Cotula perennans Jakoet, Mucina & 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 : 286-287

2. Cotula perennans Jakoet, Mucina & Magee sp. nov. Type: South Africa, Western Cape, Somerset West (3418): Helderberg (–BB), Table Mountain , Kasteels' Poort (–CD), 12 Feb 1974, Esterhuysen 33,481 ( NBG, holo.!; BOL!, iso).

Perennial herb, 80–415 mm. Rooting occasionally at the nodes. Stems usually spreading to erect, 30–350 mm long, sparsely hairy. Leaves alternate, decreasing in length towards upper part of plant, 2- or 3-pinnatisect, 6–112 × 5–17 mm, oblanceolate to obovate, green, petiole-like base absent; lobes linear to oblanceolate; 1–3 × 0.5–1.5 mm; ± flat, becoming progressively smaller towards the leaf base, sparsely hairy, apices acute to mucronate. Capitula heterogamous, 4–11 mm in diameter, disciform, pseudo-radiate, disc face convex, solitary, terminal, pedunculate; peduncles 22–142 mm long, apically swollen in fruit; swelling obconical, 0.5–7.0 × 1–8 mm, green to light brown, hollow. Involucre hemispherical; bracts 2- or 3-seriate, broadly ovate, 1.2–1.5 × 1–4 mm, apex obtuse to rounded, 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 or occasionally with a rudimentary limb present next to style; ovary elliptic, broadly winged, slightly concave on the ventral surface, glandular, pedicels linear; pedicels 0.9 mm long at maturity. Disc fl orets bisexual, heteromorphic, pedicellate, 4-lobed, lobes mostly triangular, ca. 0.3 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, elliptic, ca. 1.5–2.0 mm long; tube not basally draping over ovary; limbs bell- to cup-shaped, usually white or with those in inner series often yellow; pedicels 0.3–0.6 mm long, gradually decreasing in length towards the center. Cypselae heteromorphic; those of filiform florets ovoid, ca.1.6–2.5 × 1.3–1.5 mm, broadly winged, wing ca. ¼ times width of the fertile portion, slightly concave on outer surface, sessile glands present; those of disc florets ovoid, 1.8–2.2 × 0.8–1.2 mm, marginal ribs prominent; sessile glands present, myxogenic cells absent; resin canals absent.

Diagnostic characters: Cotula perennans is one of only two perennials in the group. It differs from the only other perennial species, C. discolor , by having white pseudo-ray florets ( Fig. 2. G ; yellow in C. discolor ), leaves decreasing in length along the stem towards the peduncle (uniform and densely clustered below the peduncle in C. discolor ), and prominently flattened leaf lobes (subterete in C. discolor ). Rooting occasionally occurs at the nodes (rooting absent at nodes in C. discolor ).

Distribution and ecology: Cotula perennans occurs at higher altitudes (450 m and 1070 m) on the Cape Peninsula (Table Mountain and Noorhoek Peak), Hottentots Holland Mountains (Stellenbosch Berg, Swartboskloof, Helderberg, and Guardian Peak ( Fig. 5 ). It can be found in sheltered rocky niches, usually at the base of rocky (sandstone) cliffs, shaded and moist, nutrient-poor sandy soils. The surrounding vegetation belongs to Cape Peninsula Sandstone Fynbos and Hawequas Sandstone Fynbos ( Rebelo et al., 2006). Flowering is from mid-spring to the beginning of winter (October to June).

Additional specimens examined: South Africa. WESTERN CAPE: 3418 (Somerset West): Noordhoek Peak (– AB), 25 Nov 1978, Esterhuysen 35,120 ( BOL) ; Disa Gorge, Helderberg (– BB), 14 Nov 1948, Esterhuysen 14,647 ( NBG) ; 14 Nov 1948, Esterhuysen 14,648 ( BOL) ; 19 Mar 1977 ( BOL) , Esterhuysen 34,546 (BOL); Helderberg, Somerset West (– BB), 14 Nov 1948, Esterhuysen 14,666 ( BOL) ; 14 May 1961, Esterhuysen 29,042 ( BOL) ; lower slope of Guardian Peak, Hottentots Holland Mountains (– BB), 7 Oct 1945, Esterhuysen 11,944 ( BOL) ; ravines of the Helderberg (– BB), 3 Feb 1948, Parker 4313 ( BOL) . 3318 ( Cape Town ): Stellenbosch Berg (– BB), 5 May 1978, Esterhuysen 34,860 ( BOL) ; Table Mountain (– CD), 28 May 1972 ( BOL) , Esterhuysen s.n (BOL); 7 Jun 1987, Esterhuysen 36,526 ( BOL) ; Table Mountain , Kasteels' Poort (– CD), 23 Oct 1974, Esterhuysen 33,660 ( BOL; NBG) ; Table Mountain , Pimple Gorge (– CD), 10 Nov 1974, Esterhuysen 33,693 ( BOL) ; Gt. Drakenstein Mnt (− DD), 12 Dec 1943, Esterhuysen 9543 ( BOL) ; 20 Sep 1945, Esterhuysen 11,872 ( BOL) ; 13 May 1979, Esterhuysen 35,208 ( BOL) ; Jonkershoek, along the path up Swartboskloof (− DD), 4 Feb 1973, Esterhuysen 33,136 ( BOL) ; 16 Apr 1972, Esterhuysen 32,856 ( BOL) ; Jonkershoek, near top of Nerine Kloof (− DD), 16 Apr 1978, Esterhuysen 34,919 ( BOL) ; Jonkershoek Forest Reserve (− DD), 20 Mar 1977, Esterhuysen 34,550 ( BOL) .

Figures

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. 5. Known geographical distribution of Cotula perennans.