pseudocyclosorus pulcher , and Sphaerostephanos unitus var. unitus ( Table 1); three new records for the Pteridaceae family, which are Pityrogramma calomelanos var. calomelanos , Pteris catoptera var. catoptera and Pteris vittata ; two new records for the Nephrolepidaceae : Nephrolepis biserrata and Nephrolepis undulata ; and, finally, the following families are represented only by one taxon: Tectariaceae with Tectaria gemmifera , Dennstaedtiaceae with Pteridium aquilinum subsp. centrali-africanum, Dryopteridaceae with Parapolystichum currorii , and Gleicheniaceae with Dicranopteris linearis .

These results represent a significant increase, with the total number of taxa known for this province rising from 24 to 38 taxa. However, this seems to remain a relatively low diversity when we compare it with nearby Angolan provinces like Cuanza Norte, immediately south to the Uíge province, whose diversity in terms of ferns and allies is much bigger, with 74 species, 4 varieties and 2 subspecies included in 42 genera and 22 families. To the north of Uíge province, Cabinda possesses 49 taxa included in 29 genera and 19 families ( Roux 2006, 2008). These differences in the number of taxa may be just a consequence of the lack of studies both in the municipality and province of Uíge, since, as can be seen in Dauby et al. (2017: fig. 5.2; http:rainbio.cesab.org), Cabinda and Cuanza Norte seem to have been more intensely studied than Uíge. Alternatively, this might also be due to the more extensive patches of moist vegetation that can be found in Cabinda and Cuanza Norte. However, in conclusion, this study highlights the need for further floristic studies in the region, which should have many benefits, including a contribution for the management of the local biological resources.