|Ocimum sebrabergensis Swanepoel & van Jaarsv.|
in Swanepoel & van Jaarsveld, 2019
Ocimum sebrabergensis, here described as new species, has a restricted range and is only known from the Zebra Mountains within the Kaokoveld Centre of Endemism, northwestern Namibia. These shrubs grow on clayey soil among greyish black rocks of anorthosite. Diagnostic characters for O. sebrabergensis include the mauve-coloured corolla with four orbicular lobes on the posterior lip and the calyx which has the lateral lobes of the anterior lip asymmetric lanceolate. Ocimum sebrabergensis is placed in Ocimum subg. Ocimum sect. Hiantia subsect. Hiantia ser. Serpyllifolium. A comparison of some of the more prominent morphological features to differentiate between O. sebrabergensis and its possible nearest relatives, O. burchellianum and O. fimbriatum, are provided. Based on IUCN Red List categories and criteria, a conservation assessment of Vulnerable (VU D1) is recommended for the new species.
Keywords: Kunene Region, General, Eudicots
|FIGURE 1. Ocimum sebrabergensis. Plant in natural habitat among greyish black boulders of anorthosite, growing as a shrub about 1.8 m tall. Photograph: W. Swanepoel.|
|FIGURE 2. Ocimum sebrabergensis. Leaves, photographed from lower north-facing slope of Ombuku peak, along stream. Photograph: E.J. van Jaarsveld.|
|FIGURE 4. Ocimum sebrabergensis. Flowers. Photograph: W. Swanepoel.|
|FIGURE 3. Ocimum sebrabergensis. Inflorescences. Photograph: W. Swanepoel.|
Ocimum sebrabergensis Swanepoel & van Jaarsv., sp. nov.
Ocimum subg. Ocimum
sect. Hiantia subsect. Hiantia
A woody shrub 1–2 m tall, related to Ocimum burchellianum and O. fimbriatum, differing from O. burchellianum by being severalstemmed from base (vs. soft shrub, single-stemmed from base), leaves petiolate, lamina subcordate or ovate to narrowly ovate (vs. subsessile, lamina subspatulate to oblanceolate); from O. fimbriatum by the shrubby habit (vs. annual stems arising from a thick woody rootstock).
Etymology:— The specific epithet refers to the “Sebraberge” (Afrikaans for “Zebra Mountains”) in the Kaokoveld of northwestern Namibia, the type locality of the new species.
Notes:— Ocimum sebrabergensis differs from O. burchellianum and O. fimbriatum in habit, leaf, and flower characters. Apart from the differences in habit and morphological characters, the distribution of the three taxa differs with O. sebrabergensis being confined to the Kaokoveld Centre of Endemism in Namibia and O. burchellianum to the Eastern Cape Province of South Africa, whilst O. fimbriatum has a wide distribution in tropical Africa. Some of the more prominent morphological features to differentiate amongst O. sebrabergensis, O. burchellianum and O. fimbriatum are supplied in Table 1. Diagnostic features for O. sebrabergensis were determined through examination of fresh material and for O. burchellianum, and O. fimbriatum from the literature (Codd 1985, Paton 1995, Van Wyk & Malan 1997, Paton et al. 1999, 2013).
Wessel Swanepoel and Ernst J. van Jaarsveld. 2019. Ocimum sebrabergensis (Lamiaceae), A New Species from Namibia. Phytotaxa. 405(4); 203–209. DOI: 10.11646/phytotaxa.405.4.4