taxonID	type	description	language	source
03A587D206739903FF1A1C5BFDCC64C7.taxon	diagnosis	Diagnosis: — A woody shrub or tree up to 8 m tall, morphologically and genetically most similar to Zanthoxylum chalybeum and previously mistaken for Z. ovatifoliolatum, both from which it differs in having branches puberulous, leaflets glabrous or with widely spaced tortuous trichomes and / or indumentum sparsely puberulous on veining, inflorescence axes puberulous (vs. branches glabrous, leaflets glabrous [Zanthoxylum chalybeum var. chalybeum] or tomentose [Zanthoxylum chalybeum var. molle], inflorescence axes glabrous); gynoecium 1 - or 2 - carpellate (vs. only 1 - carpellate). It furthermore differs from Z. ovatifoliolatum in the curved prickles (vs. nearly straight), leaflets (1) 3 – 5 - jugate (vs. 2 - or 3 - jugate), leaflet apices acute or obtuse (vs. acuminate), leaflet size on a given leaf either uniform, slightly increasing or decreasing towards the tip, or with the terminal pair notably shorter than the others (vs. a consistent increase in size towards the tip), and calyx lobes deltoid (vs. suborbicular).	en	Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, Van Wyk, Abraham E. (2025): Zanthoxylum kaokoense (Rutaceae: Zanthoxyloideae), a new species from Angola and Namibia. Phytotaxa 726 (4): 281-290, DOI: 10.11646/phytotaxa.726.4.5, URL: https://doi.org/10.11646/phytotaxa.726.4.5
03A587D206739903FF1A1C5BFDCC64C7.taxon	materials_examined	Type: — NAMIBIA. Kunene Region: 1813 (Opuwo), Otjomatemba Pass, ca. 8 km south of Otjomatemba on road C 43, (– DD), 1207 m a. s. l., 12 January 2025, Swanepoel 656 (holotype WIND!; isotypes PRE!, PRU!).	en	Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, Van Wyk, Abraham E. (2025): Zanthoxylum kaokoense (Rutaceae: Zanthoxyloideae), a new species from Angola and Namibia. Phytotaxa 726 (4): 281-290, DOI: 10.11646/phytotaxa.726.4.5, URL: https://doi.org/10.11646/phytotaxa.726.4.5
03A587D206739903FF1A1C5BFDCC64C7.taxon	description	Illustrations: — Curtis & Mannheimer (2005: 257, as Zanthoxylum ovatifoliatum, line drawing of shoot with leaves and fruit); Mannheimer & Curtis (2018: 195, as Zanthoxylum ovatifoliatum, photographs of habit, prickles, stem, and leaves). Dioecious shrub or tree up to 8 m tall; single or multi-stemmed from below or just above ground level, stems up to 120 mm in diam., aculeate, prickles recurved, up to 12 mm long, black, dark brown or grey, puberulous initially, glabrescent, terminal buds protected by deltoid scales, indumentum puberulous to villous, light brown, bark irregularly longitudinally ridged, grey, dark grey or grey-brown, black-dotted on older branches, ridges often paler coloured, puberulous, often with few longer tortuous simple trichomes in addition, glabrescent. Leaves alternate and spirally on new shoots, whorled on brachyblasts, up to 180 mm long; petiole flattened adaxially towards base, 15 – 45 mm long; rachis 20 – 95 mm long, leaflets opposite to subopposite, sessile or subsessile, (1) 3 – 5 - jugate, leaflets papyraceous, all pairs on a specific leaf of similar length or slightly increasing towards distal end or vice versa, or distal pair markedly shorter than others; lamina narrowly ovate, ovate-elliptic or elliptic, 7 – 70 × 4 – 35 mm, apex acute or obtuse, base obtuseacute, obtuse, rounded or that of terminal one sometimes cuneate, sub-conduplicate, sometimes asymmetrical and / or oblique, margins crenulate or crenulate-serrulate, with single orbicular secretory cavity (pellucid gland) in all sinuses, sparsely (<5 / cm 2) to densely (up to> 50 / cm 2) scattered throughout rest of lamina, discolorous, green adaxially, paler abaxially, glabrous or with widely spaced tortuous trichomes including on margins, sometimes sparsely puberulous on veining, crushed leaves aromatic, aroma citrus-like, midrib prominently raised on both sides, 3 – 9 principal lateral vein pairs prominent adaxially; petioles, rachises and midribs puberulous, often with few longer tortuous simple trichomes in addition, aculeate (on midribs abaxially only, sometimes lacking), prickles up to 4 mm long, curved, green, reddish brown, brown or black. Inflorescences (female plants — male plants not seen) at the base of new branches below leaves or terminally on brachyblasts, whorled, paniculate or racemose-paniculate, peduncle 3 – 14 mm long, rachis straight, 7 – 45 mm long, puberulous often with few longer tortuous simple trichomes in addition, bracts narrowly triangular, up to 1.5 × 0.4 mm, cobwebby, trichomes pale brown. Flowers 4 - or 5 - merous on pedicel ca. 0.6 mm long. Calyx shallowly cupular, tube ca. 1 mm long, lobes deltoid, ca. 0.5 × 0.5 mm, sparsely ciliate, glandular abaxially, persistent on the fruit. Petals imbricate, narrowly ovate or oblong-elliptic, ca. clawed, apices acute or obtuse, sometimes incurved, ca. 3.2 × 1.2 – 1.6 mm, cream-yellow, darker in centre, margins pellucid with widely spaced papillae or papillae absent. Staminodes vestigial, reduced to the aborted anthers, inserted at the base of a disc. Disc cushion-shaped, pale yellow, ca. 0.3 mm high. Gynoecium borne on the disc, 1 - or 2 - carpellate, ca. 1.8 mm long, glabrous; 2 - carpellate ovary (“ ovariole ”) proximally connate and stylodia usually joined in a common style or at least with joined stigmas, bilobed, 2 - locular; 1 - carpellate ovaries subglobose, ca. 0.8 mm long, prominently ridged, 1 locular; each locule 2 - ovulate (1 aborts); style terete, oblique, incurved, ca. 0.4 mm long, grooved; stigma discoid, 0.6 – 0.8 mm diam., yellowish green, turning black with age. Fruit a subglobose or globose follicle (carpels separating in fruit), dehiscent, ca. 8 mm diam., subsessile, glandular-foveolate or glandular-verrucose, reddish brown; seed subglobose, 4 – 6 mm diam., black, smooth, shiny.	en	Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, Van Wyk, Abraham E. (2025): Zanthoxylum kaokoense (Rutaceae: Zanthoxyloideae), a new species from Angola and Namibia. Phytotaxa 726 (4): 281-290, DOI: 10.11646/phytotaxa.726.4.5, URL: https://doi.org/10.11646/phytotaxa.726.4.5
03A587D206739903FF1A1C5BFDCC64C7.taxon	biology_ecology	Phenology: — Flowers and fruit have been recorded from March to June.	en	Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, Van Wyk, Abraham E. (2025): Zanthoxylum kaokoense (Rutaceae: Zanthoxyloideae), a new species from Angola and Namibia. Phytotaxa 726 (4): 281-290, DOI: 10.11646/phytotaxa.726.4.5, URL: https://doi.org/10.11646/phytotaxa.726.4.5
03A587D206739903FF1A1C5BFDCC64C7.taxon	distribution	Distribution and habitat: — In Angola, Zanthoxylum kaokoense is currently known only from three localities (near Caraculo, the Tchamalindi Mountain and the Viluoviaengua Mountain), but is more widespread in northwestern Namibia, from the mountainous area bordering the Kunene River southwards to near Sesfontein (Fig. 3). Zanthoxylum kaokoense occurs on arid hillsides, plains and along drainage lines and ephemeral riverbeds at elevations of 500 – 1700 m a. s. l., 50 – 200 km inland from the Atlantic Ocean. The region receives approximately 100 – 350 mm of annual rainfall, mostly during the summer months (Atlas of Namibia Team 2022, Mendelsohn & Huntley 2023).	en	Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, Van Wyk, Abraham E. (2025): Zanthoxylum kaokoense (Rutaceae: Zanthoxyloideae), a new species from Angola and Namibia. Phytotaxa 726 (4): 281-290, DOI: 10.11646/phytotaxa.726.4.5, URL: https://doi.org/10.11646/phytotaxa.726.4.5
03A587D206739903FF1A1C5BFDCC64C7.taxon	conservation	Conservation status: — Zanthoxylum kaokoense has been recorded at 18 localities where it is uncommon to rare. The extent of occurrence (EOO) has been calculated as 29716 km ² and the area of occupancy (AOO) as 76 km ², based on a cell width of 2 km, as recommended by the IUCN Standards and Petitions Committee (2024). Although Zanthoxylum kaokoense has a limited geographical range (AOO <2000 km ²) and a continuing decline is projected due to its habitat being under pressure from prolonged droughts, it is known from more than five locations. It therefore does not qualify for the Vulnerable (VU) category and is here provisionally assessed as Least Concern (LC) (IUCN 2012).	en	Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, Van Wyk, Abraham E. (2025): Zanthoxylum kaokoense (Rutaceae: Zanthoxyloideae), a new species from Angola and Namibia. Phytotaxa 726 (4): 281-290, DOI: 10.11646/phytotaxa.726.4.5, URL: https://doi.org/10.11646/phytotaxa.726.4.5
03A587D206739903FF1A1C5BFDCC64C7.taxon	etymology	Etymology: — The specific epithet refers to the Kaokoveld in northwestern Namibia, a region forming part of the Kaokoveld Centre of Endemism (Van Wyk & Smith 2001, Craven 2009). This biogeographically well-defined region extends into southwestern Angola. Zanthoxylum kaokoense is endemic to the Kaokoveld Centre.	en	Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, Van Wyk, Abraham E. (2025): Zanthoxylum kaokoense (Rutaceae: Zanthoxyloideae), a new species from Angola and Namibia. Phytotaxa 726 (4): 281-290, DOI: 10.11646/phytotaxa.726.4.5, URL: https://doi.org/10.11646/phytotaxa.726.4.5
03A587D206739903FF1A1C5BFDCC64C7.taxon	vernacular_names	Common names and uses: — English vernacular names in use for Zanthoxylum kaokoense are “ Ovambo knobwood ” and “ Kaoko knobwood ”, and Afrikaans names are ovamboknophout and ovamboperdepram (Van Wyk et al. 2011). The first mentioned English and Afrikaans names are the ones recommended by the Dendrological Society of South Africa (Von Dürckheim et al. 2014). In Namibia preference is given to nokoma, the Khoekhoegowab (Nama) name for the species. In Otjiherero (Herero), the language spoken by the majority of people within the species’ sparsely populated range, local names include ohandua, ohandwa, omuhandu, and omuhandwa (Van Wyk et al. 2011). The species is well known among local communities for its biocultural significance. According to Mannheimer and Curtis (2018), the roots are commonly traded through barter, and the dried, powdered fruit is used as a cosmetic. Additionally, an infusion made from the fruit is used to treat various ailments in both humans and animals, particularly for stomach-related complaints (Von Koenen 1996, Mannheimer & Curtis 2018).	en	Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, Van Wyk, Abraham E. (2025): Zanthoxylum kaokoense (Rutaceae: Zanthoxyloideae), a new species from Angola and Namibia. Phytotaxa 726 (4): 281-290, DOI: 10.11646/phytotaxa.726.4.5, URL: https://doi.org/10.11646/phytotaxa.726.4.5
03A587D206739903FF1A1C5BFDCC64C7.taxon	discussion	Notes: — Zanthoxylum kaokoense is morphologically and genetically most similar to Z. chalybeum. However, in herbarium collections, the new species has so far been misidentified as Zanthoxylum ovatifoliolatum (Fig. 4). Hence these three species were compared in the diagnosis above. Some of the morphological features to distinguish between Z. kaokoense, Z. chalybeum, and Z. ovatifoliolatum are also provided in Table 1. In existing phylogenetic studies of Zanthoxylum (Appelhans et al. 2018, Reichelt et al. 2021), material from the gathering Swanepoel SWA 3 / 76 (housed at US), was used for sequencing under the name Z. ovatifoliolatum. However, this specimen is actually Z. kaokoense and originates from the same population in Namibia as its type specimen. As a result, Z. ovatifoliolatum was not sequenced, nor were any of the other Angolan species of Zanthoxylum. The type gathering of Z. ovatifoliolatum (Welwitsch 4561, specimens housed at Herbs BM, COI, G, LISC, and K; see Fig. 4) comes from Morro de Lopol (l) o — a hill near the modern-day town of Huila in Angola — which lies well outside the Kaokoveld Centre (Figueiredo & Smith 2020; E. Figueiredo, pers. comm.). This locality (Fig. 3) is situated on the Huila Plateau, approximately 100 km east of Caraculo and 240 km north-northeast of Tchamalindi Mountain and Serra Viluoviaengua, the only known sites for Z. kaokoense in Angola. Given our view that Z. ovatifoliolatum is not conspecific with Z. kaokoense, and considering that the name Z. ovatifoliolatum has largely been applied to what we now describe as Z. kaokoense, questions naturally arise regarding its true taxonomic status. A search conducted near the type locality by one of us (WS) in February 2023 failed to locate any Zanthoxylum specimens. Beyond the type gathering of Z. ovatifoliolatum — and its later synonym Z. citriodorum Welw. ex Hiern (1896: 114) — represented by Welwitsch 4561 (Fig. 4), we have encountered only one additional collection that resembles the type: Azancot de Menezes 580, housed in Herb K (K 004663896; accessed via GBIF). This specimen originates from Tchimbolelo near Chimbemba in Angola, also within Huila Province and approximately 100 km southeast of the type locality (Fig. 3). These findings suggest that within Angola, Z. ovatifoliolatum is likely restricted to Huila Province. The species’ inland distribution and apparent association with relatively high-rainfall savannah raise two possibilities: it may either represent a distinct, Angolan endemic species, or it could be an outlier population of Z. chalybeum, a species recorded further east in Zambia and Zimbabwe (and extending further north in Africa) and with which it shares morphological similarities (Table 1). If the latter scenario proves correct, the name Z. ovatifoliolatum — validly published in 1896 — would become a synonym of Z. chalybeum, which was published slightly earlier in 1895. However, it is too early to make a definitive taxonomic decision. Further detailed comparisons and targeted fieldwork in Angola are essential before the true status of Z. ovatifoliolatum can be confidently resolved.	en	Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, Van Wyk, Abraham E. (2025): Zanthoxylum kaokoense (Rutaceae: Zanthoxyloideae), a new species from Angola and Namibia. Phytotaxa 726 (4): 281-290, DOI: 10.11646/phytotaxa.726.4.5, URL: https://doi.org/10.11646/phytotaxa.726.4.5
03A587D206739903FF1A1C5BFDCC64C7.taxon	materials_examined	Additional specimens examined (paratypes): — ANGOLA, Namibe Province: — Moçamedes: Dois Irmãos, Caraculo, 1512 BA, 9 May 1962, Santos 1040 (LISC!); Serra Tchamalindi, eastern part of range, 1612 DD, 1659 m, 26 April 2021, De Cauwer TCH 1 - 28 (LUBA!); Serra Viluoviaengua, ca. 35 km south-southeast of Oncocua in drainage line, 1613 DC, 883 m, 17 June 2025, Swanepoel 664 (LUBA!, PRU!) NAMIBIA, Kunene Region: — Baynes Mountains, 1712 BB, 3 April 2003, Burke 03077 (WIND!); 57 km west of Okangwati on track to Otjitanda, 1712 DB, 1400 m, 3 June 2006, Kolberg & Tholkes 1984 (WIND!); 3.5 miles north of Ohopoho, 1813 BB, 29 March 1957, De Winter & Leistner 5254 (PRE!, WIND!): 4 km nördlich Ohopoho, 1813 BB, 8 April 1973, Giess & Van der Walt 12642 (PRE!, WIND!); 5 km noord van Okarosave, 1813 BB, 23 June 1977, Viljoen 409 (WIND!); Road from Opuwo to Sesfontein, 1813 BB, 10 April 2000, Curtis CUR 410 (WIND!); 18 km west of Kaoko Otavi on track to Orupembe, 1813 BC, 1000 m, 11 June 2001, Kolberg, Loots & Moses HK 1150 (WIND!); Quarty [Quartz?] outcrop ± 100 m south of camp site, 1813 BC, 1203 m, 30 March 2002, Curtis, Aronson & Le Floc’h CUR 1640 (WIND!); Orumana, 1813 BD, 30 January 1968, Grobbelaar 45 (WIND!); 18 ° 52 ’ 30 ” south and 13 ° 52 ’ 30 ” east, 1813 DD, 20 February 1999, Tagg & Neuhaus JT 5 (WIND!); 12 km south of Otjomatemba, 1813 DD, 1160 m, 4 January 2004, Swanepoel SWA 3 / 76 (WIND!); 18 ° 52 ’ 6 ’’ south and 14 ° 22 ’ 4 ” east, 1814 CD, 4 April 2000, Curtis CUR 346 (WIND!); Kaokoveld. Ondore, late 1957, Abner 64 (PRE!, WIND!); Kaokoveld. Near Ohopoho, 20 May 1961, Gibson 80 (WIND!); Joubert-Berge südlich Ohopoho, 6 June 1963, Giess & Leippert 7376 (WIND!); Kaokoveld. In deep gorge on road between Sesfontein and Kaoko Otavi, January 1968, Tinley 1669 (WIND!); Kaokoveld. Oruandje, 6 January 1973, Owen-Smith 149 (WIND!).	en	Swanepoel, Wessel, Becker, Rolf, Cauwer, Vera De, Van Wyk, Abraham E. (2025): Zanthoxylum kaokoense (Rutaceae: Zanthoxyloideae), a new species from Angola and Namibia. Phytotaxa 726 (4): 281-290, DOI: 10.11646/phytotaxa.726.4.5, URL: https://doi.org/10.11646/phytotaxa.726.4.5
