Cotula pruinosa ((E.Mey. ex. DC.)) Jakoet & Magee, 2019

Jakoet, A., Mucina, L. & Magee, A. R., 2019, The pseudo-radiate buttons: A taxonomic revision of the Cotula turbinata group (Asteraceae; Anthemideae) and the description of two new species *, South African Journal of Botany 121, pp. 282-293 : 290-291

5. Cotula pruinosa (E.Mey. ex. DC.) Jakoet & Magee, comb. nov.

Cenia pruinosa E.Mey. ex DC., Prodr. 6: 82 (1838); Dietrich, Syn. Pl. 4: 1606 (1847). Cenia turbinata var. discolor Harv. , in Harvey & Sond., Fl. Cap. 3: 185 (1865). Type: South Africa, Cap. Bonae-Spei [ Cape of Good Hope ], s.d., Drege 220 (G-DC barcode G00460752 , holo.–image!).

Cenia expansa Compton, J.S. African Bot. 19: 112 (1953), syn. nov. Type: South Africa. Western Cape, Malmesbury (3218): Kotze, mouth of the Berg River (–CA), Sep 1944, Compton 15,936 (NBG, holo.!, PRE!, BOL!, iso.).

Cenia anthemoidea DC., Prodr. 6: 83. 1838; Dietrich Syn. Pl. 4: 16–19 (1847). Type: South Africa: Kaapse Vlakte [Cape Flats], s.d., Drege 6365 (G-DC, holo.–image!, P–photo!, iso.).

Annual herb, 60–520 mm. Not rooting at the nodes. Stems usually erect to decumbent, 15–270 mm long, sparsely hairy. Leaves alternate, decreasing in length towards upper part of plant, 2- or 3-pinnatisect, 25–65 × 5–30 mm, obovate to oblanceolate, green to dark green, petiole-like base usually present; lobes linear, 1–4 × 0.5–1.0 mm, ± terete, becoming progressively smaller towards the leaf base, sparsely hairy, apices acute. Capitula heterogamous, 5–20 mm in diameter, disciform, pseudo-radiate, disc face convex, solitary, terminal, pedunculate; peduncles 14–85 mm long, apically swollen in fruit, swelling obconical, 3–20 × 2–10 mm, dark green, hollow. Involucre hemispherical; bracts 2- or 3- seriate, broadly ovate, 1.5–4.0 × 0.5–5.0 mm, apex obtuse, glabrous, green, opaque, apex and margins scarious, brownish, 3- to 5- veined. Receptacle shallowly convex. Filiform fl orets female, in single outermost series, pedicellate, corolla absent; ovary elliptic to slightly obovate, broadly winged, slightly concave on the ventral surface, glandular; pedicels linear, pedicels of filiform florets 0.5 mm at maturity. Disc fl orets bisexual, heteromorphic, pedicellate, 4-lobed; lobes mostly triangular, ca. 0.4 mm long, florets in outermost series with the dorsal lobe greatly enlarged to resemble a ray limb, dorsal lobe ±2 times length of other three lobes, obtuse to elliptic, ca. 2.0– 3.5 mm long; tube not basally draping over ovary; limbs bell- to cup-shaped, yellow; pedicels of disc florets 0.1–0.3 mm long, gradually decreasing in length towards center. Cypselae heteromorphic; those of filiform florets ovoid, 1.4–2.4 × 1.2–1.8 mm, broadly winged, wing ca. ⅓ times width of the female portion, slightly concave on outer surface, sessile glands present; those of disc florets ovoid, 1.2–1.7 × 0.7–1.0 mm, marginal ribs prominent, sessile glands present; band of myxogenic cells on ventral surface flanking the fertile portion; resin canals absent.

Diagnostic characters: Cotula pruinosa has in the past been considered to represent a yellow flowered variety within Cotula turbinata but is further distinguished here by the cypselae of disc florets in which the ventral surface has conspicuous bands of myxogenic cells flanking the fertile portion ( Fig. 3. E 2 ). It shares this cypsela trait with Cotula duckittiae , but can be readily distinguished from the latter by the yellow ( Fig. 2. H ) rather than orange pseudo-ray florets with the dorsal lobe only two times the length of the other three lobes (almost four times the length in C. duckittiae ) and the convex disc face (concave to flat in C. duckittiae ). Cenia expansa , previously treated as a synonym of C. duckittiae ( Manning and Goldblatt, 2012) , is treated here rather as conspecific with C. pruinosa . Cenia expansa and C. pruinosa are superfi-cially quite different particularly when comparing typical plants of C. expansa from deep coastal sands along the West Coast. Cenia expansa is generally larger in habit and in the size of the flowerheads. However, there is significant overlap in both these characters and at several sites where they co-occur we observed a full range of intermediates which would be impossible to assign. As a result we treat them here as one species, C. pruinosa .

Distribution and ecology: Cotula pruinosa is the most widespread in the group, occurring from Clanwilliam to Struisbaai in the Western Cape Province ( Fig. 8 ). It favors deep coastal sands (in strandveld), and at base of rocky (granite, sandstone) outcrops. Soils are more sandy (and less disturbed) than in habitats supporting C. turbinata . Secondary C. pruinosa invades on sandy road verges (for instance in surrounds of Malmesbury, in Cape Town, and around Stellenbosch and Paarl). Flowering is usually from late winter to mid-spring (August–October) but has been found to continue in some conditions into summer (December–February).

Additional specimens examined: South Africa. WESTERN CAPE: 3217 (Vredenburg): Vredenburg (− DD) , 6 Aug 1962, Barker 9677 ( NBG) ; Vredenburg district, Swartriet farm, Jakobsbaai (− DD) , 7 Aug 1993, Boucher 5808 ( NBG) . 3218 (Clanwilliam): Saldanha, Tskor smelting plant site, Vredenburg district (– CC) , 2 Sep 1995, Boucher 5950 ( NBG) ; 7 Sep 1995, Rode 275 ( NBG) ; Sauer (– DC) , 10 Sep 1949, Barker 5778 ( NBG) ; 1 Oct 1943, Compton 15,085 ( NBG) . 3317 (Saldanha): Granite koppie just outside Saldanha (– BB) , 6 Oct 1981, Hugo 2926 ( NBG) . 3318 (Cape Town): Farm Geelbek, Langebaan (− AA) , 4 Sep 1986, Bosenberg & Rutherford 80 ( NBG) ; 24 Aug 1947, Compton 19,904 ( NBG) ; Jul 1980, Hugo 2422 ( NBG; PRE); Hopefield Area, Elandsfontein (− AA) , 16 Sep 2008, Boucher 7563 ( NBG) ; Postberg Nature Reserve, Langebaan Peninsula (− AA) , 13 Aug 1975, Boucher 2793 ( NBG; PRE); ± 7 km SE of Hopefield, Kersbosch Dam (– AB) , 26 Aug 2008, Helme 5592 ( NBG) ; Hout Bay , Cape Peninsula (– AB) , 20 Sep 1941, Compton 11,757 ( NBG) ; Koperfontein (– AB) , 14 Sep 1953, Barker 8067 ( NBG) ; Malmesbury Div., near Yzerfontein (– AC) , 1 Aug 1938, Barker 420 ( NBG) ; Tienie Versveld (– AC) , 29 Aug 2014, Magee & Jakoet 1104 ( NBG) ; 1 Aug 2013, Magee, Powell & Boatwright 1025 ( NBG) ; 7th gate at Bok Point (– CB) , 15 Sep 1940, Compton 9411 ( NBG) ; Bokbaai farm, near Darling (– CB) , 20 Sep 1968, Mathews 10,587 ( NBG) ; Duynefontein, Koeberg (– CB) , 15 Sep 1987, Bosenburg & Rutherford 231 ( NBG) ; entrance to Rondeberg Nature Reserve , road to homestead (– CB) , 29 Aug 2014, Magee & Jakoet 1107 ( NBG) ; Mamre flats (– CB) , 8 Oct 1942, Compton 13,887 ( NBG) ; Melkbosch Strand (– CB) , 8 Sep 1940, Compton 9324 ( NBG) ; Kenilworth Racecourse, at Wetton road patch (– CD) , 22 Oct 1968, Esterhuysen 32,052 ( NBG) ; 9 Sep 2014, Magee & Jakoet 1115 ( NBG) ; Kirstenbosch, road to Research Centre, in undisturbed Fynbos (– CD) , 26 Aug 2014, Magee & Jakoet 1110 ( NBG) ; Milnerton (– CD) , 17 Sep 1913, Phillip s.n. ( NBG) ; Paarden Island (– CD) , 2 Aug 1940, Bond 425 ( NBG) ; 18 Jun 1949, Rondebosch Commons (– CD) , Heginbotham 7 ( NBG) ; 9 Sep 2014, Magee & Jakoet 1111 ( NBG) ; 9 Sep 2014, Magee & Jakoet 1113 ( NBG) ; road to Bokbaai from Granzekraal (– CD) , 29 Aug 2014, Magee & Jakoet 1105 ( NBG) ; Signal Hill (– CD) , Sep 1807, Thode 5847 ( NBG) ; Malmesbury division, Burgers Post Farm, Near Pella , Fynbos Biome Research Site (− DA) , 31 Aug 1979, Boucher & Shepherd 4513 ( NBG) ; 14 Nov 1079, Boucher & Shepherd 4899 ( NBG) ; Uitspan, Kalbaskraal , old serradella land (− DA) , 12 Aug 1969, Marsh 1207 ( NBG) ; 2nd Terrace on golf course (− DD) , 22 Sep 1960, Van Reusburg 305 ( NBG) . 3319 (Worcester): Ceres Valley, Wolvenhuis 371 (− AD) , 20 Aug 1987, Cloete & Cillie 58 ( NBG) ; 20 Aug 1987, Cloete & Cillie 60 ( NBG) . 3418 (Simonstown): Northern side of Muizenberg Mountains , South Peninsula (– AB) , 28 Sep 1972, Wisura 2479 ( NBG) ; Red Hill (– AB) , 14 Aug 1960, Taylor 2555 ( NBG) ; 18 Aug 1962, Taylor 3724 ( NBG) ; Simonstown Div., Silvermine Nature Reserve , near Cape Town (– AB) , 17 Nov 1994, Watson & Panero 94–15 ( NBG) ; Simonstown (– AB) , 23 Nov 1964, Taylor 6068 ( NBG) ; Olifantsbosch, Cape Peninsula (− AD) , 4 Oct 1959, Rycroft 2191 ( NBG) ; Isoetes Vlei, Cape Flats, Wynberg Dist. (– BA) , 22 Jul 1970, Strauss 20 ( NBG) ; Strandfontein (– BA) , 18 Sep 1942, Compton 13,701 ( NBG) ; Cascades, Betty's Bay (– BD) , s.d., Taylor 4380 ( NBG) ; Dawidskraal flats (– BD) , 28 Aug 1971, Bohlman & Borrowski 24 ( NBG) ; Harold Porter Botanic Gardens, Betty's Bay, Caledon (– BD) , 20 Oct 1970, Ebersohn s.n. ( NBG) . 3419 (Caledon): “Die Mond”, Hermanus (– AC) , 1 May 1933, Jordaan 852 ( NBG) ; Kleinmond, in Isakrivier, Caledon district (– AC) , 21 Jan 1947, de Vos 421 ( NBG) ; Fernkloof Nature Reserve, Hermanus (− AD) , 20 Sep 1976, Woodvine 3 ( NBG) ; Vogelgat, Base Camp (− AD) , 15 Sep 1978, Williams 2586 ( NBG) ; 21 Jun 1982, Williams 3253 ( NBG) ; Gansbaai (– CB) , 24 Aug 1946, Compton 18,162 ( NBG) ; Uilkraals River, N bank of river 1.5 km from bridge (– CB) , 6 Aug 1987, O'Callaghan 6/8/7 ( NBG) ; Overberg, Pearly Beach, end of the Main Road coast (− DA) , 9 Oct 2014, Magee & Jakoet 1141a ( NBG) ; 10 Sep 2006, Mucina 100,906/20 ( NBG) ; ± a few hundred metres north of the Groot Hagelkraal homestead (− DA), 25 Jul 1995, Paterson-Jones 460 ( NBG) . 3420 (Bredasdorp): Agulhas Plain, Struisbaai , road to Plaat (– CC) , 14 Oct 2006, Mucina 141,006/08 ( NBG) . Precise locality unknown: Cape Town to Malmesbury, 6 Sep 1973, Montgomery 492 ( NBG) .

Figures

Fig.3. Cypsela variation in the Cotula turbinata group.(A) C.calcicola: (A1) cypsela of filiform floret; (A2) cypsela of disc floret;(B) C.discolor: (B1) cypsela of filiform floret; (B2) cypsela of disc floret;(C) C.duckittiae: (C1) cypsela of filiform floret;(C2) cypselaof disc floret;(D)C.perennans: (D1) cypsela of filiform floret;(D2) cypsela ofdisc floret;(E) C.pruinosa: (E1) cypsela of filiform floret;(E2) cypsela of disc floret;(F) C.turbinata: (F1) cypsela of filiform floret; (F2)cypsela of disc floret.Vouchers:(A1) & (A2) Magee & Jakoet 1138a (NBG);(B1) &(B2) Jakoet 54 (NBG);(C1) & (C2) Magee & Jakoet 1127 (NBG);(D1) Esterhuysen 33,481 (BOL);(D2) Esterhuysen 33693 (BOL) (E1) & (E2) Magee & Jakoet 1111 (NBG);(F1) & (F2) Magee & Jakoet1114 (NBG).Scale: 1 mm.

Fig. 2. Floret variation and position in the Cotula turbinata group. (A) Diagram representing the positon of the different florets in a typical capitulum, with black circles representing the filiform florets, diamond shape representing the pseudo-ray florets and the white circles representing the disc florets; (B) typical filiform floret from C.pruinosa; (C) typical disc floret from C. duckittiae; (D-I) pseudo-ray florets in C. calcicola (D), C. discolor (E), C. duckittiae (F), C. perennans (G), C. pruinosa (H), and C. turbinata (I). Vouchers: (B) Jakoet & Magee 1111 (NBG); (C) Magee & Jakoet 1127 (NBG); (D) Magee & Jakoet 1138a (NBG); (E) Jakoet 54 (NBG); (F) Magee & Jakoet 1127 (NBG); (G) Esterhuysen 35120 (BOL); (H) Jakoet & Magee 1111 (NBG); (I) Magee & Jakoet 1114 (NBG). Scale: 1 mm.

Fig. 8. Known geographical distribution of Cotula pruinosa.