[Botany • 2025] Petalidium engoense (Acanthaceae) • A New Species from Angola and Namibia, with notes on phenotypic plasticity in the genus

 

Petalidium engoense

in Swanepoel, Becker Van Wyk, 2025. 

 DOI: doi.org/10.11646/phytotaxa.734.1.2

Abstract 

Petalidium engoense, first collected in May 2025, is here described as a new species. It is a range-restricted species, only known from the western edge of the escarpment zone (Great Escarpment of southern Africa), in the hilly area bordering the Engo Valley (northwestern Namibia), and to the north of Espinheira (southwestern Angola), in the Kaokoveld Centre of Endemism. It grows amongst boulders on arid hillsides, and along an ephemeral riverbed. Diagnostic characters for P. engoense include the pale greyish green appearance of the plants, ashy-grey to white fissured bark on older stems, vegetative parts with a dense white indumentum of very small stellate (stellulate) and dendritic trichomes appearing tomentose, semi-succulent leaves, burgundy flowers borne in short few-flowered dichasia with inflorescence axis becoming spiny with age, and narrowly ovate, attenuate to acute, prominently reticulate bracteoles. The flowers of P. engoense are distinctive in having all lobes coloured burgundy, and the anterior lobe with two yellow ensiform nectar guides. A comparison of key morphological features distinguishing P. engoense from P. namibense, its closest relative in appearance, is provided. Based on IUCN Red List criteria, a provisional conservation assessment of Critically Endangered (CR) is recommended for the new species. The paper also summarises current knowledge of phenotypic plasticity within Petalidium in response to environmental variation. This contribution forms part of ongoing taxonomic studies on the genus.

endemism, Engo River, Engo Valley, flora, Hartmann Valley, Iona National Park, Kaokoveld Centre of Endemism, Kunene Region, Namib Desert, Namibe Province, Ruellieae, taxonomy, variation, Eudicots

Petalidium engoense. Habit, vegetative and reproductive features.   
A. Woody stem with fissured bark at the base of a mature plant. B. Flowering shoot with semi-succulent leaves, which are covered in matted, greyish white indumentum and typically ca. folded upward along the midrib for their full length. C. Portion of a plant showing an open flower along with several old inflorescences; the inflorescence axes usually persist and have become spiny with age.

Photographs by W. Swanepoel.

Petalidium engoense. Morphology of inflorescences and flowers.
A. Distal part of a shoot showing both an open flower and a faded, brownish one, along with several bracteoles. B. Old inflorescences with dried, shriveled bracteoles and persistent axes that have become spiny (indicated by arrows). C, E. Frontal view of a flower showing uniformly coloured corolla lobes; the anterior lobe with two yellow, ensiform nectar guides. Visiting ants were feeding on scale insect larvae. D, G. Flower and bracteoles in lateral view. F. Flower with bracteoles, viewed from above. Photographs by W. Swanepoel.

Petalidium engoense. Habitat and habit.
A. Several plants growing among rocks along a seasonal drainage line in the Engo Valley, Kunene Region, Namibia. B. A mature plant (ca. 800 mm tall) displaying a densely branched structure with greyish green foliage. Photographs by W. Swanepoel.

Wessel SWANEPOEL, Rolf W. BECKER and Abraham E. VAN WYK. 2025. Petalidium engoense (Acanthaceae), A New Species from Angola and Namibia, with notes on phenotypic plasticity in the genus.  Phytotaxa. 734(1); 9-19. DOI: doi.org/10.11646/phytotaxa.734.1.2 [2025-12-16]

 

[Botany • 2025] Petalidium sebrabergense (Acanthaceae) • A New Species from Namibia

  

Petalidium sebrabergense  Swanepoel & A.E.van Wyk,

in Swanepoel et van Wyk, 2025. 

 DOI: doi.org/10.11646/phytotaxa.728.1.2

Photographs by W. Swanepoel.

Abstract

Petalidium sebrabergense, first collected in May 2024 and easily mistaken for P. cirrhiferum, is described here as a new species. It is a range-restricted species, only known from Namibia’s Zebra Mountains, within the Kaokoveld Centre of Endemism. It typically grows on plains, hillsides, and along ephemeral riverbeds and drainage lines, primarily in soils derived from anorthosite and gabbro of the Kunene Igneous Complex. Key distinguishing features for P. sebrabergense include the pale green appearance of the plants, vegetative parts with indumentum of dense, simple, multi-cellular stalked glandular trichomes, frequently interspersed with widely spaced eglandular simple and bifurcate trichomes, often with some leaves additionally bearing sparsely branched dendritic trichomes. The flowers are borne in racemose dichasia and are notable for having the corolla lobes lilac or mauve, with both sides concolorous. A comparison of key morphological features distinguishing P. sebrabergense from P. cirrhiferum, its closest look-alike, is provided. Brief comparisons are also made with P. huillense, P. subcrispum, and P. welwitschii, species with which it can be confused, particularly in herbarium specimens. Based on IUCN Red List criteria, a provisional conservation status of Critically Endangered (CR) is recommended for the new species.

anorthosite, endemism, Epupa, flora, Kaokoveld Centre of Endemism, Kunene Igneous Complex, Kunene Region, Kunene River, Ruellieae, Swartbooisdrif, taxonomy, ultramafic rocks, Zebra Mountains, Eudicots

Petalidium sebrabergense. 

Habit and leaf variation. 

A. Dwarf shrub ca. 400 mm high with relatively narrow leaves, growing among dark rocks of leucotroctolite. B. Dwarf shrub ca. 250 mm high with relatively broad leaves, growing in whitish anorthosite-derived soil.  

Habitat and habit. 

A. Dwarf shrubs in foreground with bright green foliage following recent rains; in open shrub and tree savanna of inter-mountain valley on whitish soil derived from anorthosite. B. Spreading dwarf shrubs in an ephemeral stream bed on whitish anorthosite-derived soil. 

Photographs by W. Swanepoel.

Petalidium sebrabergense. Morphology of flowers.
A. Shoot with relatively narrow leaves and flowers. B, C, D, E. Flowers in front view, each from a different plant to show variation. Corolla lobes are lilac or mauve (pale violet), both surfaces concolorous. F, G. Flower in side view; bracteoles abaxially with numerous simple multi-cellular stalked glandular trichomes up to 2 mm long (not or barely visible to the naked eye), but lacking dendritic trichomes.

Photographs by W. Swanepoel.

Petalidium sebrabergense Swanepoel & A.E.van Wyk, sp. nov. 

 Diagnosis:—A woody dwarf shrub up to 0.75 m tall, morphologically most similar to Petalidium cirrhiferum, differing by lacking dendritic trichomes on stems (vs. dendritic trichomes present); indumentum on leaves with trichomes sparsely to densely scattered (vs. appearing matted or floccose); leaf lamina lanceolate (sensu Lindley’s definition [Beentje 2016]), oblanceolate or elliptic (vs. lanceolate [sensu Lindley], ovate or narrowly ovate); bracteoles with indumentum abaxially lacking dendritic trichomes (vs. longstalked dendritic trichomes present); corolla lobes adaxially lilac or mauve (pale violet) (vs. heliotrope, magenta or purple-red [bright violet or red]).

Etymology:—The specific epithet refers to the Zebra Mountains (Fig. 1), known as Sebraberge in Afrikaans, located in northwestern Namibia, where Petalidium sebrabergense is exclusively found.

Wessel SWANEPOEL, Abraham E. VAN WYK. 2025. Petalidium sebrabergense (Acanthaceae), A New Species from Namibia. Phytotaxa. 728(1); 17-30. DOI: doi.org/10.11646/phytotaxa.728.1.2 [2025-11-11]

[Herpetology • 2025] Ptenopus adamanteus, P. circumsyrticus, P. sceletus, ... • Singing on Key: An integrative Taxonomic Revision of Barking Geckos (Squamata: Gekkonidae: Ptenopus) with six additional species and keys for morphology and advertisement calls

Ptenopus adamanteus 

 Ptenopus circumsyrticus

Ptenopus sceletus 

Becker, Alexander & Tolley, 2025

DOI: doi.org/10.3897/vz.75.e153514

 

Abstract

Barking geckos, Ptenopus Gray, 1866 are burrowing geckos that occur across the xeric regions of southern Africa. They possess unique vocal abilities, with males producing loud advertisement calls to attract females. The taxonomy of the genus has remained stable for six decades, with three recognised species: Ptenopus garrulus (Smith, 1849), P. kochi Haacke, 1964, and P. carpi Brain, 1962. Within P. garrulus, two subspecies have been recognised since 1935: the nominotypical form (P. g. garrulus) and P. g. maculatus Gray, 1866. A recent phylogenetic analysis of the genus found that it contains eight to ten putative species. We used an integrated taxonomic approach to delimit a total of nine species, including evidence from phylogenetics, ecology, calls, and morphology. Ptenopus g. maculatus is elevated to full species, thereby restricting the geographic range of P. garrulus sensu stricto to the greater Kalahari. Additionally, four new species are named which were previously included in ‘P. g. maculatus’: Ptenopus adamanteus sp. nov. from the southern Namib Desert, P. circumsyrticus sp. nov. from the central Namib Desert, P. kenkenses sp. nov. from the northern Nama Karoo, and P. australis sp. nov. from southern Nama Karoo. As a result, the range of P. maculatus sensu stricto is restricted to the central northern Namib Desert. Furthermore, one new species previously included in P. carpi is named P. sceletus sp. nov. from the Skeleton Coast (northern coastal Namib Desert), thereby restricting the range of P. carpi sensu stricto to a small strip of coastal Namib Desert between the Swakop and Kuiseb rivers. The Namib Desert is the centre of diversity for the genus Ptenopus, containing seven of the nine species including the oldest divergent lineages. Two species-level keys are provided: a morphological key and a unique bioacoustic key to the advertisement calls.

Keywords: Bioacoustics, mate selection, phylogeography, substrate specificity, systematics

Life colour variation and substrate matching in Ptenopus adamanteus sp. nov.
(A–D: northern populations; E–H: southern populations):
A NMNW R11390 (holotype), from Grosse Bucht, ||Karas Region, Namibia (–26.7338, 15.1041); B, C NMNW R11393 (paratype) from near locality A (–26.7208, 15.1026); D NMNW R11391 (allotype), from locality A;
E NMNW R11610 from 30 km E of Port Nolloth, Northern Cape Province, South Africa (–29.3049, 17.1836), not on native substrate; F NMNW R11611 from the same locality as E on native substrate; G NMNW R11598 from Oranjemund, ||Karas Region, Namibia (–28.5541, 16.4982); H unvouchered specimen from Port Nolloth (–29.2403, 16.8631), only 30 km W of locality of E/F.

Photos by Francois S. Becker.

Life colour variation in Ptenopus circumsyrticus sp. nov.:
 A NMNW R11394 (holotype) from Gobabeb, Erongo Region, Namibia (–23.5732, 15.0368); B FB2003 (unvouchered) from Keerwerder, NamibRand, Hardap Region, Namibia (–24.9818, 15.9338); C, D FB2080 from NE of Gobabeb (–23.3175, 15.5700); E unvouchered specimen from near locality of C; F NMNW R11355 (paratype) from near locality of B (–24.9495, 16.0397). Photos by Francois S. Becker.

Life colour variation and substrate matching in Ptenopus kenkenses sp. nov.:
 A, C NMNW R11388 (paratype) from Giant’s Playground, ||Karas Region, Namibia (–26.4538, 18.3097); B NMNW R11655 from S of Aus, ||Karas Region, Namibia (–26.7073, 16.2829); D NMNW R11648 from locality B; E FB454 from W of Aus (–26.5700, 15.8389); F FB456 from W of Aus (–26.6478, 16.2147). Photos by Francois S. Becker.

Life colour variation in Ptenopus sceletus sp. nov.:
 A NMNW R12103 (paratype) from N of Swakopmund, Erongo Region, Namibia (–22.6259, 14.5457); B NMNW R12101 (allotype) from locality A; C NMNW R11763 from Hoanib River, Kunene Region, Nambia (–19.3539, 13.1453); D NMNW R11754 from Henties Bay, Erongo Region, Namibia (–22.1584, 14.3086); E NMNW R12100 (holotype) and NMNW R011771 from the same locality as A, showing sexual dichromatism in gular patches of this species (male gular patch may be divided or undivided, while female only has slight shades of yellow on lateral edges); F NMNW R11771 from N of Swakop River near Swakopmund (–22.6652, 14.57619) and NMNW R11755 from N of the Omaruru River near Henties Bay (–21.7703, 14.5520), showing iris colour variation from silver (most common in the sourthern extreme of the range) to brown (more common further north). Photos by Francois S. Becker.

Ptenopus adamanteus sp. nov. 

Ptenopus australis sp. nov.

Ptenopus circumsyrticus sp. nov.

Ptenopus kenkenses sp. nov.

Ptenopus sceletus sp. nov.

Ptenopus maculatus (raised from a subspecies)

François S. Becker, Graham J. Alexander, Krystal A. Tolley. 2025. Singing on Key: An integrative Taxonomic Revision of Barking Geckos (Gekkonidae: Ptenopus) with six additional species and keys for morphology and advertisement calls. Vertebrate Zoology. 75: 277-323.  DOI: doi.org/10.3897/vz.75.e153514

[Botany • 2025] Petalidium saxatile (Acanthaceae) • A New Species from Namibia

Petalidium saxatile  Swanepoel, K.G.Dexter, E.Tripp & A.E.van Wyk,

in Swanepoel, Dexter, Adamo, Manzitto-Tripp et van Wyk. 2025.

 DOI: doi.org/10.11646/phytotaxa.716.3.1

 Abstract

Petalidium saxatile, hitherto confused with P. canescens, and the widespread P. setosum, is here described as a new species. It is a range-restricted species, only known from the vicinity of Palmwag and southwards to the Bergsig area with an outlier population to the south of Khorixas in the Kaokoveld Centre of Endemism, northwestern Namibia. It grows mainly among basaltic rocks of the Etendeka Group on arid hillsides and along ephemeral riverbeds and drainage lines. Diagnostic characters for P. saxatile include the pale green appearance of the plants, vegetative parts with a dense white indumentum of relatively short dendritic trichomes appearing matted on young leaves, flowers borne in compact dichasia, and long simple eglandular trichomes on the bracts visible to the naked eye. The flowers of P. saxatile are distinctive in having the corolla lobes inside (adaxially) distinctly bicolorous: the upper and lateral lobes are pink or brown-pink, while the anterior lobe is yellow. Additionally, all lobes are discolorous in being much paler outside (abaxially). Furthermore, analyses of genetic data across many nuclear loci, generated using a ddRADseq approach, show the species to be genetically distinct from P. canescens. A comparison of key morphological features distinguishing P. saxatile from P. canescens and P. setosum, is provided. Based on IUCN Red List criteria, a provisional conservation assessment of Endangered (EN) is recommended for the new species. It is suggested that the Etendeka Tableland, to which P. saxatile is largely confined, may serve as a local subcentre of plant endemism within the larger Kaokoveld Centre of Endemism, at least for species in the genus Petalidium.

Bergsig, endemism, Etendeka Group, flora, genetics, Kaokoveld Centre of Endemism, Khorixas, Kunene Region, Oberholzeria, Palmwag, RADseq, Ruellieae, taxonomy, Eudicots

Petalidium saxatile, morphology of flowers.
A, B. Newly opened and faded flowers. Anterior corolla lobe inside (adaxially) bright yellow and without nectar guides. C. Flower viewed from above, showing puberulous abaxial surface of posterior corolla lobes. D. Flowers viewed obliquely from above, all corolla lobes discolorous with the outside (abaxial) surfaces puberulous and notably paler in colour. The long white trichomes next to the flower on the right do not belong to the plant, but is a wind-blown feathery awn (arrowed) of a member of the grass genus Stipagrostis.

Photographs by W. Swanepoel.

Petalidium saxatile, habitat and habit.
Note relatively narrow leaves ca. folded upwards along the midrib (B & C). A. Several plants (some arrowed) growing in typical habitat among stones comprising Etendeka Group basalt on an arid hillside. B. Plant with pale grey-green foliage due to a more persistent whitish indumentum, and inflorescences. C. Plant in flower and with greenish foliage resulting from a sparser indumentum.

Photographs by W. Swanepoel.

Petalidium saxatile Swanepoel, K.G.Dexter, E.Tripp & A.E.van Wyk, sp. nov.

 Diagnosis:—A woody dwarf shrub up to 0.5 m tall, morphologically most similar to Petalidium canescens and P. setosum, differing by having indumentum on vegetative parts consisting of simple (weak and robust), bifurcate, stellate-dendritic, dendritic and stalked glandular trichomes, lacking sessile glands (vs. indumentum strigose with in addition widely spaced long, robust, simple trichomes [P. canescens]; long, robust, simple and stalked glandular trichomes, sessile glands present [P. setosum]); leaf lamina conduplicate (vs. flat or subconduplicate [P. canescens]; flat or irregularly curved, twisted, widely undulate, recurved or incurved towards margins [P. setosum]), usually narrower, up to 22 mm wide (vs. up to 100 mm [P. canescens (broad-leaved form)]; up to 50 mm [P. setosum]), with 3 or 4 principal lateral veins each side (vs. 4–6 [P. canescens]; 3–7 [P. setosum]); corolla expanded portion longer, 7.7–9.1 mm long (vs. ca. 7.5 mm [P. canescens]; ca. 3.4 mm [P. setosum]), anterior lobe inside (adaxially) bright yellow, lateral and upper lobes pink or brown-pink, darker towards bases (vs. all lobes similarly coloured: violet-red but anterior lobe darker [P. canescens]; purple, burgundy or carmine, anterior lobe sometimes yellow towards apex [P. setosum]), nectar guides absent (vs. present).

Wessel SWANEPOEL, Kyle G. DEXTER, Martino ADAMO, Erin A. MANZITTO-TRIPP, Abraham E. VAN WYK. 2025. Petalidium saxatile (Acanthaceae), A New Species from Namibia.  Phytotaxa. 716(3); 161-174. DOI: doi.org/10.11646/phytotaxa.716.3.1 [2025-09-03]

[Herpetology • 2025] Goggia sabula • A New Pygmy Gecko (Squamata: Gekkonidae: Goggia) from the arid Northern Cape Province of South Africa

  

Goggia sabula

Conradie, Hundermark, Kemp & Keates, 2025

DOI: doi.org/10.11646/zootaxa.5618.4.5  

 facebook.com: Courtney Hundermark

Abstract

The genus Goggia is composed of ten small bodied leaf-toed gecko species endemic to South Africa and adjacent Namibia. Using a combination of phylogenetic and morphological analyses we assessed the taxonomic status of an isolated rupicolous population discovered south of Klein Pella in the Northern Cape Province of South Africa. The newly collected material was recovered as a well supported clade by two independent phylogenetic algorithms (maximum likelihood and Bayesian inference), with little intraspecies structuring. While the particular interspecific relationships among closely related Goggia remain unresolved, the phylogenetic results suggest the novel material is related to G. rupicola, G. gemmula, G. incognita and G. matzikamaensis. This is supported by the similar ecologies (rupicolous lifestyle), geographies (arid western extent of South Africa) and morphologies (prominent dorsal chevrons and yellow-centred pale dorsal spots), which are shared among these closely related species. Despite their similarity, the novel population from Klein Pella remains geographically separate, differs from congeners by an uncorrected ND2 p-distance of 11.03–22.91%, and is morphologically diagnosable. Based on these findings we describe the Klein Pella population as a new species.

Reptilia, Gekkonidae, Namibia, arid, quartzite, cryptic species

Goggia sabula

Werner CONRADIE, Courtney HUNDERMARK, Luke KEMP and Chad KEATES. 2025. New Pygmy Gecko (Goggia: Gekkonidae) from the arid Northern Cape Province of South Africa.  Zootaxa. 5618(4); 552-570. DOI: doi.org/10.11646/zootaxa.5618.4.5 [2025-04-04] facebook.com/feverhunting/posts/10229231279309947

[Botany • 2025] Petalidium hoarusibense (Acanthaceae: Ruellieae) • A New Species from northwestern Namibia

Petalidium hoarusibense Swanepoel & A.E.van Wyk, 

in Swanepoel et van Wyk, 2025.  

 DOI: doi.org/10.11646/phytotaxa.681.1.1  

Abstract

Petalidium hoarusibense, hitherto misidentified as P. rossmannianum and P. ohopohense, is here described as a new species. It is a range-restricted species, only known from the area to the south and southeast of Okandjombo in the Kaokoveld Centre of Endemism, northwestern Namibia, where it grows on arid hillsides and along ephemeral riverbeds and drainage lines. Diagnostic characters for P. hoarusibense include the pale grey appearance of the plants, single or multi-stemmed from a thick rootstock, vegetative parts with a dense white indumentum of short dendritic, simple and bifurcate trichomes appearing matted, flowers borne in short, few-flowered dichasia, and bracteoles narrowly ovate or elliptic, deeply concave, appearing cobwebbed due to a mixture of loosely entangled long simple and dendritic trichomes. The flowers of P. hoarusibense are distinctive in having the lobes magenta with the anterior lobe sometimes slightly lighter shaded than the others and with two separate narrowly triangular yellow nectar guides. A comparison of key morphological features distinguishing P. hoarusibense from P. kaokoense, its closest relative in appearance, as well as from P. ohopohense, P. rossmannianum, P. sesfonteinense, and P. welwitschii, is provided. Based on IUCN Red List criteria, a provisional conservation assessment of Vulnerable (VU) is recommended for the new species.

endemism, flora, Kaokoveld, Kaokoveld Centre of Endemism, Kunene Region, Namib Desert, Ruellieae, Okandjombo, Hoarusib River, taxonomy, Eudicots

Petalidium hoarusibense. 
Morphology of leaves and flowers. A. Shoot with flower and leaves, the latter with dense, greyish white indumentum. B, C. Flower in front (B) and side (C) view; note bracteoles (some of spent flowers) with cobwebby indumentum. D, E, F, G. Flowers in front view, each from a different plant to show variation. Note all corolla lobes of a flower being ca. similarly coloured in various shades of magenta, or lateral and upper lobes slightly darker shaded than the anterior lobe, sometimes (as in D, E, G) with darker magenta or maroon triangular nectar guides; anterior lobe adaxially with two narrowly triangular yellow nectar guides.

Photographs by W. Swanepoel.

Petalidium hoarusibense.
Habitat and habit. A. Mature plant ca. 800 mm high (greyish shrub in foreground), growing among dark grey sedimentary rocks of the Swakop Group along the banks of the Hoarusib River near Okandjombo, Namibia. B. Base of plant showing several branches arising from the main stem just above ground level, each covered with rough, fissured, greyish white bark.

Photographs by W. Swanepoel.

Petalidium hoarusibense Swanepoel & A.E.van Wyk, sp. nov.  

Diagnosis:—A woody dwarf shrub up to 1.2 m tall, morphologically most similar to Petalidium kaokoense, from which it differs in having indumentum on the bracteoles cobwebbed, consisting of a mixture of loosely entangled simple and dendritic trichomes up to 2.5 mm long, with in addition scattered short-stalked glandular trichomes (vs. matted/compact, stellate and dendritic, shorter, up to 0.5 mm long, lacking glandular trichomes); corolla glabrous outside (vs. exposed part strigose); nectar guides on anterior lobe narrowly triangular, separate (vs. linear-oblong, confluent or nearly so).

Etymology:—The specific epithet refers to the Hoarusib River and its catchment to which Petalidium hoarusibense is endemic.

Wessel SWANEPOEL and Abrahan E. van WYK. 2025. Petalidium hoarusibense (Acanthaceae), A New Species from Namibia.  Phytotaxa. 681(1); 1-10. DOI: doi.org/10.11646/phytotaxa.681.1.1  

 

[Botany • 2025] Stenandriopsis darainensis (Acanthaceae) • A New Species and a new combination in Stenandriopsis from Madagascar

 

Stenandriopsis darainensis I.Darbysh. & Callm., 

in Darbyshire, Callmander et Randriamamonjy, 2025.  

DOI: doi.org/10.1007/s12225-024-10246-9

 

Summary

A new species of the palaeotropical genus Stenandriopsis S.Moore (Acanthaceae) is described from Daraina region (Loky-Manambato) in northeastern Madagascar, and named S. darainensis I.Darbysh. & Callm. It is compared to the most similar species morphologically, S. boivinii (S.Moore) Benoist, and notes on its habitat preferences and conservation status (extinction risk) are provided — it is assessed using IUCN criteria as Vulnerable [VU D2]. In addition, Stenandriopsis leptostachys Benoist var. longifolia Benoist from southern Madagascar is re-elevated to full species status and a new combination in Stenandriopsis is made for this taxon, Stenandriopsis longifolia (Benoist) I.Darbysh. & Callm.

Key Words: Acantheae, endemic, IUCN Red List assessment, novelty, taxonomy

Stenandriopsis darainensis.
 A habit; B indumentum of young stems; C bract, abaxial surface; D apex of bract, abaxial surface, showing eglandular indumentum (shown on the margin only) and positions of scattered glandular hairs; E bracteoles, inner (left) and outer (right) surfaces; F dissected calyx; G corolla, face view; H indumentum of corolla tube, with enlargement of one eglandular and one glandular hair; J dissection of corolla tube showing (left to right) style and stigma, two shorter anthers and two longer anthers (note that the adaxial staminode is hidden behind the two short anthers).

Drawn from P. Ranirison PR 731: A Geneva herbarium; B – J Kew Herbarium, 

except G from photos. drawn by Andrew Brown.

Stenandriopsis darainensis. Flowers, photographed at fôret d’Antsaharaingy, 21 April 2004, collected as P. Ranirison PR 731.

 photo: P. Ranirison.

Iain Darbyshire, Martin W. Callmander and Nomentsoa J. E. Randriamamonjy. 2025. A New Species and a new combination in Stenandriopsis (Acanthaceae) from Madagascar.  Kew Bulletin. DOI: doi.org/10.1007/s12225-024-10246-9

[Botany • 2024] Petalidium namibense (Acanthaceae: Ruellieae) • A New Species from Namibia

  Petalidium namibense Swanepoel & A.E.van Wyk,

in Swanepoel et van Wyk. 2024.  

DOI: doi.org/10.11646/phytotaxa.671.2.2 

 

Abstract

Petalidium namibense, hitherto confused with P. englerianum, P. rossmannianum, and the widespread P. variabile, is here described as a new species. It is a range-restricted species, only known from the area to the southwest, west and northwest of Puros in the Kaokoveld Centre of Endemism, northwestern Namibia, where it grows at the base of rocky outcrops, on arid hillsides, and along ephemeral riverbeds and drainage lines. Diagnostic characters for P. namibense include the pale grey appearance of the plants, corky bark on older stems, vegetative parts with a dense white indumentum of relative long dendritic trichomes appearing lanate, flowers borne in short few-flowered dichasia, and bracteoles narrowly ovate. The flowers of P. namibense are distinctive in having the two upper corolla lobes discolorous, abaxially light brown, adaxially vermillion, without nectar guides, and connate towards the base for 25–40% of their length. The anterior lobe is adaxially magenta with two relative long, narrowly triangular yellow nectar guides. The two lateral lobes are adaxially vermillion, or distally magenta, grading to vermillion towards the throat, and lack conspicuous nectar guides. A comparison of key morphological features distinguishing P. namibense from P. sesfonteinense, its closest relative in appearance, as well as from P. englerianum, P. rossmannianum, and P. variabile, is provided. Based on IUCN Red List criteria, a provisional conservation assessment of Vulnerable (VU) is recommended for the new species. 

endemism, flora, Kaokoveld Centre of Endemism, Kunene Region, Namib Desert, Ruellieae, Puros, taxonomy, Eudicots

Petalidium namibense, habitat and habit. 

A. Mature plant (ca. 0.5 m high) with greyish appearance, growing among rocks. 

B. Multiple stems (thickest ca. 80 mm in diam.) from base of a relatively old plant, each covered with thick corky bark.  

Petalidium namibense, habitat and habit. 

A. Several plants (dark grey dwarf shrubs) growing in the bed of an ephemeral drainage line. 

B. Ancient windswept plant sprouting from persistent woody stems with corky bark. 

Photographs by W. Swanepoel.

 Petalidium namibense, morphology of leaves and flowers.
 A. Flower, reduced shoots, and congested leaves; leaves with dense greyish indumentum. B. Flower in the process of fading as indicated by its pale colours. C. Newly opened flower with bracteoles in oblique lateral view; note brownish abaxial colour of posterior corolla lobes. D. Flower in front view. E. Flower with bracteoles in lateral view. F. Flower in dorsal view.

 Photographs: W. Swanepoel.

Petalidium namibense Swanepoel & A.E.van Wyk, sp. nov.  

Diagnosis:—A woody dwarf shrub up to 1 m tall, morphologically most similar to Petalidium sesfonteinense, differing by having the leaf lamina ovate, elliptic, suborbicular or orbicular (vs. ovate, elliptic or oblanceolate); bracteoles with trichomes dendritic, interspersed with glandular ones (vs. trichomes glandular with in addition appressed simple ones towards base); corolla shorter, 15.0–17.5 mm (vs. 20–24 mm long), upper lobes rectangular, smaller, 4.9–5.2 × 2.9–3.2 mm (vs. obovate, 5.8–8.2 × 3.5–4.3 mm), upper and lateral lobes differently coloured than anterior lobe with nectar guides absent or inconspicuous (vs. all lobes similarly coloured, nectar guides on upper and lateral lobes conspicuous).

Etymology:—The specific epithet refers to the Namib Desert to which Petalidium namibense is endemic. The Namib Desert in its broadest definition, stretches along the Atlantic Ocean from Saõ Nicolau (Bentiaba) in Angola through Namibia to the Olifants River in South Africa (Seely 2004, Goudie & Viles 2015).

Petalidium sesfonteinense, morphology of leaves and flowers.
A. Flowers, shoots, and leaves; greyish leaves are still densely covered in trichomes; green leaves almost glabrous. B–E. Flowers in front view showing variation in corolla colour and lobe margins, with two yellow nectar guides.

Photographs: W. Swanepoel. 

Republished from Swanepoel & Manzitto-Tripp (2022).

Wessel Swanepoel and Abraham E. van Wyk. 2024. Petalidium namibense (Acanthaceae), A New Species from Namibia.  Phytotaxa. 671(2); 128-138. DOI: doi.org/10.11646/phytotaxa.671.2.2 

[Paleontology • 2024] Gaiasia jennyae • Giant stem Tetrapod was Apex Predator in Gondwanan late Palaeozoic Ice Age

  

Gaiasia jennyae

Marsicano, Pardo, Smith, Mancuso, Gaetano & Mocke, 2024

DOI: 10.1038/s41586-024-07572-0

Abstract

Current hypotheses of early tetrapod evolution posit close ecological and biogeographic ties to the extensive coal-producing wetlands of the Carboniferous palaeoequator with rapid replacement of archaic tetrapod groups by relatives of modern amniotes and lissamphibians in the late Carboniferous (about 307 million years ago). These hypotheses draw on a tetrapod fossil record that is almost entirely restricted to palaeoequatorial Pangea (Laurussia). Here we describe a new giant stem tetrapod, Gaiasia jennyae, from high-palaeolatitude (about 55° S) early Permian-aged (about 280 million years ago) deposits in Namibia that challenges this scenario. Gaiasia is represented by several large, semi-articulated skeletons characterized by a weakly ossified skull with a loosely articulated palate dominated by a broad diamond-shaped parasphenoid, a posteriorly projecting occiput, and enlarged, interlocking dentary and coronoid fangs. Phylogenetic analysis resolves Gaiasia within the tetrapod stem group as the sister taxon of the Carboniferous Colosteidae from Euramerica. Gaiasia is larger than all previously described digited stem tetrapods and provides evidence that continental tetrapods were well established in the cold-temperate latitudes of Gondwana during the final phases of the Carboniferous–Permian deglaciation. This points to a more global distribution of continental tetrapods during the Carboniferous–Permian transition and indicates that previous hypotheses of global tetrapod faunal turnover and dispersal at this time must be reconsidered.

 

Claudia A. Marsicano, Jason D. Pardo, Roger M. H. Smith, Adriana C. Mancuso, Leandro C. Gaetano  and Helke Mocke. 2024. Giant stem Tetrapod was Apex Predator in Gondwanan late Palaeozoic ice age. Nature.  DOI: 10.1038/s41586-024-07572-0

[Entomology • 2018] Microphontes gaiophanes, M. kryphios, etc. • Taxonomic Revision of the Assassin-fly Genus Microphontes Londt, 1994 (Diptera, Asilidae)

Microphontes gaiophanes

Markee & Dikow, 2018

DOI: 10.3897/afrinvertebr.59.30684 

twitter.com/TDikow

Abstract

The genus Microphontes Londt, 1994 (Diptera: Asilidae: Brachyrhopalinae) is revised. Currently, three species are known from Namibia and western South Africa, i.e. Microphontes megoura Londt, 1994 from north-western South Africa, Microphontes safra Londt, 1994 from Namibia and Microphontes whittingtoni Londt, 1994 from western South Africa. Four new species, Microphontes ericfisheri sp. n. from the Little Karoo of South Africa, Microphontes gaiophanes sp. n. from the Namib desert of Namibia and Microphontes jasonlondti sp. n. and Microphontes kryphios sp. n. from western South Africa, are described. Distribution, occurrence in biodiversity hotspots sensu Conservation International and seasonal incidence are discussed. Descriptions/redescriptions, photographs and identification keys are provided and made openly accessible in data repositories to support future studies of the included taxa. An unusual flight pattern of male Microphontes gaiophanes sp. n. is discussed. A unique morphological feature on tergite 8 of Microphontes females, termed postero-paramedian T8 pores, is described, illustrated and discussed.

Keywords: Assassin fly, robber fly, cybertaxonomy, open-access, male flight behaviour, female postero-paramedian T8 pores

 

Microphontes gaiophanes sp. n. (♂ Holotype, USNMENT01115122):
6 dorsal (Morphbank #861782) 7 lateral (#86178) 8 head anterior (#861787). Scale bar: 5 mm (6–7), 1 mm (8).

Microphontes ericfisheri sp. n.

Etymology: The species is named after Eric M. Fisher who is one of the most knowledgeable Nearctic and Neotropical Asilidae taxonomists, present and past, to recognise his contributions to the study of assassin flies. This species was unveiled at the 9th International Congress of Dipterology (25–30 November 2018) in Windhoek, Namibia during the Asilidae symposium organised to honour a contemporary colleague, Jason Londt and entitled, “Taxonomy and phylogeny of Asilidae – honouring 40 years of Afrotropical research by Jason Londt” on 27 November 2018.

Distribution, biodiversity hotspots, phenology and biology: Known only from the type locality in the Little Karoo of South Africa (Fig. 71). A rarely collected species known only from a single specimen and collecting event in 2015 (Table 1). The species is endemic to the Succulent Karoo biodiversity hotspot. Adult flies are active in mid summer in a winter rainfall region (Table 2). Nothing is known of the biology.

 Photographs of Microphontes gaiophanes sp. n. in nature on sand dune as in Figs 1–2:
9 ♂ resting on sand (note that pro-, mes- and metathoracic legs are held sideways and up so that tarsi do not touch sand, Morphbank #861774)

Photograph by T. Dikow.

  Photographs of Microphontes gaiophanes sp. n. in nature on sand dune as in Figs 1–2:
 10 ♀ resting on dry vegetation just above ground (#861777).

Photograph by T. Dikow.

Microphontes gaiophanes sp. n.

Etymology: Greek gaiophanes = earth-coloured. Refers to the beautiful earth tone colouration of this species.

Diagnosis: The species is distinguished from congeners by the more or less square abdominal tergites, the short macrosetose dorsal anepisternum, the extensively macrosetose ante- and postpronotum, the overall brown colouration and the grey pubescent female abdominal tergite 8.

 Habitat photographs: 1–2 sparsely vegetated sand dune on the eastern edge of the Namib Sand Sea N of Solitaire, Namibia (23°34'22"S, 015°48'37"E) where Microphontes gaiophanes sp. n. was collected 3–4 slope of Elim Dune with Stipagostris sp. (Poaceae) on the eastern edge of the Namib Sand Sea W of Sesriem, Namibia (24°27'28"S, 015°46'37"E) where M. safra was collected. Photographs by T. Dikow.

Microphontes jasonlondti sp. n.

Etymology: The species is named after Jason G.H. Londt who is without doubt the most knowledgeable Afrotropical Asilidae taxonomist, present and past, to recognise his contributions to the study of assassin flies and who also collected the type series. This species was unveiled at the 9th International Congress of Dipterology (25–30 November 2018) in Windhoek, Namibia during the Asilidae symposium organised in his honour entitled, “Taxonomy and phylogeny of Asilidae – honouring 40 years of Afrotropical research by Jason Londt” on 27 November 2018.

Diagnosis: The species is distinguished from congeners by the only slightly transversely rectangular abdominal tergites, the general brown colouration and a long gonocoxite extending beyond midpoint of the epandrium (in lateral view) in the male terminalia.

Microphontes kryphios sp. n.

  

Etymology: Greek kryphios = hidden, secret. Refers to the fact that this species was hidden amongst the type series of M. whittingtoni.

Diagnosis: The species is distinguished from congeners by the small size with a wing length of 3–4 mm, distinctly wider than long and transversely rectangular abdominal tergites, partly macrosetose postpronotal lobes, setose dorsal and posterior anepisternum and features of the male terminalia such as the long postero-median projection on the hypandrium and shape of the gonostyli.

Seasonal incidence: 

Species of Microphontes have been collected in the Southern Hemisphere spring to summer (Table 2). M. ericfisheri sp. n. is restricted in imago flight activity to summer (December), M. gaiophanes sp. n. to spring (September), M. jasonlondti sp. n., M. kryphios sp. n., M. megoura and M. whittingtoni to early summer (November) and M. safra to late summer (February).

Biodiversity hotspots: 

Two species, M. ericfisheri sp. n. and M. whittingtoni, occur in and are endemic to the Succulent Karoo biodiversity hotspot sensu Conservation International (Fig. 72). M. jasonlondti sp. n. and M. kryphios sp. n. occur within the same hotspot, but have also been collected outside of it in the adjacent Nama Karoo biome. M. megoura occurs in and is endemic to the Cape Floristic Region biodiversity hotspot (Fig. 72). The other two species, M. gaiophanes sp. n. and M. safra, lie well outside any hotspot in the Namib Desert (Fig. 72). The unidentified specimen from Willie Nel Farm (32°10'47"S, 018°53'29"E) occurs within the Cape Floristic Region hotspot (Fig. 71).

 Amanda Markee and Torsten Dikow. 2018. Taxonomic Revision of the Assassin-fly Genus Microphontes Londt, 1994 (Insecta, Diptera, Asilidae).  African Invertebrates. 59(2): 195-237.  DOI: 10.3897/afrinvertebr.59.30684

 twitter.com/TDikow/status/1068790226603188224