Reinstatement of the name Petalidium ovatum (Acanthaceae), with an amplified description of the species Author Swanepoel, Wessel 0000-0002-0181-3543 H. G. W. J. Schweickerdt Herbarium, Department of Plant and Soil Sciences, University of Pretoria, Pretoria, 0002 South Africa. School of GeoSciences, Kings Buildings, University of Edinburgh, Edinburgh EH 9 3 FF, United Kingdom. & wessel @ kaokosafari. com; https: // orcid. org / 0000 - 0002 - 0181 - 3543 wessel@kaokosafari.com Author Dexter, Kyle G. 0000-0001-9232-5221 Royal Botanic Garden Edinburgh, 20 a Inverleith Row, Edinburgh EH 3 5 LR, United Kingdom. & kgdexter @ gmail. com; https: // orcid. org / 0000 - 0001 - 9232 - 5221 kgdexter@gmail.com Author Loiseau, Oriane 0000-0002-9852-857X loisoriane @ hotmail. fr; https: // orcid. org / 0000 - 0002 - 9852 - 857 X loisoriane@hotmail.fr Author Van Wyk, Abraham E. 0000-0002-0437-3272 H. G. W. J. Schweickerdt Herbarium, Department of Plant and Soil Sciences, University of Pretoria, Pretoria, 0002 South Africa. School of GeoSciences, Kings Buildings, University of Edinburgh, Edinburgh EH 9 3 FF, United Kingdom. & South African National Biodiversity Institute, Private Bag X 101, Pretoria, 0001 South Africa. & braamvanwyk @ gmail. com; https: // orcid. org / 0000 - 0002 - 0437 - 3272 braamvanwyk@gmail.com text Phytotaxa 2023 2023-11-23 626 3 159 169 https://phytotaxa.mapress.com/pt/article/download/phytotaxa.626.3.2/51307 journal article 278755 10.11646/phytotaxa.626.3.2 5230f489-7a0c-4ca4-9c02-0b7bf96af758 1179-3163 10200302

TABLE 1. Prominent morphological differences between Petalidium ovatum and P. englerianum.

Character	P. ovatum	P. englerianum
Bark (colour on distal	Younger stems: cream-brown	Younger stems: pale grey
stems)	Older stems: brown	Older stems: dark grey or dark grey-brown
Indumentum (vegetative	Dense sessile or short-stalked stellate and longer	Dense sessile or short-stalked stellate trichomes
parts)	dendritic trichomes; not appearing matted	(rarely few dendritic in addition); appearing matted
Leaves	Ovate, rotund or subrotund	Narrowly to broadly elliptic, oblong-elliptic,
(lamina shape)		oblanceolate or rarely ovate
Leaves (lamina apex)	Acute, rounded, emarginate or truncate	Acute, rounded or obtuse
Leaves (lamina base)	Cuneate, rounded, subcordate or truncate	Attenuate, rarely cuneate
Leaves (lamina ratio	1–1.5:1	1.7–3.1:1
length:width)
Leaves (lamina size)	10–51 × 6–38	12–90 × 7–33
(mm)
Bracteoles (shape)	Broadly ovate	Variable: ovate, narrowly obovate, oblanceolate,
		lanceolate or oblong-elliptic
Bracteoles (size) (mm)	10–15 × 7–14	10.5–17.0 × 3.4–13.5
Corolla (upper lobes)	Connate for 45–50% their length	Connate for ca. 20–40% their length
Corolla lobes (colour)	Anterior lobe yellow, dotted burgundy at insertion of	Anterior lobe yellow; other lobes pale yellow or
	trichomes, burgundy towards margins or burgundy	orange, the latter usually fading to brownish orange
	on lateral margins only; other lobes burgundy	in spent flowers
Ovary (indumentum)	Glabrous	Scattered short-stalked glandular trichomes towards
		apex
Distribution	Namibia, Kunene Region from Khorixas to Bergsig	Namibia, Kunene Region to the east of Khorixas;
	in the catchment area of the Huab River (Kaokoveld	Otjozondjupa and Oshikoto Regions and eastwards
	Centre of Endemism)	to northwestern Botswana