Calea malmeana V. R. Bueno & G. Heiden 2026, nothosp. nov.

Calea × malmeana V.R.Bueno & G.Heiden nothosp. nov. urn:lsid:ipni.org:names:77372517-1 Fig. 5, 11 Diagnosis Calea × malmeana nothosp. nov. is intermediate morphologically compared to the parents (Calea marginata and C. parvifolia), it is distinct from C. marginata by glandular-punctate stems, peduncle, and disc floret corolla (vs non-glandular) and reticulodromous venation leaf (vs acrodromous basal). It can be individualized from C. parvifolia by inconspicuous secondary venation leaf (vs conspicuous), white margin leaf and of outermost series of phyllaries (vs green). Etymology The epithet honors Gustaf Oskar Andersson Malme (1864–1937), a Swedish botanist who served as curator at the Museum of Natural History in Stockholm, and who made two important collecting expeditions through Brazil. In addition, he published over 120 names for Asteraceae (Tropicos 2025) and published a paper on Calea (Malme 1933), where he recorded the hybrid nature of some species, without formally describing them. Type material Type BRAZIL – Paraná • Ponta Grossa, Fortaleza, in subpaludosis; 26 Feb. 1910; fl., fr.; P.K.H. Dusén 9553 a; V.R. Bueno det. 2023; holotype: S [17-26715]. Paratypes BRAZIL – Paraná • Jaguariaíva, Lago Azul; 5 Mar. 2006; fl., fr.; E. Barbosa & E.F. Costa 1293; V.R. Bueno det. 2023; CESJ [48441], FURB [7023], MBM [318471] • Ponta Grossa, formador do Rio Tibagi, cruzamento BR-376; 31 Jan. 1999; fl., fr.; S.R. Ziller et al. 1722; V.R. Bueno det. 2023; EFC [8779], MBM [242494] • Palmeira, Rio dos Papagaios; 7 May 1981; fl., fr.; L.T. Dombrowski et al. 12761; V.R. Bueno det. 2023; MBM [300633]. Description Shrubs 0.5–1.5 m tall. Stems cylindrical, corrugate, glabrous to densely scabridulous or sparsely hispidulous, densely glandular-punctate or glandular-punctate, castaneous, internodes 10.9–27.6(– 34.4) mm long. Leaves decussate, petiole 0,9– 2.3 mm long; blades 1.3–3.97 × 0.4–1.1 cm, commonly lanceolate, often narrowly elliptic to narrowly oblong, chartaceous, generally concolorous, often slightly discolorous, usually green, often surface adaxial dark green, base generally obtuse, rarely rounded, apex acute or obtuse, venation reticulodromous, secondary veins inconspicuous; margins generally slightly revolute or revolute, sometimes flat, entire, generally thin, rarely thickened, white; abaxial surface densely punctate, surface adaxial generally glabrous, rarely sparsely strigose. Capitulum usually solitary, rarely capitulescence cymose dichasiform, slightly branched, axis 0–2.74 mm long, branching to 2 nd ramification order, 2–4 secondary stems; peduncle 0.8–4.1 cm long, sparsely hispidulous to hispidulous or hispid to densely hispid, sparsely glandular-punctate or densely glandular-punctate. Capitulum heterogamous, radiate; involucre 8.3–13 × 11.1–15.1 mm, campanulate or hemispherical. Phyllaries 5-seriate; outermost series of phyllaries apex obtuse, margins apex slightly revolute, generally entire, rarely pauciserrate, white, usually inconspicuously striate, sometimes conspicuously; first series 10.5–12.3 × 3–4.8(–6.6) mm, commonly longer than involucre, often shorter, longer than second series, generally narrowly elliptic, sometimes panduriform or obovate, usually sparsely glandular-punctate, sometimes glandular-punctate, rarely glandular-foveate, foliaceous, green, 2–4-striate; second series 9.8–11.5 × 3.8–4.8(–6.5) mm, generally narrowly elliptic or panduriform, sometimes obovate, margins rarely flat, usually sparsely glandular-punctate, rarely glandular-foveate, middle foliaceous, greenish yellow to green, 4–8-striate; third series 9–10.3 × 5–5.8 mm, generally widely oblong to oblong, rarely ovate, apex obtuse, margins entire or pauciserrate, green, apex slightly generally revolute or revolute, rarely flat, apex sparsely glandular-punctate, middle foliaceous, greenish yellow to green, 6–10-striate, generally inconspicuously striate, sometimes conspicuously; innermost series of phyllaries apex rounded, margins entire, thin, flat, apex erose, sparsely glandular-punctate, conspicuously striate; fourth series 9.4–10.5 × 5.3–7.1 mm, oblong to obovate, apex acuminate, generally scarious, sometimes apex foliaceous, usually greenish yellow to yellow, sometimes apex green, 10–15-striate; fifty series 9.8–11.5 × 3.5–4.8 mm, oblong to oblanceolate, scarious, greenish yellow to yellow, 10–12-striate. Receptacle slightly convex, holopaleaceous, paleae 7.8–9.1 × 1–2.2 mm long, longer than corolla disc, narrowly oblanceolate or narrowly elliptic, apex long acuminate, concave or conduplicate, light yellow. Ray florets 12–15, pistillate, corolla 15–20.5(–22.3) mm long, liguliform, yellow, tube 3.1–4.3 mm long, limb 11.8–18.5 × 2.4–4.9 mm, generally narrowly oblong, often oblanceolate, apex generally 2–4-lobulate, often obtuse or rounded, 5–6-veined, abaxial surface densely glandular-punctate, adaxial surface glabrous; style branches 0.9–1.6 mm long, linear, yellow. Disc florets 30–50, monoclinous, corolla tubular, yellow, 5–7.1 mm long, tubular, tube 1.5–2.3 mm long, lobes 0.9–1.6 mm long, sparsely glandular-punctate to densely glandular-punctate; anthers 2.7–3.2 mm long, light yellow, anther appendages apically ovate; style branches 0.8–1.4 mm long, linear, yellow. Cypselae 3.3–3.9 mm long, prismatic, nigrescent, ray cypselae 3-angled, disc cypselae 4-angled, generally glabrous to pilose, sometimes glabrous or pilose, ribs usually pilose to densely pilose, sometimes densely hirsute; pappus bitypic, monolength and bilength, free, scales 8–15 (1–3 distinctly longer), mostly 0.6–1.6 mm long, longer 0.9–2.2 mm long, oblanceolate or oblong, longer elliptic, apex commonly obtuse or rounded, sometimes acuminate, margins entire, apex erose. Distribution, habitat and phenology This natural hybrid was only collected five times in Paraná (Fig. 5), being the taxon with the lowest number of records of Calea subg. Meyeria. This nothospecies grows in Atlantic Forest grasslands in riverine vegetation, but not in moist sites. Calea × malmeana nothosp. nov. flowers and fruits from January to May. Informal conservation status Critically Endangered (CR) B2ab(iii); C; D. While hybrids are typically not evaluated for conservation status, this nothospecies has been documented over a 100-year period, suggesting it represents a recurrent or stable hybrid taxon. The species has an EOO of 824 km ² and an AOO of 16 km ². Due to its hybrid nature, conservation of this nothospecies requires protection of both the hybrid individuals and their parent species populations, compounding the conservation challenges. The populations are severely fragmented (B condition a), and there is a continuing decline inferred in habitat quality (B condition b), with threats similar to those affecting other grassland species in the region. In the most recent record of nothospecies in nature, botanists estimate having seen fewer than 50 mature individuals (R.T. Dall'Agnol, pers. com.). Thus, we propose that this nothospecies should be considered Critically Endangered. Remarks Malme (1933) was the first to record the hybrid nature of Calea × malmeana nothosp. nov., but as previously mentioned, he did not formally describe it. We studied the specimens suggested by Malme (1933), as well as others that we added here and concluded that these specimens are indeed from a nothospecies that co-occurs with its parental species. This new nothospecies can be differentiated from the parental species by different characters that will be explained below. This nothospecies is distinct from C. marginata by glandular-punctate stems and peduncle (vs non-glandular), reticulodromous venation leaf (vs acrodromous basal); first series of phyllaries with obtuse apex (vs rounded or truncate); disc floret corolla glandular-punctate (vs glabrous), and commonly longer cypselae 3.3–3.9 mm long (2.3–3.4 mm). Calea × malmeana nothosp. nov. can be distinguished from C. parvifolia by inconspicuous secondary venation leaf (vs conspicuous), white margin leaf and of outermost series of phyllaries (vs green); first series of phyllaries with obtuse apex (vs acute), and slightly revolute apex (vs flat).