Wednesday, December 13, 2017

[Botany • 2017] Revised Treatment of Mozambican Memecylon (Melastomataceae — Olisbeoideae), with Descriptions of Four New Species in Memecylon section Buxifolia


Memecylon incisilobum  R.D. Stone & I.G. Mona

in Stone, Mona & Ramdhani, 2017 

Abstract

Memecylon sect. Buxifolia R.D. Stone (Melastomataceae, Olisbeoideae) is a group of forest shrubs and small understory trees distributed from tropical East Africa (Kenya and Tanzania) to eastern South Africa and with a disjunct occurrence in Madagascar. Previous authors had recognized three species of this section as occurring in Mozambique, i.e., M. natalense Markgr., M. torrei A. Fern. & R. Fern. and M. insulare A. Fern. & R. Fern. Here we describe four new species of M. sect. Buxifolia from Mozambique and adjacent parts of Malawi and Tanzania: Memecylon incisilobum R.D. Stone & I.G. Mona, M. nubigenum R.D. Stone & I.G. Mona, M. rovumense R.D. Stone & I.G. Mona and M. aenigmaticum R.D. Stone. In accordance with previous molecular results, M. incisilobum and M. nubigenum are semi-cryptic species that had been confused with M. natalense (considered here to be a South African endemic). Memecylon rovumense and M. aenigmaticum had also been confused with M. natalense, but their conspicuously verrucose-wrinkled fruits indicate a closer affinity with M. torrei. We assess the conservation status of each new species according to the IUCN Categories and Criteria, and provide an identification key to the seven species of Memecylon currently recognized in the flora of Mozambique.

Keywords: Eudicots, Africa, Melastomataceae, Memecylon, Mozambique, new species, plant conservation, plant taxonomy


FIGURE 2. Memecylon incisilobum.
A
. Leafy branchlet; B. Trunk showing character of the bark. C. Flower. D. Fruiting branchlet.

Photographs in A–C by John Burrows; in D by Hermenegildo Matimele.

Memecylon incisilobum R.D. Stone & I.G. Mona, sp. nov.

Etymology:—The epithet incisilobum is an adjective referring to the incised calyx-lobes, this being one of the main features distinguishing this species from M. natalense.


Memecylon nubigenum R.D. Stone & I.G. Mona, sp. nov.  

Etymology:—The epithet nubigenum is a compound derived from the Latin noun nubis meaning “cloud” and the verb gignere meaning “to be born.” It functions as an adjective and means “born of or originating from the clouds.” It is a reference to the habitat in mountains of northern Mozambique and southern Malawi.


Memecylon rovumense R.D. Stone & I.G. Mona, sp. nov.  

Etymology:—The epithet rovumense is an adjective used to indicate geographical origin, i.e., to emphasize that the new species is an endemic of the Rovuma region of northern Mozambique and southeastern Tanzania. The region itself gets its name from the Rovuma River which forms the border between these two countries.


Memecylon aenigmaticum R.D. Stone, sp. nov. 

Etymology:—The epithet aenigmaticum is an adjective based on the Greek noun ainigma meaning mysterious or difficult to interpret or understand. It is in reference to the fact that this new species has been previously confused with both M. natalense and M. rovumense (q.v.).


Robert Douglas Stone, Imercia Gracious Mona and Syd Ramdhani. 2017. Revised Treatment of Mozambican Memecylon (Melastomataceae—Olisbeoideae), with Descriptions of Four New Species in M. section BuxifoliaPhytotaxa.  331(2); 151–168.  DOI: 10.11646/phytotaxa.331.2.1