Gerbera sinuata (Thunb.) Spreng., Syst. Veg.

Manning, J. C., Simka, B., Boatwright, J. S. & Magee, A. R., 2016, A revised taxonomy of Gerbera sect. Gerbera (Asteraceae: Mutisieae) *, South African Journal of Botany 104 (1), pp. 142-157 : 146

1. Gerbera sinuata (Thunb.) Spreng., Syst. Veg. 3: 575 (1826).

Arnica sinuata Thunb, Prodr. Pl. Cap. : 154 (1800). Gerbera burmanni var. sinuata (Thunb.) Harv. in Harv.& Sond., Fl.Cap.3: 521 (1865).

Type: South Africa, Thunberg s.n. Herb. Thunb. 20,010 (UPS-THUNB, holo.—microfiche!)

Acaulescent perennial. Leaves suberect, blades narrowly elliptic or oblong to ovate, (20–)28–105 × 18–40 mm, acute, base truncate to attenuate, margins irregularly crenulate to crenately incised or lobed, incisions finely 1- to 4-toothed, 3–11 × 2–5 mm, revolute, strongly discolorous, upper surface glabrous, rarely with thin patches of whitish wool, dull yellowish green to dark green, under surface whitish–greyish felted; petiole whitish woolly but densely silky at base. Scapes bracteate, 150–300(− 550) mm long, thinly brownish–yellowish felted, bracts ±4-subseriate, lanceolate, 5–14 mm long, whitish-woolly. Capitula 25–60 mm diam. Involucre campanulate; bracts ±3-subseriate, inner longest, 10–15 mm long, thinly to densely whitish-woolly with purple, membranous margins, acute to acuminate. Ray fl orets ± 20, usually pink to magenta or rarely white, sometimes tipped pink, with darker under surface, perianth tube 7–8 mm long, lower limb 20–25 mm long, upper limb 4–5 mm long, staminodes present. Disc fl orets brown, tube 6 mm long, lower limb 4–5 mm, upper limb 3–4 mm long; anther appendages dark brown to black. Cypselas flask-shaped, 5–6 mm long including a short beak ± 1.5 mm long. Pappus bristles 11–12 mm long, snow white.

Flowering time: September to February

Distribution and ecology: restricted to the western coastal mountains of Western Cape, from the Piketberg and central Cederberg along the Olifants River Mountains to the Witzenberg near Ceres and the Elandskloofberge near Gouda, occurring on stony sandstone slopes ( Fig. 3 ). Flowering takes place only after fire.

Diagnosis: distinguished by the crenately incised or lobed leaves ( Fig. 2F ) with finely toothed incisions, the upper surface glabrous and the under surface densely whitish-felted, the mostly pink to reddishpurple or magenta rays ( Fig. 1B & C ), and the snow white pappus. Populations on the Piketberg are uniformly pink to magenta-flowered ( Fig. 1C ) but elsewhere both white-flowered and pink-flowered forms occur. Gerbera crocea , which may also have dark pink to purple rays, has leaves with crenate to sinuate margins and thinly tomentose or subglabrous under surface ( Fig. 2E ). Gerbera linnaei , the only other species with markedly incised leaves, has deeply and often quadrately pinnatisect leaves ( Fig. 2B ), and glabrous involucral bracts.

This species was not completely understood by Hansen (1985), who included most collections known to him in G. crocea , where they are anomalous in their incised leaves with whitish-felted under surface. Two additional collections, Lewis 6211 (NBG) and Martin 332 (NBG) from the Piketberg, which he mistakenly thought were collected on the Cape Peninsula, were suggested to be hybrids G. crocea × G. wrightii , purportedly combining the irregularly sinuate leaves of the former with the scape and leaf tomentum of the latter ( Hansen, 1985: 15). In reviewing the species for this account, we identified that these anomalous collections with felted leaf under surface occupy a distinct geographical range largely to the north of typical G. crocea . Typical subglabrous populations of G. crocea have been collected at Sneeugat in the Witzenberg (Phillips 1785, SAM), which we interpret as additional evidence supporting the recognition of the northern, felted populations as a geographically and morphologically distinct species.

Additional collections examined

South Africa. WESTERN CAPE: 3218 (Clanwilliam): Piketberg, lower east slopes of Kapteinskloof Mt, Boskloof, (− DC), 20 Oct 1935, Pillans 7839 (BOL); Boskloof, (− DC), Sep 1941, Stokoe s.n. (SAM); top of Piketberg Mtn, (− DC), 8 Sep 1965, Lewis 6211 (NBG). Piketberg Mtn, (− DC), 25 Sep 1949, Martin 332 (NBG), 27 Feb 1967, Thomas 393 / 65 (NBG); burned rocky slope near Dreyerslvei (− DC), 1 Sep 1992, Goldblatt & Manning 9350 (MO, NBG); Piketberg, Die Plaat, (− DC), 24 Dec 2014 [fruiting], Manning 3487 (NBG). 3219 (Wuppertal): Keerom, stony W slopes of Olifants River Mtns, (− CC), 4 Dec 1950, Esterhuysen 17,927 (BOL). 3319 (Worcester): between Rosendalfontein and Visgat, (− AA), 25 Nov 1941, Pillans 9669 (BOL); Ceres Road, (− AC), 11 Nov 1896, Schlechter 9075 (BOL); lower slopes of Ontongsberg, (− AC), 11 Nov 1941, Isaac 950 (BOL); foot of Castle Rock, Mitchell's Pass, (− AD), 16 Nov 1947, Esterhuysen 14,152 (BOL).

Figures

Fig. 3. Distribution of Gerbera sinuata.

Fig. 2. Leaf upper and under surfaces in Gerbera section Gerbera. A.G. wrightii (Compton 15457, NBG).B. G. linnaei (Rourke I280, NBG).C. G. serrata (McDonald 1486, NBG). D. G.ovata (Goldblatt & Porter 12496, NBG). E. G. crocea (E1. Rourke 774, NBG. E2. Taylor 4383, NBG, note the glabrous under surface). F.G. sinuata (Lewis 6211, NBG).G. G. tomentosa (G1. Kruger 1136, NBG.G2.Nel s.n., NBG).H.G.grandis (Williams 3695, NBG).Scale bar = 10 mm.

Fig. 1. General morphology of Gerbera section Gerbera. A.G. wrightii; B & C.G.sinuata; D & E. G.linnaei; F.G.serrata; G. G. crocea, note the glabrous leaf under surface; H.G.tomentosa; I. Imbricate involucral bracts of G. tomentosa; J.Subseriate involucral bracts of G.crocea. Photographs: A:N.Helme; B, D, E, F, H: J.C.Manning; C: I.Ebrahim; G, I, J: T.Rebelo.