Miconia waimiri-atroari Meirelles & Caddah, 2021

Meirelles, Julia, Sartor, Mariana Furlan, Chagas, Rennan Lopes & Caddah, Mayara Krasinski, 2021, Miconia waimiri-atroari (Miconieae, Melastomataceae): a new species from the Brazilian Amazon Forest, Phytotaxa 521 (3), pp. 203-211 : 204-209

Miconia waimiri-atroari Meirelles & Caddah , sp. nov. Figure 1–3 (A–B).

Diagnosis: — Miconia waimiri-atroari differs from other Miconia species by the following set of characters: cylindrical young branches, 3-nerved leaves with abaxial surface covered by stellate trichomes, inflorescences with scorpioid branches, triangular, glabrous, persistent calyx lobes, glandular-ciliate petals, antesepalous stamen connectives with glandular trichomes, stamens with yellow filaments that turn red when older, and glandulate styles.

Type: — BRAZIL, Amazonas : Presidente Figueiredo, Área do Reservatório de Balbina, 1°30’– 2°00’S, 59°30’– 60°00’W, fl. 20 Sep 1986, Cid Ferreira et al. 8222 (Holotype: INPA!; Isotypes: CAS, MG!, MO, NY!) .

Description: —Shrub or treelets 3–8 m tall. Branches cylindrical, densely covered by stellate, flat trichomes, with interpetiolar lines between the bases of the petioles. Petiole 0.9–3.0 cm long, quadrangular, slightly sulcate; blade 10.8–18 × 4–7.5 cm, oblong, papyraceous, base round to obtuse or slightly acute, margin entire to slightly revolute, not ciliate, apex attenuate to acuminate, 3-nerved, with one pair of secondary veins originating at the base of the blade and running close to the base marginal region (4–10 mm apart the margin, from basal to the medial portion of leave), plus an additional, thinner, submarginal pair, veins impressed on the adaxial surface and prominent in the abaxial surface of the leaves, without mite domatia, tertiary veins disposed in a straight angle (close to 90° degrees) to the midrib; adaxial surface glabrous, abaxial surface densely covered by stellate, flat trichomes, 0.03–0.04 mm diam. Inflorescence 5.5– 15.2 cm long, branches bifid, scorpioid, with up to 4 flowers per branch; bracts 0.5–4 × 0.4–0.9 mm, narrow triangular to linear, margin entire, not ciliate, apex acute, adaxial surface glabrous, abaxial surface furfuraceous and densely covered by stellate, flat trichomes, persistent; bracteoles up to 0.3 × 0.4 mm, lanceolate, margin entire, not ciliate, apex acute, adaxial surface glabrous, abaxial surface furfuraceous and densely covered by stellate, flat trichomes, persistent. Flowers 5-merous, sessile, hypanthium 1.5–2 × 1–1.5 mm, campanulate, costate, externally furfuraceous and densely covered by stellate, flat trichomes; calyx persistent, tube 0.15–0.3 mm long, lobes 0.4–0.6 mm long, triangular, inner surface glabrous, externally covered as the hypanthium, calyx teeth exceeding the lobe apex up to 0.02 mm, externally covered as the hypanthium; petals 3–3.5 × 1.3–1.6 mm, obovate to oblong, deflexed, white, margin glandular-ciliate; stamens 10, dimorphic; antesepalous filaments 4–4.5 mm long, anthers 3.6–5 mm long, yellow, connective 0.7–1.2 mm long, dorsally prolonged, with (1–)2(–3) pairs of subsessile glandular trichomes in the ventral surface, ca. 0.03 mm diam.; antepetalous filaments 2.5–3.3 mm long, anthers 2.1–2.5 mm long, yellow, connective 0.7–0.8 mm long, dorsally prolonged, without trichomes; both cycle with yellow filaments, turning red with age. Style 6.7–10 mm long, curved at the apex, the proximal half sparsely covered with glandular-stipitate trichomes, ca. 0,1 mm long, distal half glabrous, stigma punctiform to truncate; ovary 1.1 × 0.6 mm, 2/3 inferior, papillose at the apex, 3-locular. Fruits baccate, up to 4.2 × 5 mm, round, costate, purple. Seeds 1.4–1.9 mm long, pyramidal.

Distribution and habitat: — Miconia waimiri-atroari is only known from the state of Amazonas, Brazil, in areas of Campinarana and Terra-Firme forest, north of Manaus ( Figure 4 ).

Phenology: —The new species was collected with flowers from June to September and with fruits from August to September.

Etymology: —The new species is named after the indigenous people of Waimiri-Atroari, whose territory is located near the BR-174, between Manaus (Amazonas) and Boa Vista (Roraima), where the species occurs. During the construction of the BR-174, mainly in the 1960’ and 1970’s, these people have suffered a massive genocide by the military government of that time, and lost part of their land to farmers, squatters and the state ( Sousa et al. 2020). Besides the BR-174, the Balbina Dam and mining companies have also explored the land of the Waimiri-Atroari, contributing to population decrease from 3000 in 1972 to 350 people in 1983 ( Damasio 2019). The epithet is a name in apposition.

Conservation Status: —At the moment, the new species is only known from a few collections around Manaus, in Amazonas, Brazil. Miconia waimiri-atroari has the extension of occurrence (EOO) of 11,747 km ², and 24 km ² as area of occupancy, what would suggest a vulnerable (VU) or endangered (EN) category ( IUCN 2019). It is not possible yet to infer severe population decline, despite the current devastation suffered by the forest. Therefore, we recommend that the species be classified as Data Deficient. Some collections were made in natural reserves (see below). However, considering its limited occurrence, we consider that the species is a priority for data gathering.

Additional Specimens Examined: — BRAZIL. Amazonas : Itapiranga , Campina dos Padres, 3 hours by boat south of Represa Balbina, 2°15’S, 59°00’W, 11 July 1986, Thomas et al. 5466 ( INPA!, MO, NY!, US) . Manaus , Reserva Biológica do INPA, Rodovia Manaus-Caracaraí, Km 62, 13 August 1975, Anderson 120 ( NY!, US), Anderson 164 ( INPA, NY!) ; Reserva Biológica de Campinas , 31 August 1976, Carreira 142 ( INPA!) ; RDS do Tupé , Campinarana próximo a comunidade Agrovila, 2°58’55”S, 60°14’26”W, 09 June 2013, Demarchi & Moura 347 ( INPA!) , Demarchi 348 ( INPA) , 28 September 2013, Demarchi 349 ( INPA!) ; Rio Cuieras , 11 September 1973, Prance et al. 17717 ( INPA!, MO, US!), 13 September 1973, Prance et al. 17879 ( INPA!, MG!, MO, NY!) ; Estrada Manaus-Caracaraí , Reserva Experimental de Silvicultura Tropical, 16 September 1977, Ribamar & Ramos 254 ( INPA) ; Cachoeira Baixa de Tarumã , 30 August 1962, Rodrigues & Chagas 4614 ( INPA!, US!) ; Reserva Ducke , Igarapé do Acará, 15 October 1994, Sothers 199 ( INPA!, MG!, MO) . Presidente Figueiredo , Estrada Manaus-Caracaraí (BR-174), Estrada para Balbina Km 69, próximo às obras, 8 August 1979, C id Ferreira et al. 56 ( NY!) . São Sebastião do Uatumã , RDS Uatumã, parcelas do PELD-MAUA e arredores, 07 September 2018, Demarchi 1336 ( INPA) , 07 November 2018, Demarchi 1416 ( INPA) , 10 October 2019, Demarchi 1595 ( INPA) , 10 November 2019, Demarchi 1611 ( INPA) .

Comments: —Most specimens cited here as Miconia waimiri-atroari were initially determined as M. argyrophylla Candolle (1828: 181) . Both species share discolorous leaf blades, inflorescences with scorpioid branches, petals with glandular-ciliate margins and dimorphic stamens with the antesepalous ones with glandular connectives, and overlapping occurrence area. However, there are some distinct features between them. Possibly, the most remarkable character of the new species is the stamens with yellow filaments that turn red in old flowers. This feature can be found in some species from the Brazilian Cerrado (e. g. M. stenostachya Candolle [1828: 181] and M. fallax Candolle [1828: 181] ), but are not reported for any other species in the area Miconia waimiri-atroari is found. Miconia argyrophylla , as all other species from Amazon mentioned below, have white stamens that only become pale in old flowers (but yellow stamens in M. astrocalyx Meirelles & Goldenberg [2016: 188] from Cerrado). Besides that, M. argyrophylla could be easily distinguished from the new species by the quadrangular young branches; the leaf abaxial surface covered by arachnoid (vermiform) trichomes ( Figure 3 ); and by the completely glabrous style ( Table 1).

Other species that occur in the same region of M. waimiri-atroari and have discolorous leaves, scorpioid inflorescences and dimorphic stamens are M. amnicola Wurdack (1981: 243) , M. dichrophylla Macbride (1929: 189) , M. dispar Bentham (1850: 241) , M. lepidota Candolle (1828: 180) , M. macuxi Meirelles et al. (2015: 56) , and M. punctata ( Desrousseaux 1797: 50) D.Don ex Candolle (1828: 184) . For more information about distinctive features of these species, see Table 1.

Due to the overall resemblance to M. argyrophylla , the glandular flower parts, which are shared with M. macuxi , and the yellow anthers, shared with M. stenostachya and M. fallax , we believe that M. waimiri-atroari is probably phylogenetically related to the Miconia albicans clade (Caddah et al. in prep.). Miconia waimiri-atroari would key out in step 5 of the key of the Albicans clade (Meirelles 2015), close to M. astrocalyx and M. macuxi . Miconia astrocalyx , a species that occurs in Cerrado and Caatinga, also has the abaxial surface of leaves densely covered by stellate trichomes, inflorescence with scorpioid branches, petals with glandular-ciliate margins, yellow anthers and glandular style ( Meirelles 2016). However, it is quite distinctive from M. waimiri-atroari , mainly due to leaf size and morphology (smaller, cordate and crenulate leaves), calyx lobes (longer and internally pilose at the base), stamens (completely glabrous and with filaments not turning red when old) and distribution.

Acknowledgements

J.M. thanks Museu Paraense Emílio Goeldi for grant from the Programa de Capacitação Institucional (PCI); MKC thanks Fernanda Nunes Cabral for field assistance. All authors thank Carlos Alvarez for illustration, the PBI Miconieae project (National Science Foundation, DEB-0818399) for SEM support, Fabián Michelangeli for literature support, Fernanda Maria C. de Oliveira for plate design, Duane F. Lima for map design, Francisco Farroñay and Layon Oreste Demarchi for images of fresh material, and editor and manuscript reviewers. This study was financed in part by the ‘Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico – Brasil (CNPq)’ and by the ‘Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES)’ – Finance Code 001.

Figures

FIGURE 1. Miconia waimiri-atroari. A: Branch with inflorescence. B: Flower. C: Style. D: Antesepalous stamen in lateral view. E: Antepetalous stamen in lateral view. F: Antesepalous stamen in ventral view. G: Petal. H: Fruit in upper view. I: Fruit in lateral view. Drawn by Carlos Alvarez based on the MG isotype.

FIGURE 2. Miconia waimiri-atroari. A: Branch with leaves and inflorescence. Flower in detail, with thin arrow pointing to petal with glandular-ciliate margin, and thick arrows pointing to glandular trichome on antesepalous stamen connective. B: Inflorescence branch with buds and young flowers. C: Inflorescence branch with young and old flowers. D: Young and old flowers. A-B: Photos by Francisco Farroñay, C-D: Photos by Layon Oreste Demarchi.

FIGURE 3. Indument comparison between M. waimiri-atroari and M. argyrophylla under SEM. A-B: M. waimiri-atroari. A: Abaxial surface of the leaf showing midrib and blade tissue with stellate trichomes densely grouped. B: Detail of the individualizable stellate trichomes. C-D: M. argyrophylla. C: Abaxial surface of leaf showing midrib, secondary vein and blade covered by arachnoid trichomes. D: Detail of non-individualizable trichomes.

FIGURE 4. Geographic distribution of Miconia waimiri-atroari, with the state of Amazonas, Brazil.