Calea grandiflora V.R.Bueno & G.Heiden, 2023

Bueno, Vinicius R., Cassol, A. P. V., Leroy, C. J., Bueno, M. L. & Heiden, Gustavo, 2023, Two noteworthy Calea (Asteraceae: Neurolaeneae) from contact areas of the Atlantic Forest and Cerrado of Brazil, Phytotaxa 579 (3), pp. 143-161 : 145-149

Calea grandiflora V.R.Bueno & G.Heiden , sp. nov. ( Fig.1 )

Type :— BRAZIL. S „o Paulo , Santo André , Paranapiacaba Biological Station, about 30 km north of Santos, 02 December 1977, L. R. Landrum 2761 (holotype: SP!) .

Calea grandiflora resembles C. arachnoidea but differs by the basal acrodromous venation (vs. semicraspedodromous), outer phyllaries 12.2–20 × 4.2–10.6 mm long (9–12 × 3–5 mm), ray floret corolla 16.9–31 mm long (vs. 10–12 mm), and monolength pappus scales (vs. polylength).

Shrubs, 0.5–2 m tall, stems castaneous, cylindrical, striate, glabrous to puberulous or sparsely sericeous, internodes 9.1–34.5 mm long. Leaves decussate, petiole 2.2–4.3 mm long; blades discolorous, abaxial surface olivaceous, adaxial surface dark green, coriaceous, 1.58–6.86 × 0.84–2.63 cm, elliptic or narrow elliptic, sometimes narrow ovate, base attenuate, apex acute, sometimes attenuate, venation basal acrodromous, margins slightly revolute or revolute, entire or pauciserrate, 0–9 teeth, 0.1–0.8 (–1.1) mm long, from the middle to apex, abaxial surface sparsely glandular-punctate, veins glabrous, adaxial surface glabrous, glands absent. Capitulescence cymose dichasial, slightly branched, axis 0–25.57 cm long, branching to 2 nd order ramifications, 2–8 secondary stems; peduncle 1.35–4.28 cm long, puberulous to pilose or pilose, glandular-punctate to densely glandular-punctate. Capitulum heterogamous, radiate, involucrum campanulate, 8.9–14.65 × 12.44–15.46 mm, 5-seriate; phyllaries conspicuously striated; two outermost series of phyllaries olivaceous, foliaceous, margins entire, flat; first series 5–8 striate, blades 12.2–20 × 4.2–10.6 mm, narrow elliptic to wide elliptic or wide ovate, apex acute or obtuse, abaxial surface glabrous or sparsely puberulous to glabrous, wholly glandular-punctate or only at apex; second series 8–12 striate, blades 13–18.1 × 6.1–7.8 mm, elliptic, apex acute or cuneate, abaxial surface glabrous to sparsely puberulous, sparsely glandular-punctate; third series yellowish green to olivaceous, foliaceous or scarious at apex, blades 10–13.8 × 4.5–8.1 mm, wide elliptic or narrow ovate or ovate to oblong, margins entire, apex obtuse or acute, revolute or flat, abaxial surface glabrous, glandular-punctate at apex; innermost series yellowish green to light yellow, scarious, 9–12 striate, margins entire, abaxial surface glabrous, fourth series blades 7–12.7 × 4.3–5.9 mm, oblong to elliptic, sometimes ovate, apex obtuse; fifth series blades 8.4–14.5 × 4.3–5.9 mm, obovate or elliptic, apex rounded, sometimes obtuse; receptacle slightly convex, holopaleaceous; paleae light yellow, conduplicate, 7.7–9.8 mm long, narrow elliptic, apex acute or long acuminate. Ray florets 10–18, 19–33.2 mm long, pistillate, corolla liguliform, 16.9–31 mm long, yellow, tube 4–5 mm long, limb 12.9–26 × 3.2–3.5 mm, narrow oblong, sometimes narrow obovate, apex 3-lobulate or rounded or obtuse or bifid, 5–8 veins, surface abaxial glandular-punctate, surface adaxial glabrous; style arms yellow, 0.5–1.1 mm long. Disc florets 45–50, 7.8–8.5 mm long, bisexual, corolla tubular, 5.9–6.5 mm long, yellow, tube 1.6–2.2 mm long, lobes 1.4–1.5 mm long, glabrous; anthers light yellow, 2.1–2.9 mm long, apical anther appendages ovate; style arms yellow, 1–1.1 mm long, linear. Cypselae blackish, 2.5–3.2 mm long, prismatic, ray cypselae 3-angled, disc cypselae 4-angled, glabrous, ribs sparsely pilose; pappus monotypic, scales monolength, 10–12, free, 0.9–1.5 mm long, oblanceolate, sometimes oblong, apex obtuse, sometimes rounded, margins entire.

Distribution, Habitat and Predicted Area of Occurrence:— Calea grandiflora occurs in two municipalities from S„o Paulo state and the occurrence points are 50 km away. Probably, it occurs in other hilltops of the Serra do Mar mountain range ( Fig. 2 ), displaying similar environmental conditions. The new species occurs on rocks outcrops amidst the dominant Atlantic Rainforest ( Aguiar et al. 2003), characterized by the high elevation tropical grasslands which harbor distinct floras within the main surrounding vegetation matrix and bears strong past floristic connections with the cerrado (tropical savanna) and campos rupestres floras (high altitude tropical grasslands) typical of Brazilian hinterland mountains (Stafford 2001, Simon 2009).

According to the predicted area of occurrence ( Fig. 3 ), the new species has higher suitability in Serra do Mar mountains from S„o Paulo, where it occurs, and other scattered spots: Itatiaia National Park in the triple border of the states of Minas Gerais, Rio de Janeiro, and S„o Paulo; Lagamar de Cananeia State Park and Guaraqueçaba Ambiental Protection Area at the border of the states of S„o Paulo and Paraná; the area nearby Campos do Quiriri, S„o Joaquim National Park highlands and the coastal promontory of Serra do Tabuleiro State Park in the state of Santa Catarina; the Aparados da Serra highlands escarpment area of Serra Geral close to the ocean in northeastern Rio Grande do Sul. Although all the modeled area is not likely occupied by C. grandiflora due the land discontinuity of the sky island distribution of rock outcrops on mountaintops, for example, in the flora of Itatiaia (Moreira et al. 2021) this species was not found. Our modeling shows that these areas bear suitable habitats for the new species and could harbor other Calea species with habitat requirements similar to those of C. grandiflora . Besides C. grandiflora , only C. subintegerrima ( Malme 1933: 94) V.R.Bueno & G.Heiden ( Bueno & Heiden 2022a) and C. ilienii Malme (1933: 94–95) , from the C. myrtifolia complex, have occurrence records along the Serra do Mar range.

Informal Conservation Status:— Calea grandiflora could be considered Critically Endangered (CR). The analyses through GeoCAT ( Bachman et al. 2011) generated only an AOO (8.0 km²), due the limited distribution records known so far (only two points). According to the IUCN (2019) criteria, this new species complies with several requirements of the CR status: B1B2; C2(i); D, mainly because the new species was found in only two locations. The scarce records, in agreement with the condition ba ( IUCN 2019), suggest that this species is Endangered. Despite the apparent contradiction, when two distinct statuses are confronted, the most restrictive one is preferred according to the IUCN (2019) guidelines.

Calea grandiflora occurs in two protected areas: Paranapiacaba Biological Station and Sabesp Forest Reserve. These areas are in one of the four centers of endemism of the Atlantic Forest ( Aguiar et al. 2003). Due to the apparent rarity, the AOO value, the adopted IUCN criteria and conditions, and because the last collection is from 1991, the status CR is warranted for C. grandiflora .

Etymology:—The epithet “grandiflora” refers to the ray florets, which are larger than those found in other species of the Calea myrtifolia complex.

Phenology: —The collected specimens were flowering and fruiting in December and March.

Taxonomic comments: —One of the two specimens of Calea grandiflora was initially identified as C. myrtifolia , probably due to the glabrous leaves, acrodromous venation, and involucrum with foliaceous outer phyllaries. These features together with shrubby habit, cymose dichasial capitulescence, and the pappus shorter than the cypsela place it in the Calea myrtifolia complex. These two species can be distinguished by elliptic blade leaf (vs. ovate or lanceolate), attenuate base leaf (vs. rounded), outer series of phyllaries 12.2–20 mm long (vs. 4.9–11.3 mm), ray floret tube 4–5 mm long (vs. 2.1–3.1 mm), disc corolla lobes 1.4–1.5 mm long (vs. 0.8–1.2 mm).

The elliptic and longer leaves, the capitulum with longer outer phyllaries and ray floret corolla, and the uncommon occurrence in the Serra do Mar corroborate that this is a new species, resembling the previously described Calea arachnoidea Reis-Silva & Nakajima (2021: 130–131) .

Both Calea grandiflora and C. arachnoidea have shrubby habit, elliptic leaves up to 6.8 cm long, slightly branched cymose dichasial capitulescence, glandular-punctate peduncle, involucrum 10.8–20 mm long, and similar habitat associated with rock outcrops in the Atlantic Rainforest. These species can be differentiated by the striate stems (vs. conspicuously furrowed), discolorous leaf blades (vs. concolorous), venation basal (vs. semicraspedodromous); peduncle 1.35–4.28 cm long (vs. 0.3–0.8 cm), puberulous to pilose or pilose indumentum (vs. arachnoid, rarely glabrous), outer series of phyllaries 12.2–20 × 4.2–10.6 mm long (9–14.1 × 2.9–6.1 mm); paleae 7.7–9.8 mm long (9.8–13.2 mm); ray florets 10–18 (vs. 3–8), corolla 16.9–31 mm long (vs. 8.1–12 mm); and monolength pappus scales (vs. polylength).

Paratype: — BRAZIL. SÃO PAULO: Salesópólis, Reserva Florestal da Sabesp, adjacente à Estaç„o Biológica da Boraceia , 22 March 1991, M. Kirizawa 2432 (SP) .

Figures

FIGURE 1. Calea grandiflora sp. nov. (Neurolaeneae, Asteraceae) A. Flowering branch. B. Leaf with pauciserrate margins, adaxial surface. C. Margin with small teeth. D. Abaxial surface indumentum. E. Phyllary of first series. F. Phyllary of second series. G. Phyllary of third series. H. Phyllary of fourth series. I. Phyllary of fifth series. J. Striate surface of scarious phyllaries. K. Capitulum with ray florets removed to show involucre, paleae and disc floret arrangements. L. Ray floret. M. Disc floret with monolength pappus scales. N. Cypsela with monolength pappus scales.A–N drawn from L. R. Landrum 2761 (SP); A–M: millimeter scale. Illustration by Débora Dalzotto.

FIGURE 2. Occurrence map of Calea grandiflora, C. parvifolia, C. × parviantha, and C. triantha (Neurolaeneae, Asteraceae) in Brazil. MG—Minas Gerais, SP—S„o Paulo, PR—Paraná, SC—Santa Catarina. Figure by: Marcelo L. Bueno.

FIGURE 3. Prediction occurrence map of suitable ecological niche modelling for Calea grandiflora and C. × parviantha (Neurolaeneae, Asteraceae). Figure by: Marcelo L. Bueno.