Calea ser. Candolleanae V.R.Bueno, Gostel & G.Heiden, ser. nov.

Type species: Calea candolleana (Gardner) Baker (1884: 256) ≡ Meyeria candolleana Gardner (1848: 414–415) .

Description:—Herbs to shrubs up to 1.2 m tall. Leaves opposite, discolorous, sometimes concolorous, sessile or petiolate, petiole 0.2–4.2 (–13.6) mm long; blades 0.9–8.05 × 0.05–3 (–4.8) cm, narrowly elliptical, often lanceolate, sometimes linear, margins serrate, sometimes entire. Capitulescence cymose, dichasiform, often capitulum solitary, peduncle 1.5–16.3 (–21.7) cm long. Capitulum heterogamous, radiate; involucre campanulate, rarely cylindrical, 5.5–13 × (3.6–) 6.7–13.9 (–16) mm, wider than long, rarely longer than wide, 5–6-seriate, first series of phyllaries foliaceous to slightly foliaceous, the remaining phyllary series scarious; receptacle epaleaceous or partly paleaceous (hemipaleaceous or pauperpaleaceous; same frequency), paleae 4.7–6.5 mm long. Ray florets 5–10, pistillate, corolla yellow, (6–) 9.8–12.6 (–14.2) mm long, tube 1.9–3.5 mm long, limb (3.8–) 6.5–9.9 (–12.1) × (1.3–) 2.4–4.1 (–6.9) mm; style arms 0.5–1.3 mm long. Disc florets (12–) 18–30, bisexual, corolla yellow, 3.5–6 mm long, tube 1.2–1.5 (–2.1) mm long, lobes 0.4–1.2 mm long, tube longer than lobes, rarely equal; anthers 1.8–2.7 mm long, style arms 0.7–1 mm long. Cypselae blackish, (2.6–) 3.2–4.6 mm long, cylindrical; pappus monotypic, sometimes bitypic, (8–) 12–18 scales, 0.2–1.2 mm long, longer scales (when bitypic) 0.6–1.7 mm long, oblong or obovate.

Note:—The new series is characterized by narrow leaves, commonly long-pedunculate radiate capitula, campanulate involucre, epaleaceous or pauperpaleaceous to hemipaleaceous receptacle, and pappus scales 0.2–1.7 mm long.

The “ Calea pilosa complex”, comprising ten species according to Pruski & Hind (1998) and Pruski (2013), is not monophyletic (Bueno 2023). Therefore, this new series is defined here to include eight species and depicted here in a schematic way to show its placement in a phylogenetic context (Fig. 1). The new series comprises fewer species when compared to the former complex, due to the exclusion of C. hatschbachii and C. huanchacana .

Calea ser. Candolleanae is endemic of Eastern and Central Brazil (Fig. 2). This series occurs mostly in open vegetation types such as coastal scrubs, grasslands, and savannas. It comprises the following species: C. angusta Blake (1930: 258), C. bahiensis (Mattfeld 1925: 390) Robinson (1975: 428), Calea candolleana (Gardner 1848: 414) Baker (1884: 256), C. elongata (Gardner 1848: 415) Baker (1884: 255–256), C. gardneriana (Gardner 1848: 415) Baker (1884: 255–256), C. martiana Baker (1884: 256–257), C. melissifolia Baker (1884: 257), and C. pilosa Baker (1884: 257) . Although some specimens found in Mato Grosso do Sul and Paraguay were previously labeled as C. candolleana and C. pilosa, they do not correspond to these species and are close to Calea rupicola Chodat (1903: 726) .