Miconia bucherae Alain

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 : 404-407

= Miconia bucherae Alain in Contr. Ocas. Mus. Hist.

Nat. Colegio “De La Salle” 14: 2. 1955. – Holotype:

Cuba, Prov. Oriente [HolguÍn], Moa , Dec 1939, G. C .

Bucher 124 ( NY 99516 !; isotype: HAC ex SV 11441 !) .

Morphological description — Shrubs 1–2 m tall, deciduous. Indumentum of stellate and dendritic trichomes 0.1– 0.2 mm long, brown to ferruginous on young branches, leaves, inflorescences, flowers and fruits, and elongate glandular trichomes c. 0.5 mm long on very young leaves. Young branches squared, with lenticels, at first densely tomentose, later glabrescent. Mature branches with light brown bark and conspicuous longitudinal lenticels. Petiole 4–7 mm long, terete, canaliculate adaxially, densely tomentose, later glabrescent; leaf blade 2–3 × 0.6–1.1 cm, oblong-lanceolate to elliptic-lanceolate, subcoriaceous, base rounded to cuneate, apex acute, margin revolute, entire, sometimes glandular ciliate on very young leaves, lat- er becoming glabrous; adaxial surface flat to bullate, glabrescent, wrinkled when dry, darker than abaxial surface; abaxial surface tomentose, later sparsely tomentose, indumentum confined to veins, epidermis drying distinctly brown-yellowish. Venation with 1 pair of secondary veins, symmetric, conspicuous, basal to slightly suprabasal, placed c. 1 mm above base; midvein and secondary veins impressed adaxially and prominent abaxially, tertiary veins slightly impressed adaxially and prominent abaxially, quaternary veins mostly inconspicuous to prominent abaxially. Mite domatia absent. Inflorescence 1–3.5 × 1–3.5 cm, peduncle c. 1.5 cm long, with 1–3 flowers; each inflorescence with 1 pair of branches, pseudopedicel 3–5.5 cm long; bracts c. 2 mm long, linear, early caducous, bracteoles c. 1 mm long, linear-subulate, early caducous. Flowers 4- or 5-merous; pedicel 0.5–1 mm long. Hypanthium c. 2.5 mm long, campanulate, free portion c. 1 mm long, external surface sparsely tomentose, internal surface glabrous. Calyx tube c. 0.3 mm long; calyx lobes c. 0.6 mm long, broadly triangular, internal surface glabrous; calyx teeth c. 0.5 mm long. Petals c. 6 × 3.5 mm, obovate, white with pink tint, glabrous, base decurrent, apex obtuse with a lateral notch. Stamens 10, deflexed in 2 groups on both sides of flower at anthesis, (1–)3 or 4 on same side as style and 6 or 7(–9) on opposite side, or deflexed as 1 group opposite style, rarely surrounding style; filaments later deflexed backward and all stamens turning pink to red with age, mostly falling together with petals. Filaments c. 5 mm long. Anthers c. 3 × 1 mm, lanceolate, connective projecting 0.1–0.2 mm long below thecae; thecae smooth, with an apical pore, white. Ovary 2-locular, free portion rounded, apex lobulate, glabrous; placentation axile-basal. Style c. 5 mm long. Berries c. 4 × 4 mm, c. 20-seeded. Seeds c. 2 mm long.

Phenology — Flowering specimens have been collected in May, fruiting specimens in January.

Distribution and ecology — Miconia lenticellata is endemic to E Cuba ( Fig. 11), where it occurs in the Sierra de Nipe, Sierra de Moa, coastal area of Moa (HolguÍn) and the Sierra del Frijol (Guantánamo). It grows in semi-arid montane serpentine shrub woods ( Borhidi 1996) at 10– 995 m.

Informal conservation status — Miconia lenticellata was assessed in the Red List of Cuban flora as a Data Deficient (DD), and its synonym M. bucherae was preliminarily assessed as Threatened, but without a specific category (see González-Torres & al. 2016). The EOO of M. lenticellata is estimated to be 283 km 2 (within the limit for Endangered status under sub-criterion B1) and its AOO to be 6 km 2 (within the limit for Critically Endangered under sub-criterion B2). It is known from six localities, all except one of which are inside protected areas (National Parks Alejandro de Humboldt and Mensura-Pilotos and Protected Area with sustainable use of natural resources Cuchillas del Toa). Intentional fires, civil constructions, logging of associated species and pollution represent the main threats to its habitat. A decline in extent and quality of habitat is expected in part of its range (Moa, Yamaniguey and Loma la Bandera, Sierra de Nipe). The six localities represent five locations sensu IUCN (2012). The species is considered very rare; in three localities only three mature individuals have been observed, so it could be estimated that the population of this species has fewer than 50 mature individuals, falling within the limit for Critically Endangered status under criterion D. It can also be considered as a severely fragmented population due to the small number of individuals, which makes gene flow between its localities unlikely, especially between the Sierra de Nipe and Sierra de Moa. Therefore, we recommend that M. lenticellata be considered Critically Endangered (CR) B2ab(iii,v); D.

Discussion — Miconia lenticellata can be distinguished from the other members of M. sect. Liogieria with the leaf abaxial surface visible and not obscured by the indumentum (i.e. M. cerasiflora , M. lutgardae , M. obtusa , M. pachyphylla , M. thomasiana and M. victorinii ) by its mature leaves persistently ± densely stellate tomentose (vs mature leaf with abaxial surface glabrescent or the indumentum very sparse or confined to the veins).

Alain described Miconia lenticellata and M. bucherae in the same publication ( Alain 1955). He differentiated them by floral merosity (5-merous in M. lenticellata and 4-merous in M. bucherae ), and by the somewhat larger leaves in M. lenticellata . Additionally, he stated that M. bucherae was unique among Cuban Melastomataceae due to its leaf size and shape. He placed M. bucherae near M. obtusa but distinguished it from the latter by the pubescence on the abaxial surfaces of the leaves. The descriptions in the protologues were based on only one gathering per species, thereby not allowing Alain to appreciate the full variability in this group; in the case of M. lenticellata the type has only fruits and in the case of M. bucherae the type has only flowers ( Alain 1955). Recent collections of this entity have vegetative characters that resemble the type of M. lenticellata , but with 4-merous flowers as in the type of M. bucherae . Although floral merosity has been used as a distinguishing character in some species complexes of Miconieae ( Michelangeli 2005) , it is usually accompanied by other co-occurring characters. Moreover, floral merosity has been found to vary occasionally even within the same individual, and discounting this character has already led to the synonymization of other names in the Miconieae (e.g. Pachyanthus clementis P. Wilson ex Britton and P. lunanus Britton & P. Wilson , currently accepted as M. clementis (P. Wilson ex Britton) Bécquer ; Bécquer 2012). Therefore, we believe that M. lenticellata and M. bucherae are indeed the same species, and we choose to keep the name M. lenticellata because the great majority of the collections of this species have been determined under this name.

The protologue of Miconia lenticellata (Alain 1955) mentioned that the type was deposited in the Colegio de La Salle herbarium (LS) and that there was an isotype in NY. The herbaria formerly in LS and SV are now housed in the herbarium HAC ( Regalado Gabancho & al. 2010). There are two specimens of Alain 3746 in HAC, one of which is clearly that from LS because it is labelled as such and it corresponds to the one in the protologue ( Alain 1955: fig. 3); it should therefore be considered as the holotype and the one from SV as an additional isotype.