Dracaena ballyi ( Newton 2004: 11 ) Byng & Christenhusz (2018: 65)

Takawira-Nyenya, Ratidzayi, Thiede, Joachim & Mucina, Ladislav, 2021, New nomenclatural and taxonomic adjustments in Dracaena (Asparagaceae), Phytotaxa 524 (4), pp. 293-300 : 297

Dracaena ballyi ( Newton 2004: 11) Byng & Christenhusz (2018: 65)

Type:— KENYA [Coast Province, Taita District]: Kivuko Hill , soil pockets on rock faces, amongst sedges, and in deeper soil in the shelter of taller vegetation, elev. 180 m, 15 October 1996, Newton 5594 (holotype K 000099514 digital image!, available at: http://specimens. kew.org/herbarium/ K000099514 ; isotype EA000002620 digital image!, available at: https://plants.jstor.org/stable/10.5555/al.ap. specimen.ea000002620) .

≡ Sansevieria ballyi L.E. Newton (2004: 11) .

= Sansevieria ballyi var. robertsoniae L.E.Newton (2015: 11) . Type:— KENYA. Coast Province , Chakama Road, s. d., Newton, Robertson, Stedje & Takawira-Nyenya 5981 (holotype EA) syn. nov.

= Sansevieria tsavoensis Pfennig in Heitz & Zeller (1990: 21) , nomen nudum.

Note:—German botanist Horst Pfennig intended to publish this taxon as S. tsavoensis , but this name remained a nomen nudum according to ICN Article 38.1 ( Turland et al. 2018). The taxon was later published as S. ballyi by Newton (2004) without knowledge of Pfennig‘s intended name, to accomodate dwarf, stoloniferous rosette plants with very short leaves with a distinct rough surface and distinct colour banding and short inflorescences, from south-eastern Kenya. Later, studies by Newton (2010b) and Mansfeld (2016, 2017) showed S. ballyi to be common in south-eastern Kenya and to extend also into adjacent northeast Tanzania. It exhibits a considerable variability in rosette size, leaf length, stolon length, and leaf colour ranging from pale green to almost white with transverse bands varying in width. A population with paler leaf colour and very smooth leaf surface at the northern edge of the species‘ distribution range was first published as a cultivar; Sansevieria ‘Ann Robertson’ ( Newton 2010b: 12) and its pale leaf colour was later concluded to be “normal variation within a species” ( Newton 2010b: 12). Later, the population was elevated to varietal rank as Sansevieria ballyi var. robertsoniae (Newton 2015: 11) . Plants with short, smooth leaves had already been collected back in 1960 by W. Rauh, Heidelberg [D = Deutschland ( Germany)] together with typical plants with rough surface at Mutomo Hills. The smooth-leaved plants were later seen as natural variation by Mansfeld (2017: 33–34). Consequently, S. ballyi var. robertsoniae falls within the range of variation encountered in S. ballyi (var. ballyi ) and therefore it is referred to the synonymy here.

Typification:— The holotype of Sansevieria ballyi at Kew (= K000099514 , see above) designated in the protologue (Newton 2015: 11) is erroneously labelled as “ISOTYPE” on the sheet and in the Kew Herbarium Catalogue (2021) and is wanting at JSTOR Global Plants (https://plants.jstor.org/) .