Miconia pachyphylla Cogn.

Bécquer, Eldis R., Bochorny, Thuane, Gavrutenko, Maria & Michelangeli, Fabián A., 2022, A revision of the “ basal-axile placentation clade ” of Miconieae, the newly erected Miconia sect. Liogieria (Melastomataceae: Miconieae) from the Greater Antilles, Willdenowia 52 (3), pp. 387-432 : 415-418

9. Miconia pachyphylla Cogn. in Jahrb. Konigl. Bot. Gart. Berlin 4: 279. 1886 ≡ Acinodendron pachyphyllum (Cogn.) Kuntze, Revis. Gen. Pl. 2: 952. 1891. – Lectotype (designated here): Puerto Rico, Sylva de Luquillo, in sylvis primaeva ultra planicium montis Jimenez, 9 Jul 1885, Sintenis 1334 ( BR 5212255 [photo!]; isolectotypes: BR 5212316 [photo!], GH 72762 !, GOET 8010 [photo!], K 535912 !, LD 1423560 [photo!], M 165631 [photo!], S 5-3638 [photo!], US 00120809!, US 00594710!). – Fig. 2D, J; 3D, E; 17.

Morphological description — Shrubs or small trees to 10 m tall, branched, evergreen. Indumentum of appressed and matted lanate trichomes 0.3–0.4 mm long, ferruginous on young branches, leaves, inflorescences, flowers and hypanthium, and sessile to shortly stalked glandular trichomes c. 0.1 mm long, reddish, on young leaf surfaces. Young branches terete, slightly flattened, densely lanate. Mature branches with reddish to grey fissured bark. Petiole 1–3 cm long, terete, densely lanate; leaf blade 6–17 × 3.3–8 cm, ovate-lanceolate, coriaceous, base cordate to subcordate, apex attenuate to acuminate or acute, rarely obtuse, margin revolute, entire; adaxial surface flat, lanate when young, later glabrescent; abaxial surface densely reddish to brown lanate mostly at veins, later glabrescent except on veins. Venation with 2 pairs of secondary veins, symmetric, basal; midvein and secondary veins impressed adaxially and prominent abaxially, tertiary veins slightly impressed adaxially and prominent abaxially, quaternary veins visible adaxially and slightly impressed abaxially. Mite domatia absent. Inflorescence 5–11.5 × 4–11.5 cm, a pyramidal paniculate cyme, peduncle 1–4.5 cm long, with 9–100 flowers; each inflorescence with 2–4 pairs of branches, pseudopedicel 0.2–0.5 mm long; bracts 0.02–1.2 cm long, subulate, persistent, bracteoles 0.5–0.7 mm long, subulate persistent. Flowers 4-merous, sessile or with pedicel c. 1 mm long. Hypanthium c. 2.4 × 2.1 mm, campanulate, free portion c. 0.5 mm long, external surface tuberculate and puberulous with appressed and matted trichomes, internal surface glabrous. Calyx tube c. 1 mm long; calyx lobes inconspicuous, broadly triangular to truncate, c. 0.1 mm long, internal surface glabrous; calyx teeth inconspicuous, tuberculate, c. 0.1 mm long. Petals 3.5–4 × c. 2 mm, oblong, symmetric, purple, glabrous, base slightly decurrent, apex rounded to truncate with an apical notch. Stamens 8, deflexed to opposite side of flower to style. Filaments 1.8–2 × c. 0.3 mm, flattened, distally attenuate and geniculate, white. Anthers c. 1.5 × 0.5–0.6 mm, ovate to oblong, obtuse; connective projecting below thecae 0.4–0.5 mm; thecae smooth, with an apical pore. Ovary 3-locular, free portion rounded to conic, apex deeply depressed at insertion of style, forming a ring around style, glabrous; placentation axile-central. Style c. 4.2 mm long. Berries 5–6 mm long, globose, 40–50-seeded. Seeds 1.3– 1.7 mm long.

Phenology — Flowering specimens have been collected from January to May, fruiting specimens in March and from May to August.

Distribution and ecology — Miconia pachyphylla is endemic to Puerto Rico ( Fig. 18). It grows in montane thickets, dwarf forests and moist forests at 300–1060 m in El Yunque massif and Barrio Farrallón in the E portion of the island.

Informal conservation status — Miconia pachyphylla has an estimated EOO of 115 km 2 (within the limit for Endangered status under sub-criterion B1) and its AOO is estimated at 10 km 2 (also within the limit for Endangered under sub-criterion B2). It is known from 20 localities representing two locations (sensu IUCN 2012). We have no data to estimate the size of the population, although the species is considered rare. The populations are not considered severely fragmented, and one location is included in El Yunque National Park. Most of the habitat of this species is considered conserved, but the location of Barrio Farrallón SW of El Yunque is threatened by agriculture and livestock, deforestation and invasion of exotic species. Therefore, there is a decline in extent and quality of habitat, resulting in a potential decline in EOO and AOO. If we take into account the number of locations, fewer than five, it is possible to assess M. pachyphylla as Endangered under criteria B1ab(i,ii,iii,iv,v)+2ab(i,ii, iii,iv,v).

Discussion — The relationships between Miconia pachyphylla and the remaining species of the clade are not clear; the indumentum most closely resembles that of M. baracoana , M. monocephala and M. yamanigueyensis , but the lanate trichomes have appressed arms and are matted. On the other hand, the inflorescences of M. pachyphylla are pyramidal-paniculate cymes (vs dichasia, capitate glomerules, corymbiform cymes or basally branched lax paniculate cymes in the rest of the species).

The protologue of Miconia pachyphylla ( Cogniaux 1886) mentioned two gatherings, Sintenis 1334 and Sintenis 1566, which therefore must be considered syntypes ( Turland & al. 2018: Art. 9.6). Further, Cogniaux did not mention the herbarium where these gatherings were deposited. In BR, the herbarium in which Cogniaux worked ( Stafleu & Cowan 1976; Stafleu & Mennega 1997), there are two specimens of Sintenis 1334 and one of Sintenis 1566. The specimen BR 521225 belonging to Sintenis 1334 also includes a description of the species on the label with the handwriting of Alfred Cogniaux, and is therefore selected as the lectotype.