Miconia cinnabarina Jan.M.Burke & Michelang., 2018

Burke, Janelle M. & Michelangeli, Fabian A., 2018, Six new species of Miconia (Miconieae, Melastomataceae) from the Andes, Phytotaxa 361 (2), pp. 131-150 : 138-139

Miconia cinnabarina Jan.M.Burke & Michelang. , sp. nov. ( Fig. 4 )

Diagnosis: Similar to other species of Miconia sect. Amblyarrhena , with anthers tapering to minute pore, but can be distinguished by bifacially flattened inflorescence axis and distinctive, deep red hypanthia, and conspicuous calyx teeth.

Type:— BOLIVIA. Cochabamba: Prov. Chapare, El Limbo, 2200 m, 27 November 1966 (fl), Steinbach 548 (holotype: NY!; isotypes: RSA!, US!) .

Tree, 6.5–8 m tall. Young stems obscurely bifacially flattened, mature stems terete, glabrous, internodes with irregular longitudinal fissures, nodal line absent. Leaves isophyllous; petiole 5.9–12.3 cm long, the indumentum of sparse sessile pigmented glands; the blade 7.1–9.6 × 2.1–3.1 cm, oblong elliptical to elliptical, membranaceous, the apex long acuminate (0.6–1.2 mm), the base attenuate, the margin inconspicuously serrate, teeth 0.25 mm; secondary veins 2 pairs, basally nerved to plinerved, diverging 0–0.5 cm above the base, mostly symmetrical, faint marginal veins present, tertiary veins percurrent, faint, reticulate, veins impressed on the adaxial surface and raised, red on the abaxial surface; adaxial surface dark green, the indumentum on the surface glabrous, and glabrous on the primary and secondary veins; abaxial surface green, the indumentum consisting of a few sessile glands and sparse sessile, translucent dendritic hairs; pocket domatia at confluence of secondary veins, less than 0.5 cm deep. Inflorescences terminal, lax panicles of cymose units, 7.3–8.5 cm long; peduncles bifacially flattened, brown or red, the indumentum glabrous to scabrous; bracts and bracetoles not seen. Flowers 5-merous, bisexual; the pedicel 0.5–0.75 mm long. Hypanthium 2–2.5 mm long, campanulate, 2.8–3.7 mm wide at the torus, external indumentum of sessile translucent glands, internal surface glabrous, androecial fringe absent. Calyx open in bud, the tube 0.3–0.4 mm long at anthesis, the lobes 1 × 0.8 mm, acutely deltoid, apex densely pubescent with stellate hairs, drying yellow; calyx teeth acutely deltoid, 1.2–1.5 × 0.8 mm, as calyx lobes, green or red. Petals 2.3–2.5 × 2 mm, ovate, spreading to reflexed, pale yellow at anthesis (drying pale yellow), granulose on adaxial surface, the apex retuse, the base obtuse, the margin entire. Stamens diplostemenous, isomorphic, either actinomorphic, or deflexed away from style at anthesis; filament 2.3–2.4 mm long, glabrous, yellow, anthers with 2 locules, thecae 1.5–1.8 × 0.5–0.6 mm, cuneate, tapering apically, opening by 1 dorsally inclined, 0.2 mm pore, yellow at anthesis, later turning red, connective not extended below thecae. Ovary 5-locular, 1/3 free, the free portion projecting 0.4 × 1.2 mm, hemispherical, the apex wihtout a corona; the style 4.7–5 mm long, erect, drying yellow, puberulent with dendritic hairs, especially at base; stigma punctiform, 0.3 mm wide. Berries and seeds not seen. Chromosome number not known.

Distribution.— Cloud forest, 2200–3000 m in the province Chapare in Cochabamba, Bolivia (Fig. 3).

Phenology.— Flowering November–December.

Etymology.— The epithet refers to the red color of hypanthia.

Conservation Assessment.— Miconia cinnabarina is known from only from the type and one additional collection, made more than 50 years ago, in cloud forests of Bolivia. We use these criteria to categorize this species as endangered, very limited area of occupancy and limited number of locations: EN B2ab(i) ( IUCN 2001).

Additional specimens examined: BOLIVIA: Cochabamba: Prov. Chapare, km. 110 del camino al Chapare, 3000 m, 14 December 1966 (fl), Steinbach 613 ( NY, RSA!, US)

Miconia cinnabarina is similar to other Miconia species in Bolivia and Peru with tapering anthers and a small, terminal pore. Species of this alliance have been placed in Miconia sect. Amblyarrhena by Cogniaux (1891): Miconia bangii Cogn. in Rusby (1893:30), Miconia barbeyana Cogniaux (1891:872) , Miconia cookii Gleason (1933:43) , and Miconia terera Naudin (1850:196) . Miconia cinnabarina is basally-nerved to short-plinerved (up to 0.5 cm), with leaves 7.1–9.6 cm long and 2.1–3.1 cm wide, and often with pocket domatia, formed from the outgrowth of the leaf blade. In contrast, in M. cookii the leaves are up to 16 cm long and 5.5 cm wide ( Gleason, 1933), and the mite domatia are in the form of trichomes in the axils of the secondary veins on the abaxial surface of the leaves. Miconia barbeyana has much larger leaves, 12–21 cm. Miconia bangii is also endemic to Bolivia, but with much broader leaves (8–10 cm) and the stigma subpeltate instead of punctiform. Another similar species, Miconia terera , differs from this species in having a stem that is bluntly quadrangular instead of terete.

Specimens Beck 8742 ( US) and Smith 13905 ( US), both from La Paz, may be referred to this species, but exhibit much smaller leaves that are distinctly plinerved, without pocket domatia. In addition, Beck 4889 ( US) from La Paz may also be the same species, but this specimen is hirtellous throughout. Additional collections from Bolivia are needed to better assess morphological variability within this species.

Figures

FIGURE 4. Miconia cinnabarina A. Habit. B. Petiole, left to right in adaxial and abaxial view. C. Inflorescence cyme. D. Longitudinal section of flower at anthesis. E. Detail of calyx lobes and calyx teeth. F. Petal. G. Stamens, from left to right: side, ventral and dorsal view. Drawn from Steinbach 613, NY and Steinbach 548, NY.