[Botany • 2025] Boswellia oropedionis (Burseraceae) • A New frankincense tree Species from Socotra, and notes on B. ameero and B. bullata

Boswellia oropedionis Thulin & M.H.Weber,

in Thulin, Weber et Mubarak, 2025.

DOI: doi.org/10.1002/njb.04801

Abstract The new species Boswellia oropedionis Thulin and M.H.Weber is described, illustrated by photographs and mapped. This tree is only known from a small population growing on level limestone on the Qatariyah plateau in southern Socotra and is the twelfth endemic species of Boswellia from the Socotra archipelago. It differs from B. dioscoridis Thulin by having 7–9-foliolate leaves with pubescent nerves on the upper side, and by having larger flowers and fruits. Boswellia ameero Balf.f. is shown to have broadly winged pyrenes, an unusual feature in the genus and unique among the species on Socotra. Two new localities are reported for B. bullata Thulin, which is shown to have mostly narrowly winged pyrenes.

Keywords: endemic species, taxonomy, Yemen

Boswellia oropedionis sp. nov., from type locality, 21 May 2024.
(A) tree, showing expanded trunk-base, (B) upper branches of tree, showing leaves, inflorescences and young fruits. Photographs by Michael Weber.

Boswellia oropedionis Thulin and M.H.Weber sp. nov.

A species differing from Boswellia dioscoridis Thulin by having 7–9-foliolate leaves pubescent with crisped hairs along the nerves above (versus leaves mostly 11–17-foliolate and entirely glabrous above), petals 7.0 × 3.5 mm (versus 5.0 × 2.5–3.0 mm), stamens with filaments 3 mm (versus 1.5–2.0 mm) long and anthers 2.8 mm (versus 1.2–1.8 mm) long, disk 5.5 mm (versus 3.0–3.5 mm) in diameter, fruits 12–15 × 10–12 mm (versus 7–12 × 4–9 mm) and pyrenes 8.0–10.0 × 4.5–5.5 mm (versus 5.5–7.5 × 2.0–4.0 mm).

Etymology: The epithet ‘oropedionis' (from Greek for ‘of the plateau') refers to the habitat of the species.

Mats Thulin, Michael H. Weber and Sami Ali Mohammed Mubarak. 2025. Boswellia oropedionis (Burseraceae) sp. nov., a frankincense tree from Socotra, and notes on B. ameero and B. bullata. Nordic Journal of Botany. DOI: doi.org/10.1002/njb.04801 [08 May 2025]

[Botany • 2025] Boswellia hesperia (Burseraceae) • A New Species from Socotra

Boswellia hesperia Thulin, M.H.Weber & Rzepecky, 

in Thulin, Weber, Mubarak et Rzepecky, 2025.

 DOI: doi.org/10.1111/njb.04728

Researchgate.net/publication/389133907

Abstract

The new species Boswellia hesperia Thulin, M.H.Weber and Rzepecky is described, illustrated and mapped. It is a dwarf tree, restricted to westernmost Socotra (Yemen), growing on limestone rocks, in which the usually prostrate stems tend to fill out holes and crevices. It differs from B. nana Hepper, another dwarf tree endemic to Socotra but restricted to the easternmost parts of the island, by having leaves densely pubescent with whitish hairs beneath and by its smaller flowers and fruits.

Keywords: dwarf tree, frankincense, taxonomy, Yemen

Boswellia hesperia sp. nov. from mountain ridge above Neet, 5–6 km from the coast, Socotra, 18 May 2021.
(A) plant filling out crevice in limestone rock, leafless, showing reddish white flowers and fruits, (B) leafless plant with flowers and fruits. Photographs by Alain Rzepecky.

Boswellia hesperia sp. nov. from the type locality above Neet in Socotra, 30 Apr. 2023.
(A) plant showing upper surfaces of leaves and 5- or 4-merous flowers with reddish white petals, (B) flowers, showing calyx and outside of petals, and undersides of leaves with dense indumentum of crisped whitish hairs, (C) plant showing 3-locular fruit. Photographs by Michael Weber.

Boswellia hesperia sp. nov. from above Neet, Socotra, 17 May 2024.
 (A) plant showing flower and 4-locular fruits, (B) plant showing 4-merous flowers with cream or whitish petals, (C) plant showing 3-merous flower with whitish petals. Photographs by Michael Weber.

Boswellia hesperia sp. nov.
(A) flower, top view, (B) detail of petal margin, (C) flower, side view, (D) fruit, (E) pyrene, ventral view, (F) pyrene, dorsal view, (G) leaf from short shoot, upper side, (H) leaf from short shoot, lower side, (I) leaf from long shoot, upper side, (J) portion of plant with leaves, (K) long shoot, (L) seedling, showing lobed cotyledons. Drawing by Alain Rzepecky.

Boswellia hesperia sp. nov., plant filling out hole in limestone rock, showing leaves and reddish flowers; above Neet, Socotra, 31 Oct. 2007. Photograph by Lisa Banfield.

Boswellia hesperia Thulin, M.H.Weber and Rzepecky, sp. nov.  

A dwarf tree similar to Boswellia nana Hepper, but differing by having leaves densely pubescent with ± crisped whitish hairs (versus glabrous or subglabrous) beneath, smaller flowers with petals 3–4 mm (versus 4.5–5.5 mm) long and smaller fruits (5–7 mm versus ca 10 mm long).

Etymology: The epithet ‘hesperia' (Latin, western) refers to the distribution of this species that is restricted to the westernmost part of Socotra.

Mats Thulin, Michael Weber, Sami Ali Mohammed Mubarak and Alain Rzepecky. 2025. Boswellia hesperia sp. nov. (Burseraceae) from Socotra. Nordic Journal of Botany. DOI: doi.org/10.1111/njb.04728

 Researchgate.net/publication/389133907_Boswellia_hesperia_sp_nov_from_Socotra

[Botany • 2022] Commiphora omundomba (Burseraceae) • A New Species from the Kaokoveld Centre of Endemism, Angola and Namibia

Commiphora omundomba Swanepoel & Weeks,

in Swanepoel, Weeks & van Wyk, 2022. 

Iona corkwood | ionakanniedood  || DOI: 10.11646/phytotaxa.543.4.1

  twitter.com/pterygote

Photographs by W. Swanepoel.

Abstract

Commiphora omundomba, described here as a new species, is known only from the Kaokoveld Centre of Endemism, a biogeographical region in southwestern Angola and Northwestern Namibia. It has hitherto been confused with C. dinteri from west-central Namibia, but both morphological and molecular evidence support a distinction between the two species. Phylogenetic analysis of DNA sequence data indicates that C. omundomba shares most-recent common ancestry with C. buruxa, a species limited to the Gariep Centre of Endemism in southwestern Namibia. Diagnostic morphological characters for C. omundomba include the white, viscous exudate, smooth bark and glabrous, trifoliolate leaves. Photographs of the plant and a distribution map are provided. The new species is mainly confined to near the Atlantic coast of the northern Namib Desert, and is widespread and locally common between Santa Maria in Angola and Puros in Namibia.

Keywords: Commiphora buruxa, Commiphora dinteri, Iona National Park, Kaokoveld Centre of Endemism, Namib Desert, phylogeny, Sapindales, systematics, taxonomy

Commiphora omundomba, flower (A, B), fruit (C–E) and stone (F–H) morphology.
A & B. Male flower with three petals and three stamens, viewed from the side (A) and from above (B). C–E. Fruit in posterior (C), anterior (D), and side (E) view. F–H. Stone with pseudo-aril, view of fertile locule (F), sterile locule (G), and as seen from the side (H).

Scale bar = 2 mm. Photographs by W. Swanepoel.

Commiphora omundomba, variation in leaf morphology (A, B) and trunk with thicker branches showing smooth, non-peeling bark (C).
A. Leaves with lamina entire. B. Leaves with lamina crenate to crenate-serrate. C. Plant with short trunk (partly hollowed out), about 200 mm in diameter; note some branches with prominent almost parallel longitudinal ridges.

Scale bar = 5 mm. Photographs by W. Swanepoel.

Commiphora omundomba, habitat and habit.
A. Ascending, leafless shrub-like trees in foreground, ca. 70 km from the Atlantic Coast.
B. Prostrate shrub on top of sandstone cliffs along the coast.

Photographs by W. Swanepoel.

Commiphora omundomba Swanepoel & Weeks, sp. nov. 

Diagnosis:— Differs from C. dinteri in the terminal leaflets being oblanceolate or narrowly obovate (vs. obovate); lateral leaflets oblanceolate, narrowly obovate, obovate, elliptic, oblong, or suborbicular (vs. broadly elliptic or suborbicular); ratio length of terminal leaflets to width being 1.9–3.2:1 (vs.1–2:1); ratio length of terminal leaflets to lateral leaflets being 1.1–1.4:1 (vs. 1.5–2.9:1); leaflet margins often entire (vs. always toothed); calyx eglandular (vs. glandular); number of calyx lobes and petals 3 or rarely 4 (vs. 4); number of disc lobes 3 or rarely 4 (vs. 4); in male flowers distal part of disc lobes adnate to hypanthium, obscurely bifid at apex (vs. distal part not adnate to hypanthium, distinctly bifid at apex); pseudo-aril with commissural arms shorter, extending 25–65% the length of putamen (vs. longer, 75–95%).

Etymology and common names:—The specific epithet is the local Ovahimba vernacular name (a dialect of Otjiherero) for the new species. As vernacular names in English and Afrikaans we propose Iona corkwood and ionakanniedood.

Wessel Swanepoel, Andrea Weeks and Abraham E. van Wyk. 2022. Commiphora omundomba (Burseraceae), A New Species from Angola and Namibia. Phytotaxa. 543(4); 207-218. DOI: 10.11646/phytotaxa.543.4.1 

  twitter.com/pterygote/status/1516776706652090368

    

[Botany • 2019] Boswellia occulta (Burseraceae) • A New Species of Frankincense Tree from Somalia (Somaliland)

Boswellia occulta Thulin, DeCarlo & S.P.Johnson

in Thulin, DeCarlo & Johnson, 2019.

  DOI: 10.11646/phytotaxa.394.3.3

Abstract

The new species Boswellia occulta is described from a small area in the Ceel Afweyn District of Somaliland (northwestern Somalia), where it is locally of considerable socio-economic importance. Although used for frankincense production by many generations of local harvesters, it has been unknown to science until now. Apart from the recently collected type material, it is also known from a sterile and hitherto misunderstood collection made in 1945. The simple-leaved Boswellia occulta is morphologically compared with B. sacra and B. frereana, the two major frankincense-producing species in the region, both with imparipinnate leaves, and it appears to be most closely related to B. sacra. The new species is the only simple-leaved species of Boswellia known outside Socotra.

Keywords: Boswellia, frankincense, taxonomy, Somaliland, Eudicots

FIGURE 1. Holotype of Boswellia occulta, with field label and still unmounted.

 Photograph: Stephen P. Johnson.

FIGURE 2. Boswellia occulta, from the type locality
A. Tree, in leaf; B. Tree, showing swollen disk-shaped base when growing on rock; C. Branches, showing foliage; D. Trunk with incisions, showing resin oozing out.

Photographs: Ahmed Mohamed Dhunkaal.

Boswellia occulta Thulin, DeCarlo & S.P.Johnson sp. nov.

Boswellia occulta differs from B. frereana by its flowers with white (vs reddish or greenish red) petals and tubular (vs flattened) disk, and fruits with 4–5 [vs (5–)6(–8)] locules; and from B. sacra by its glabrous (vs ± densely pubescent) leaves with mostly strongly undulate-sinuate (vs crenate to subentire) margins, and unwinged pyrenes (vs pyrenes often more or less surrounded by a persistent wing); and from both B. frereana and B. sacra by its simple (vs imparipinnate) leaves.

...

Distribution and habitat:— Boswellia occulta is only known from a small area in northwestern Somalia (Somaliland) (Fig. 4), where it is locally common and the dominant tree on west-facing arid hillsides on limestone at 400–500 m elevation. The tree usually grows directly on limestone cliffs and boulders, and then has a more or less swollen disk-shaped base of the trunk (Fig. 2B). More detailed studies of the extent of the range of the species and the numbers and densities of the trees and their regeneration are planned in the near future.

Etymology:— The epithet “occulta” (from Latin “occultus”, hidden) refers to the history of this species that, although used for frankincense production by many generations of local harvesters, has been unknown to science until now.

Vernacular name and uses:— Mohor madow (Somali, fide Glover & Gilliland 719 and Ahmed Mohamed Dhunkaal s.n.); this is the vernacular name generally used also for B. sacra in Somalia. However, the harvesters in the B. occulta area distinguish between B. occulta (“mohor madow”) and B. sacra (“mohor cad”, “mohor dadbeed” or “mohor lab”). Frankincense produced from B. occulta (Fig. 2D) has unique properties (DeCarlo, unpublished research data) and is important in the local economy

Mats Thulin, Anjanette DeCarlo and Stephen P. Johnson. 2019. Boswellia occulta (Burseraceae), A New Species of Frankincense Tree from Somalia (Somaliland). Phytotaxa. 394(3); 219–224.   DOI: 10.11646/phytotaxa.394.3.3