Calea myrtifolia Baker (Baker 1884

Calea myrtifolia (DC.) Baker Figs 2H, 6A, C, E, 7 Calea myrtifolia (DC.) Baker (Baker 1884: 260). – Meyeria myrtifolia DC. (Candolle 1836: 670). Calea myrtifolia var. paucidentata Baker (Baker 1884: 260) – Type: BRAZIL – Minas Gerais • Catas Altas, Serra do Caraça; fl., fr.; L. Riedel 1427; V.R. Bueno det. 2023; lectotype: LE [not found], designated in Pruski 2023; isolectotypes: G [00412260], K [000323152], P [02469708, 02469709, 02469710]. Type material BRAZIL – Minas Gerais • Diamantina; 1833; fl., fr.; A.C. Vauthier 320; V.R. Bueno det. 2023; lectotype: GDC [00456458], designated in Bueno et al. 2025b; isolectotypes G [00456458, 00222839], GH [00589157, 00589158], P [02140745, 02140746, 02140747], W [0043963]. Selected material examined BRAZIL – Minas Gerais • Barão de Cocais, lower slopes of Serra do Caraça; 27 Jan. 1971; fl., fr.; H.S. Irwin et al. 29263; V.R. Bueno det. 2021; RB [177374], UEC [2506], US [2818873] • Diamantina, Parque Estadual do Biribiri, caminho para Casa dos Ventos; 10 Jan. 2020; fl., fr.; V.R. Bueno 108; V.R. Bueno det. 2021; ECT [9543], HUFU [81516], ICN [203006] • Ibiá, Fazenda Santa Terezinha; 10 May 1986; fl., fr.; E.V.B. Paiva s.n.; V.R. Bueno det. 2021; UEC [79328] • São Sebastião do Paraíso, arredores da cidade; 8 Apr. 1945; fl., fr.; A.C. Brade 17649; V.R. Bueno det. 2021; RB [52670]. Description Shrubs 0.5–2.15 m tall. Stems cylindrical, striate, generally sparsely hirsute, sometimes sparsely puberulent or puberulent, rarely hispid, non-glandular, castaneous, internodes 3.2–24(–40) mm long. Leaves usually decussate, rarely decussate and whorled in the same stem, petiolate, petioles 0.9–2.5(–5.3) mm long; blades 0.79–6.03 × 0.36–3.08 cm, generally narrowly ovate, sometimes ovate or lanceolate, coriaceous, slightly discolorous, often concolorous, abaxial surface green, adaxial surface dark green or green, base rounded, apex acute, venation acrodromous basal, secondary veins conspicuous; margins usually revolute or slightly revolute, rarely flat, usually entire, often pauciserrate, sometimes oligoserrate, rarely multiserrate, 1–9(–13) teeth, 0.1–1.4(–2) mm long, commonly along the middle, sometimes base to middle or middle to apex, rarely just in base; abaxial surface usually glabrous, sometimes sparsely hirsute or sparsely scabridulous, rarely hispid, veins usually glabrous, sometimes sparsely scabridulous, rarely hispid or sparsely hirsute, glabrous or hispidulous, usually non-glandular, sometimes glandular-punctate, adaxial surface generally scabridulous, often glabrous. Capitulescence cymose dichasiform, slightly branched, axis 0–16.05(–24.05) mm long, 2–4 ramification orders, 2–14(–19) secondary branches; peduncle of capitulum 0.2–6.83(–9.55) cm long, usually pilose or hirsute, rarely puberulous, non-glandular, rarely glandular-punctate. Capitulum heterogamous, radiate. Involucre 5.9–11(–13) × 7.4–20 mm, generally hemispherical, often campanulate, rarely cylindrical; phyllaries 5-seriate, margins entire, conspicuously striate; outermost series of phyllaries foliaceous, green, usually scabridulous, sometimes glabrous, generally non-glandular, sometimes glandular-punctate; first series 4.5–7.2(–11.3) × 3.4–6 mm, usually shorter than involucre, rarely longer or equal, usually longer than second series, sometimes shorter, rarely equal, commonly very broadly ovate to ovate, sometimes broadly elliptic to narrowly elliptic, apex acute or obtuse, margins usually revolute or slightly revolute, sometimes flat, 3–6-veined; second series 5–6(–10.4) × 3.2–5.3 mm, generally broadly ovate or ovate, sometimes elliptic or narrowly ovate, apex usually obtuse, sometimes acute, margins usually entire, rarely pauciserrate, revolute, 6–14-veined; third series 4.8–8.1 × 4–6.2 mm, broadly ovate, ovate, suborbiculate, broadly elliptic or very broadly oblong, apex generally obtuse, sometimes rounded, margins usually entire, sometimes apex erose, flat, glabrous, scabridulous or sparsely scabridulous, usually non-glandular, sometimes sparsely glandular-punctate, commonly scarious, often apex foliaceous, greenish yellow or light yellow, often apex green, 10–12-veined; innermost series with margins flat, glabrous, scarious, greenish yellow or light yellow; fourth series 8.1–9.7 × (3.2–)3.4–4.7(–6.2) mm, usually oblong, sometimes obovate, narrowly obovate or narrowly oblong, apex rounded, 10–14-veined; fifth series 8.5–10.7 × (1.6–) 2.8–5.1 mm, generally narrowly oblong, often oblanceolate, sometimes narrowly obovate or obovate, apex usually rounded, rarely obtuse, 10–12-veined. Receptacle convex, holopaleaceous, with paleae 5.6–10 × 1–2 mm long, longer than corolla disc, narrow, generally narrowly oblong, often narrowly oblanceolate, rare narrowly elliptic, apex usually acuminate, rarely acute, concave, light yellow. Ray florets 8–20, pistillate, corolla liguliform, yellow, 9.9–17.5 mm long, tube 2.1–3.1 mm long, limb 7.7–14.5 × 2.5–4.2 mm, commonly narrowly oblong, sometimes elliptic, rarely very narrowly elliptic, apex acute, usually unlobed, rarely 2–3-lobed, 5–6-veined, abaxial surface usually sparsely glandular-punctate, rarely glandular-punctate, adaxial surface glabrous; style branches 1.0– 1.2 mm long, linear, yellow. Disc florets 45–85, monoclinous, corolla tubular, yellow, 4.25–7 mm long, tube 1.2–2.2 mm long, lobes 0.8–1.2 mm long, glabrous; anthers 2.5–2.8 mm long, light yellow, anther appendages apically ovate; style branches 0.8–1.1 mm long, linear, yellow. Cypselae 2.5–3 mm long, generally prismatic, sometimes obconic, nigrescent, ray cypselae 3-angled, disc cypselae 4-angled, glabrous, ribs sparsely pilose or pilose; pappus monotypic, monolength, free, formed by scales 10–14, 0.6–1.1 mm long, usually oblong, sometimes oblanceolate, apex obtuse or rounded, erose, margins entire. Distribution, habitat and phenology Calea myrtifolia occurs in Cerrado and the high-altitude grasslands of the Atlantic Forest exclusively in Minas Gerais (Bueno et al. 2023a) (Fig. 7); this occurrence is more restricted than previously recorded for this species (Pruski 2005). It inhabits cerrado rupestre, campo rupestre (Miola et al. 2021), riverine vegetation, wet grasslands associated with rock outcrops, sometimes floodable, and shrubby grasslands; at elevations of 950–1500 m. It species was collected flowering and fruiting throughout the year, but the highest number of collections is concentrated from January to March. Informal conservation status Endangered (EN) B2ab(ii,iii); C2a(i). Calea myrtifolia has an EOO of 254.329 km ² and an AOO of 268 km ². Like Calea marginata, C. myrtifolia has EOO and AOO indicating different threat categories, NT and EN, respectively. Interestingly, this species has an estimated AOO much larger than that of C. marginata, but a lower EOO due to fewer collection points. In addition to being restricted, formations of rupestrian grasslands and cerrado rupestre, as well as other formations associated with outcrops, are threatened by the impact of roads, accidental fire, and anthropic activity (Viana et al. 2005; Ribeiro et al. 2009; Miola et al. 2021; Pereira & Fernandes 2022). Due to this, it is estimated that there will be severe fragmentation coupled with a decline in the area of occupancy (B condition a, b). Recent collections made by the author and other collectors indicate that each subpopulation has fewer than 250 individuals (C2 condition a(i)). Thus, we propose that this species should be considered Endangered. Remarks Of late, Reis-Silva (2019) recommended the synonymization of C. myrtifolia var. paucidentata under C. myrtifolia, and more recently, Bueno (2023) also adopts the same criteria which is followed in this work. Among the eight species of C. subg. Meyeria, the one that most closely resembles C. myrtifolia is C. phyllolepis, and there were several identifications that confused one with the other. Together with C. subintegerrima and C. triantha, these form the most similar pairs of species within this subgenus. Calea myrtifolia differs from C. phyllolepis by mainly entire leaves (vs mainly serrate), first series of phyllaries of 3.4–6 mm wide (vs 6.1–8.9 mm), generally shorter second series of 5–6 mm long (vs 6.1– 11.3 mm), and usually ovate outermost series (vs frequently elliptic). In addition, these two species are allopatric: C. myrtifolia is restricted to Minas Gerais State, in the northern part of their combined range, while C. phyllolepis occurs in Rio Grande do Sul and Santa Catarina, farther south (Fig. 7). Another taxon that is also allopatric and is misidentified with C. myrtifolia is C. × parviantha (occurs in São Paulo and Paraná, Fig. 5; a distribution range intermediate between C. myrtifolia to the north and C. phyllolepis to the south). Much of the material collected of this nothospecies were misidentified as C. myrtifolia (Bueno et al. 2023a). Calea myrtifolia differs from this nothospecies in having pilose or hirsute peduncles, rarely puberulous (vs hispid), second series of phyllaries of 5–6 mm long (vs 7–10.4 mm long), commonly broadly ovate to narrowly ovate shape, sometimes elliptic (vs obovate or pandurifom or broadly elliptic), usually third series of phyllaries with 10–12 veins (vs 6–10), frequently shorter disc corolla lobes of 0.8–1.2 mm long (vs 1–1.7 mm long), glabrous cypselae apex (vs pilose or densely pilose), and scales of pappus frequently shorter of 0.6–1.1 mm long (vs 1.1–3 mm long).