Othonna pteronioides Harv.

Magoswana, S. L., Boatwright, J. S., Magee, A. R. & Manning, J. C., 2022, A taxonomic revision of the Othonna coronopifolia L. group (Asteraceae: Senecioneae: Othonninae), South African Journal of Botany 149, pp. 604-616 : 606-609

3. Othonna pteronioides Harv. in Fl. Cap. 3: 332 (1865) .

Type: South Africa, ‘ Cape’,?date, Drege ( S, holo., not seen) . [Note: due to ongoing renovations to the Swedish Museum of Natural History (S) we could not view the type material).

Shrubs to 1 m, stems woody, simple or branched in upper half, branches divaricate, ending in a thorn, striate, deep red when young becoming pale grey with age, leaf axils cobwebbed, sometimes glabrous. Leaves alternate, often in axillary tufts or fascicled on short-shoots, sessile, blade oblanceolate to elliptic, leathery to succulent and elliptic in section, 3 - 10 £ 2 - 4 mm, entire. In fl orescence of mostly solitary capitula, terminal on stems or on short-shoots; peduncles 10 - 30 mm long. Capitula radiate, rays and discs yellow, turning reddish with age. Involucre 8 - 15 mm diam., bracts 7 or 8, lanceolate, 4 - 10 mm £ 2 - 3 mm, connate in basal 1/3. Ray fl orets 7 or 8, corolla tube 4 - 8 mm, limb oblanceolate, 8 - 12 £ 3 - 6 mm; ovary obovoid, appressed-puberulous with white twin-hairs; style branching at mouth of tube. Cypselae obovoid, 3 - 7 £ 2 - 4 mm, densely appressed-puberulous on ribs with myxogenic, white, twin-hairs; pappus 7 - 10 mm long, beige. Disc fl orets numerous, corolla tube 1 - 3 mm long, lobes lanceolate to ovate, 0.5 - 1.0 mm long; filaments 1 - 2 mm; ovary 3 - 6 mm long; style simple and cone-tipped; pappus of § 10 barbellate bristles, united basally.

Distribution and Ecology: Othonna pteronioides is restricted to the arid interior Western Cape, where it has been collected from south of Calvinia through the Tanqua Karoo and into the Great Karoo as far east as Beaufort West ( Fig. 5 ); on stony slopes at elevations below 1 200 m. Flowering from June to September.

Diagnosis: Othonna pteronioides is a very distinctive species readily recognised by its divaricately branched habit, the small (3 - 10 mm long), rather scattered leaves, oblanceolate to elliptic and thick-textured, thus elliptic in section, and the solitary peduncles developing into thorns at the branch tips ( Figs. 1C1-C 2 & 2D 1-D 2 ).

Although we have not been able to view the type specimen, Harvey (1865) is very clear in his description, and we have no doubt about its identity. The divaricate, thorny habit and small, sessile, oblanceolate leaves that he describes are diagnostic for the species.

3.5. Additional specimens examined

South Africa. NORTHERN CAPE: 3119 (Calvinia): 4.8 miles [8 km] from Calvinia (- AC), without date, Schmidt 593 ( PRE). WESTERN CAPE: 3219 (Wuppertal): Farm Koffee Water (- BC), 4 Aug 2007, Steyn 1144 ( NBG, PRE); Tankwa Karoo National Park, road between Jaghut and Varsfontein (- BD), 15 Aug 2011, Koekemoer 4203 ( PRE); Tankwa Guest Farm (- BD), 1 Aug 2006, Koekemoer 3148 ( PRE); Farm Tandschoonmaak, along Ceres-Calvinia road (- DA), 3 Jul 1974, Van Breda 4237 ( PRE). 3221 (Merweville): Dolfskraal (- BD), 5 Jul 1985 Shearing 1038 ( PRE); Krugerskop (- CB), 17 Jun 1989, Bryuns 3763 ( BOL); 3.5 miles [5.6 km] N of Prince Albert Road Station (- DC), 19 Sep 1953, Acocks 17122 ( PRE). 3222 (Beaufort West): Swart se Dam (- AC), 30 Jul 1984, Shearing 628 ( PRE). 3223 (Rietbron): Concordia, Rietbron (- CC), 04 Oct 2019, Magoswana 54 ( NBG); 22 Aug 1990, Dean 1035 ( PRE). 3319 (Worcester): Karoopoort, on road to Sutherland (- BA), 21 Sep 1981, Goldblatt 6294 ( PRE). 3320 (Montagu): Klein Roggeveld (- AB), without date, Helme 7315 ( NBG); Snyder ' s Kloof, Matjiesfontein (- AB), 16 Oct 1921, Foley 140 ( PRE); Whitehill (- AD), 10 Aug 1924, Compton 2895 ( BOL); 16 June 1941, Compton 10863 ( NBG); Zoutkloof, Laingsburg (- BB), 31 Aug 1936, Compton 6433 ( NBG). 3322 (Oudtshoorn): 21 km N of Prince Albert on road to Leeu-Gamka (- AA), 3 Sep 2012, Steyn 1896 ( NBG, PRE).

Figures

Fig. 5. Distribution of Othonna pteronioides.

Fig. 1. General morphology of the O. coronopifolia group. A.Habit of O. coronopifolia showing obovate to oblanceolate leaves and capitula with 7 or 8 ray florets; B. Habit of O.leptodactyla showing the linear or narrowly lanceolate leaves and capitula with 7 or 8 ray florets; C1-C2. Habit of O. pteronioides showing the small oblanceolate to elliptic leaves in axillary tufts, the divaricate branches ending in thorns and capitula on short-shoots; D. Habit of O. ramulosa showing the leaves fasciculate on short-shoots and capitula with 7 or 8 ray florets; E. Habit of O. spinescens showing the woody spinescent peduncles, the fasciculate leaves on short-shoots and an involucre with 7 or 8 ray florets; F1-F2 Habit of O. pavonia showing the pinnatisect leaves, the deep red or maroon stems, solitary inflorescence and capitula with 5 ray florets. Photographs: A-E by J. Manning; F1-F2 by L. Magoswana.

Fig. 2. Vegetative variability in species of the O. coronopifolia group (A1-A3, O. coronopifolia) (A1) showing dwarf plants growing along the coast, obovate-oblong, cuspidatemucronate leaves; (A2) plants with capitula on short-shoots, the peduncle mostly 50̅150 mm long; (A3) larger plants mostly with leaves often irregularly toothed or sometimes 3- pinnatifid, often in axillary tufts and on short-shoots; (B1-B2, O. leptodactyla) showing the linear or narrowly lanceolate leaves with linear lobes; (C1-C2, O.ramulosa) (C1) showing leaves mostly fasciculate on short-shoots, oblanceolate, inflorescence terminal on stem, old peduncles ending in thorns; (C2) leaves elliptic, narrow below and petiole-like, inflorescence on short-shoots along stem; (D1-D2, O. pteronioides) showing the divaricately branched habit, tips developing into thorns, the small oblanceolate-elliptic leaves, inflorescence terminal on stems or on short-shoots; (E1-E3, O. spinecens) showing an inflorescence that is either terminal on stems and then a divaricately branched corymb the peduncles becoming woody and spinescent after flowering, or solitary sub-erect capitula terminal on short-shoots and narrowly oblanceolate leaves; (F, O. pavonia) showing the pinnatisect leaves, an inflorescence of few to several capitula in lax corymbs and deep red to maroon stems when young and 5 ray florets and involucral bracts.