Gymnodiscus linearifolius DC., Prodr.

Magoswana, S. L., Boatwright, J. S., Magee, A. R. & Manning, J. C., 2016, A taxonomic revision of Gymnodiscus (Asteraceae: Senecioneae: Othonninae), a Greater Cape Floristic Region endemic *, South African Journal of Botany 106, pp. 71-77 : 76-77

2. Gymnodiscus linearifolius DC., Prodr. 6: 469 (1838).

Type: South Africa [Northern Cape], Africa Capensi ad Klein Namaqualand [Boschemans-karroo and Groenrivier ( Harvey, 1865)] [without date], Drège s.n. (G-DC, holo.; K-image!, SAM!, iso.)

Annual, rosettiform herb to 20 cm, glabrous at crown and in stem axils. Leaves basal, suberect-incurved, fusiform, 20–130 × 2–5 mm, mucronulate, succulent, green. Peduncles 2–6 mm diam., leaf-like cauline bracts linear, 3–15 × 2–3 mm., sessile, upper inflorescence bracts smaller, mucronulate 10–50 × 2–4 mm. Capitula in small cymose or sub-umbellate clusters aggregated into paniculate synflorescences; pedicels 5–45 mm long. Involucre campanulate to sub-globose, 4–10 mm diam.; involucral bracts 8 or 9, lanceolate to elliptic, 2.5–5.5 × 1.0– 2.5 mm. Ray fl orets, 8 or 9, perianth tube 1.0– 1.5 mm long, limb elliptic-ovate, 2.0–3.5 × 0.5–1.0 mm; ovary ellipsoid to narrowly oblong, glabrous; style included and branching just below mouth of tube. Disc fl orets 30, perianth ± 1.5 mm long, lobes ovate, 1–2 × 0.5 mm; anthers 1.0– 1.5 mm long; ovary narrowly ellipsoid, glabrous. Cypselas ellipsoid-obvoid, 1.0–1.5 × 0.5–0.8 mm, glabrous. Pappus 1–2 mm long. ( Figs. 1B and 4 ).

Distribution and ecology: A relatively local endemic of the Northern Cape, distributed from Aggenys in Bushmanland to Springbok and Kamieskroon in central Namaqualand ( Fig. 5 ); occurring on sandy flats and slopes below 1000 m. Flowering is from late May to October.

Diagnosis: Distinguished from G. capillaris by the fusiform leaves ( Fig. 4B ) and larger capitula, 4–10 mm diam., with 8 or 9 involucral bracts and ray florets and 30 disc florets. The perianth tube in the ray florets is longer than in G. capillaris , 1–1.5 mm long, with the style included and branching below the mouth of the tube ( Fig. 4D ). The ray ovaries and cypselas are glabrous ( Fig. 4D and F ).

Additional specimens seen

South Africa: Northern Cape: 2818 (Warmbad): Goodhouse (–CC), 26 Sep. 1930, Hennri 2227, 2235 (PRE). 2917 (Springbok): Rietkloof, near Garies and Springbok (–BC), 02 Sep. 1897, Schechter 11183 (BOL, PRE); 5 km NW of Springbok, Klipdam (–DB), 06 Jul. 2013, Helme 8014 (NBG); Nababeep, near golf course (–DB), 20 Aug. 1980, Le Roux 2682 (BOL); near Springbok (–DB), Sep. 1939, Gill 54335 (SAM) 2918 (Gamoep): Wortel (–BB), 21 Jun. 1898, Schlechter 115 (BOL, PRE); Aggenys, about 10 miles (16 km) W of farm house (–BB), 04 Sep. 1971, Wisura 2231 (NBG); About 100 km W of Pofadder towards Springbok (–BC), 13 Sep. 1973, Coetzee and Werger 1755 (PRE); near Ratelkraal (–CA), 07 Sep. 1950, Compton 22004 (NBG); eastern Namaqualand, farm Rietfontein, alongside Brakrivier (–CC), 13 Sep. 2007, Snijman 2168 (NBG). 2919 (Pofadder): 40 miles (64 km) W of Pofadder (–AD), 24 May 1961, Schliben 8997 (BOL, PRE); foot of Gamsberg, 40 miles (64 km) WSW of Pofadder (–AD), 25 May 1961, Leistner 2506 (BOL). 3017 (Hondeklipbaai): Namakwa National Park, Farm Avontuur, S of Hondeklipbaai road (–AD), 11 Aug. 2006, Koekemoer 3278 (PRE); Kamieskroon (–BB), Sep. 1954, de Vos 1722 (NBG); Kamieskroon (–BB), 24 Aug. 1941, Esterhuysen 5697 (BOL, PRE); ± 10 km from Kamieskroon on road to Skilpad Nature Reserve (–BB), 23 Sep. 2015, Manning & Magoswana 3546 (NBG); Skilpad Wildflower Reserve, at turning point (–BB), 22 Jul. 1996, Cruz 50 (NBG); 3 miles (5 km) above Wallekraal (–BC), Oct. 1924, Pillans 18107 (BOL); north of Darter's grave (–BD), 07 Sep. 1950, Maguire 293 (NBG); Brakdam (–BD), 03 Sep. 1951, Maguire 964 (NBG); Skilpad Nature Reserve, old fields S of homestead (–BB), 02 Jul. 1994, Glass 14 (NBG). 3018 (Kamiesberg): Around campsite between Bloudraai and Witwater (–AC), 14 Oct. 1981, Le Roux and Ramsey 779 (NBG); 10 km from Kamieskroon on road to Leliefontein (–AC), 24 Aug. 1995, Rodriguez-Oubina & Cruces 2053 (PRE).

Figures

Fig. 1. General morphology of Gymnodiscus. A. Habit of G. capillaris showing obovate–spathulate to oblanceolate basal leaves and capitula with 5 ray florets; B.habit of G. linearifolius showing the fusiform leaves and capitula with 8 or 9 ray florets.

Fig. 4. Gymnodiscus linearifolius. (A) flowering plant; (B) leaf; (C) involucral bract; (D) ray floret; (E) disc floret; (F) cypsela (ray floret); (G) ovary (disc floret); (H) style (disc floret); (I) anther; (J) pappus bristle.Voucher:Snijman 2168, NBG. Scales: (A&B) 1 cm; (C–E) 1 mm; (F–J) 500 μm. Artist:S.L. Magoswana.

Fig. 5. Distribution of G. linearifolius.