Pteronia flava Bello, Magee & Boatwr., 2020

3. Pteronia flava Bello, Magee & Boatwr. View in CoL , sp. nov.

Type:— SOUTH AFRICA, Northern Cape Province, Sutherland (3220): Roggeveld, Die Puts, survey Plot 305 (–BD), 20 September 2004, Rosch 258 (holotype NBG!) .

Evergreen perennial shrub ca. 0.6 m in height, much branched; branches erect, glabrous, greyish. Leaves decussate, slightly contiguous at base, crowded, simple, lanceolate, 3–4 × ± 2 mm, subterete, somewhat flattened on lower part, succulent, glabrous; apex obtuse; margins finely and shortly ciliate. Capitula 8- to 10-flowered, terminal, solitary, sessile. Involucre turbinate, 10–15 × 4–6 mm, 4- to 6-seriate; involucral bracts glabrous, lanceolate; apex subacute, dark-coloured; margins ciliate; outermost bracts 3–4 mm long; middle bracts 6–7 mm long; innermost bracts 10–11 mm long. Florets bisexual; corolla bright yellow, tubular, 10–11 mm long; limb 5-lobed, widening upward; tube glabrous; anthers 3–4 mm long; apical appendages acute; filament not swollen distally; style branched, 10–11 mm long; branches somewhat flattened, ca. 3 mm long, stigmatic-papillate. Pappus of barbellate bristles, biseriate, connate at base, 7–9 mm long, shorter than florets at fruiting stage, straight, straw-coloured. Cypselae ovate, 3–4 × ± 2 mm, dorsiventrally flattened, contracted into a neck at apex, glandular and finely villous ( Figure 4 View FIGURE 4 ).

Diagnostic characters:— Pteronia flava has been confused with P. glomerata Linnaeus (1782: 356) in the past. Both species share the glomerate, lanceolate, ciliate and succulent leaves, but P. flava can be distinguished by the greyish branches (greenish in P. glomerata ) and the yellowish bracts with dark-coloured apices (bracts greenish with light-coloured apices in P. glomerata ). Pteronia flava could also be confused with P. empetrifolia De Candolle (1836: 363) but is easily distinguished by the smooth greyish branches (coarse in P. empetrifolia ) and ciliate leaf margins (entire in P. empetrifolia ).

Distribution and Ecology:— Pteronia flava occurs on the Roggeveld and Nieweveld mountains of the Northern Cape escarpment from near Calvinia to Loxton ( Figure 5 View FIGURE 5 ). It favours sandy soil from 980 to 1466 m (a.s.l.). Flowering occurs in spring and midsummer (September–January).

Additional specimens examined:— SOUTH AFRICA. Northern Cape Province: 3119 (Calvinia): Bloukrans Pass. 23 km south of Calvinia (–DB), 15 October 1989, Greuter 21784 ( PRE) . 3122 (Loxton): 24.7 km west of Loxton on road to Victoria West (–BC), 11 October 2008, Potts s.n ( BOL) .