Pleiochiton amorimii Reginato & R.Goldberg

  • Family

    Melastomataceae (Magnoliophyta)

  • Scientific Name

    Pleiochiton amorimii Reginato & R.Goldberg

  • Primary Citation

    Brittonia 65: 23 (-25, fig. 1 A-F). 2013

  • Type Specimens

    Specimen 1: Isotype -- A. M. Amorim 7024

  • Description

    Description Author and Date: Marcelo Reginato, José Fernando Andrade Baumgratz, and Renato Goldenberg, based on A Taxonomic revision of Pleiochiton (Melastomataceae, Miconieae). Reginato, M., Baumgratz, J.F.A., & Goldenberg, R. Brittonia, 65(1), 2013, pp. 16–41

    Type: Brazil. Bahia: Camacan, “RPPN da Serra Bonita”, 14 Apr 2007, A.M. Amorim 7024, M. M. Lopes, F. B. Matos, W. D. Rocha & S. Vieira (holotype: CEPEC; isotypes: NY, UPCB).

    Description: Young branches, inflorescences and hypanthia sparsely covered by glandular trichomes, 1.5–2 mm long; older branches and leaves glabrous. Old branches 3.5–6 mm diam., nodes 6–15 mm diam. Leaves isophyllous; petioles 2–7 mm long; blade 3–7 x 2–4 cm, ovate or orbicular, chartaceous to coriaceous, apex obtuse, acute to slightly acuminate, base rounded or shortly cordate, margin slightly crenulate and revolute, ciliate (trichomes 1.5–2.5 mm long); acrodromous nerves 5 or 3+2, basal. Cymes 3–7 cm long, terminal or lateral, lax, 3–18-flowered, 1–3 pairs of paraclades plus an apical triad, anthopodia 2–6 mm long; bracts 1.8–2.7 mm long., oblong or lanceolate, entire, glabrous, rarely ciliate; bracteoles 2–3.5 mm long, not involucral. Flowers (4)5-merous, sessile or pedicels 0.3–0.6 mm long. Hypanthium 3.8–4.8 x 2.9–3.8 mm, campanulate, torus glabrous. Calyx tube 0.6–0.9 mm long, lobes 0.5–1.1 mm long, deltoid; external teeth 2.4–3.2 mm long. Petals 4–6.2 x 2.7–3 mm, triangular to ovate-lanceolate, apex acute or acuminate. Stamens slightly unequal in size, the shorter filaments 2.5–3.8 mm long, the longer ones 3–4.6 mm long; anthers cream to whitish, dorsally arcuate, the shorter ones 3.5–4.8 mm long, the longer ones 3.8–5.5 mm long, pore dorsal; connective 0.2–0.8 mm, prolonged below the thecae, unappendaged or with a minute basal lobe. Ovary 1/4–1/3 inferior, 2.7–3 x 1.6–2 mm, tubulose, sometimes slightly attenuate, glabrous; style 7–11 mm long. Fruits and seeds not seen.

    Habitat and Distribution: Pleiochiton amorimii is the only endemic species of the northern part of the Atlantic Forest, in southern Bahia (Fig. 3B), where it is sympatric with the widespread P. blepharodes. All plants were collected in montane forest, on hosts up to 30 m high. Collected with buds in March and with flowers in April and August.

    Phenology: Collected with buds in March and with flowers in April and August.

    Etymology: This species is named after Dr. André M. Amorim, from Universidade Estadual Santa Cruz, BA, curator of the herbarium CEPEC, and leading botanist in southern Bahia, as well the collector of the type specimens.

    Taxonomy and Systematics: Pleiochiton amorimii is recognized by the leaves with 5 main nerves, inflorescences with up to 20 flowers, ratio between external teeth and hypanthium lengths about 0.65, bracteoles oblong, and anthers whitish to cream. The holotype has orbicular leaves, which have not been found elsewhere in the genus. This species is similar to P. ebracteatum, but the latter is different because it has a ratio between the external teeth and hypanthium lengths almost equaling 1, and yellow anthers. Additionally, the bracteoles of P. ebracteatum are ovate to lanceolate, while in P. amorimii they are usually oblong. The leaves in P. ebracteatum have 3+2 acrodromous nerves, while in P. amorimii they are mostly 5-nerved.

  • Sorry, no descriptions available for this record.