Meriania sumatika Rob. Fern., R. Goldenb. & Michelang., 2022

Rocío, Robin Fernandez-Hilario, Gonzáles, Pilar Rojas, Villanueva-Espinoza, Rosa, Lajo, Leticia, Wong Sato, Akira A., Paredes-Burneo, Diego, Pillaca-Huacre, Luis, Michelangeli, Fabián A. & Goldenberg, Renato, 2022, Nine new species and a new country record for Meriania (Melastomataceae) from Peru, Willdenowia 52 (1), pp. 39-74 : 63-66

8. Meriania sumatika Rob. Fern., R. Goldenb. & Michelang. , sp. nov. – Fig. 15–16 .

Holotype: Peru, Cusco, Prov. Urubamba, Dist. Machupichu, Santuario Histórico de Machupicchu y en Camino Inca , 13°09'10"S, 72°31'00"W, 2060 m, 14–22 Oct 1987 (fl., fr.), P. Nuñez & J. Arque 8369 ( CUZ accession no. 15097 !; isotypes: F accession no. 2028864 !, US barcode 02925646 !) .

Diagnosis — A species differing from other congeners by the combination of 10-costate hypanthia (ridges up to 4.5 mm high in fruit), spreading, reddish purple corollas, large petals (46–55 mm long), dimorphic stamens, stamen connectives with two appendages, one a descending dorsobasal appendage and the other a blunt ascending dorsal appendage, and antisepalous stamen connectives with laterally expanded dorsobasal appendages.

Morphological description — Tree up to 20 m tall; young branches and petioles tomentose with elongated trichomes with greatly roughened base, these up to 1 mm long, sparsely to densely on young branches, densely on petioles. Young branches quadrangular, 2.5–4.5 mm in diam., nodes without interpetiolar flaps. Leaves opposite, isophyllous, rarely anisophyllous. Petioles quadrangular, 1.1–4.8 cm long, without projections. Leaf blades coriaceous, 10–17 × 3.7–8.8 cm, elliptic to ovate, apex acute, base acute to obtuse, margin finely serrulate on distal half to two-thirds, discolorous; venation acrodromous and suprabasal, with one two of secondaries (lateral nerves), first pair diverging 2–3 mm from base of blade, second pair diverging 5–10 mm from base of blade and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 30–40 on each side of primary, percurrent, 2–10 mm distant from each other, midvein, secondary and tertiary veins impressed, reticulation barely visible on adaxial surface, midvein and secondary veins salient, tertiary veins prominent and reticulation visible or barely visible on abaxial surface; adaxial surface flat, olive-green when dry, glabrous or with sparse elongated trichomes with greatly roughened base, denser near base of midvein, up to 1 mm long; abaxial surface greenish ferruginous to ferruginous when dry, densely tomentose to villose with elongated trichomes with greatly roughened base up to 1.5 mm long, similar to ones on petioles, covering almost entire surface. Inflorescences terminal panicles, erect, 10–22.5 × 12–23 cm, few-flowered; axis and peduncle densely tomentose with trichomes similar to ones on twigs and petioles, up to 1.5 mm long. Peduncle 2–5.5 cm long, quadrangular. Main axis 3.1–10.4 cm long, quadrangular, with 1–2 pairs of proximal paraclades and two nodes, subdistal node with 2 flowers, distal node with a dichasium. Paraclades in ones proximal pairs, 5.5–11.7 cm long; flowers in regular dichasia at ends of branchlets. Bracts foliaceous, persistent, 9.9–11.5 × 2.8–6.6 cm, petioles 1.1–3.7 cm long, shape and indumentum similar to principal leaves; sometimes with one pair of additional bracts on proximal nodes of main axis , c. 6 × 1.6 cm, petioles 1 cm long. Bracteoles (in Huamantupa & al. 2060) caducous, 17–20 mm long, lanceolate, indumentum similar to ones on bracts. Flowers 5–merous, with spreading corollas. Pedicels c. 6 mm long, ferruginous, densely tomentose, trichomes up to 1 mm long, similar to ones on inflorescence axis. Hypanthium c. 9.5 × 10.5–11 mm, campanulate, 10-costate, ridges irregular and obscured by trichomes, up to 2–5 mm high, ferruginous, outer surface densely tomentose to villose with trichomes similar to ones on pedicels, up to 1.5 mm long, inner surface glabrous; torus glabrous. Calyx opening regularly, ferruginous, outer surface densely tomentose to villose with trichomes similar to ones on hypanthia, up to 1.5 mm long, inner surface moderately tomentose with same trichomes, up to 1 mm long; tube 2.5–3.5 mm long; lobes 14.5–15 × 8–9 mm, acute, each with a falcate dorsal projection, 14.5–15.5 mm long. Petals 46–55 × 38 mm, 4–5 mm wide at base, obovate and slightly asymmetric, apex rounded, margin entire, purple, glabrous. Stamens 10, dimorphic, all bent to one side of flower at anthesis giving flower a zygomorphic appearance; antisepalous stamens filaments 28–29 mm long, purple, flat, glabrous, connectives not prolonged below thecae, dark purple in thecae, white in transition to descending dorsobasal appendage, with very short and irregular projections on dorsal surface from tip of descending dorsobasal appendage to base of ascending dorsal appendage, with two appendages, one descending dorsobasal, laterally expanded, 7–8 mm long, acute and crowned, yellow, other ascending dorsal appendage c. 1 mm long, blunt, purple, 4.5–5 mm from tip of descending dorsobasal appendage, anthers 14–15 mm long, lanceolate, dark purple, glabrous, with its apical third slightly reflexed, opening by one dorsally inclined pore, thecae surface corrugated; antipetalous stamens filaments 24–25 mm long, purple, flat, glabrous, connectives not prolonged below thecae, dark purple in thecae, white in transition to descending dorsobasal appendage, with very short and irregular projections from tip of descending dorsobasal appendage to base of ascending dorsal appendage, denser on dorsal surface, with two appendages, one descending dorsobasal, 12–13 mm long, acute, yellow, other ascending dorsal appendage, c. 1 mm long, blunt, purple, 7–7.5 mm from tip of descending dorsobasal appendage, anthers 15.5–16 mm long, lanceolate, dark purple, glabrous, straight, opening by one dorsally inclined pore, thecae surface corrugated. Ovary 5–locular, superior, free, c. 6.5 × 4 mm, oblong, colour unknown, not exceeding hypanthium length, glabrous; style c. 15 mm long, reddish purple, glabrous, incurved at apex and opposite to anthers at anthesis; stigma punctiform and minutely papillate, c. 0.75 mm wide, colour unknown. Fruits capsular (velatidia), with a persistent hypanthium, clearly 10-costate, ridges up to 4.5 mm high, calyx caducous; mature ovary c. 11 × 10–10.5 mm, spheroid, slightly costate, completely concealed by hypanthium; fruiting pedicels 8–11 mm long. Seeds triangular-linear, 1–1.5 mm long, numerous.

Phenology — Flowering occurs in February, May and October and fruiting in May and October.

Distribution and ecology — Meriania sumatika is endemic to high-elevation montane forests within the Machu Picchu National Sanctuary (Urubamba province) and in the Santa Ana district (La Convención province) in the Department of Cusco, between 1800 and 2900 m. Individuals of this new species have been previously recorded by Alfaro & al. (2018), as M. tomentosa , in “Wiñaywayna” and growing with Aniba coto (Rusby) Kosterm. ( Lauraceae ), Gordonia fruticosa (Schrad.) H. Keng ( Theaceae ), Hieronyma oblonga (Tul.) Müll. Arg. ( Phyllanthaceae ), Meliosma peytonii A. H. Gentry ( Sabiaceae ) and Myrcia fallax (Rich.) DC. ( Myrtaceae ).

Conservation status — All Meriania sumatika specimens were collected in the Machu Picchu National Sanctuary (except Huamantupa & al. 2060). Within this sanctuary, the main threat are forest fires for the establishment of crops ( CENEPRED 2020). Therefore, following IUCN (2012, 2019) guidelines and based on an estimated area of occupancy of 24 km 2, we recommend the category Endangered EN B 2ab(iii) for this species.

Etymology — The specific epithet comes from the Quechua “sumaq” (= beautiful) and “tika” (= flower), referring to large showy flowers of this species. Because “tika” is a noun in apposition, the epithet retains its own termination irrespective of the gender of the generic name (see Turland & al. 2018: Art. 23.5).

Discussion — Meriania sumatika is distinguished from other species within the genus by the combination of 10-costate hypanthium, spreading, reddish purple corolla and large petals (46–55 mm long). In the Andean region only two other species have costate hypanthia, M. campii Wurdack and M. costata Wurdack , both species endemic to Ecuador. Meriania sumatika is distinguished from M. campii by the leaf blades 10–17 × 3.7–8.8 cm (vs 6–12 × 4–8 cm in M. campii ), calyx lobes with falcate dorsal projections, 14.5–15.5 mm long (vs blunt carnose, 1.7– 4 mm) and dimorphic stamens (vs isomorphic). Meriania sumatika also shares falcate dorsal projections on the calyx lobes with M. costata . Nevertheless, M. sumatika differs from M. costata by its spreading, reddish purple corollas (vs campanulate, reddish orange), petals 46– 55 mm long (vs c. 22 mm) and stamen connectives not prolonged below the thecae (vs 1.5–1.7 mm prolonged).

Among Peruvian species of Meriania , M. sumatika probably belongs in a group of species that includes M. amischophylla , M. vargasii Wurdack and M. weberbaueri J. F. Macbr. ; the first and third species are endemic to central Peru and the second one is endemic to S Peru. These species are trees with tomentose to villose indumentum, calyx lobes with dorsal projections, spreading corollas, deep pink to reddish purple petals, dimorphic stamens and antisepalous stamen connectives with laterally expanded descending dorsobasal appendages. Within this group M. sumatika can be distinguished by its 10-costate hypanthium (vs terete in the other species), calyx lobes with falcate dorsal projections, 14.5–15.5 mm long (vs acute, 1–1.5 mm in M. amischophylla ; falcate, 5–6 mm in M. vargasii ; and acute, up to 3 mm in M. weberbaueri ) and petals 46–55 mm long (vs 19–32 mm in M. amischophylla ; 20–24 mm in M. vargasii ; and 20–25 mm in M. weberbaueri ).

Almost all Meriania sumatika specimens were previously determined as M. tomentosa . In fact, the two species are almost indistinguishable based on vegetative characters. Meriania sumatika differs from M. tomentosa by its 10-costate hypanthium (vs terete in M. tomentosa ), lobed calyx with regular dehiscence (vs calyptrate with irregular dehiscence) and spreading, reddish purple corollas (vs campanulate, reddish orange).

Here we place Huamantupa & al. 2060 (in flower bud) in Meriania sumatika with reservation, because it has slightly costate hypanthia and calyx lobes with smaller dorsal projections (4–5 mm vs 14.5–15.5 mm). In addition, this specimen was collected 41 km away from the others.

Additional specimens examined (paratypes) — PERU: Cusco, Prov. Urubamba, Dist. Machupichu, Intipata, Santuario Histórico de Machu Picchu , 2950 m, 10 Feb 1990 (fl.), A. Cano & al. 2874 ( HUT!) ; Wiñay-Wayna, Machupichu , 2850–2900 m, 21 May 1991 (fr.), H. Dueñas 27 ( CUZ!) ; Microcuenca Wiñaywayna, Wiñaywayna-Intipunku , 13°10'23.04"S, 72°32'03.44"W, 2700 m, 24 Jun 2001 (fr.), R. Tupayachi & al. 4926 ( CUZ!) ; camino Inca, entre Wiñay Wayna e Intipunku, quebrada Wacraytambo , 13°10'42"S, 72°32'02"W, 2737 m, 24 May 2004 (fl., fr.), W. Galiano & al. 6410 ( CUZ!, NY!) ; Prov. La Convención, Dist. Santa Ana, Potrero , 13°53'56"S, 72°43'50"W, 1800 m, 27 May 2002 (fl. bud), I. Huamantupa & al. 2060 ( USM!) .

Figures

Fig. 15. Meriania sumatika – A: terminal fertile branch with inflorescence; B: infructescence branch; C: flower at anthesis, apical view; D: petal; E: antisepalous stamen, lateral view; F: antipetalous stamen, lateral view; G: longitudinal section of flower with petals and stamens removed. – A from W. Galiano & al. 6410; B–G from P. Nuñez & J. Arque 8369. – Drawing by Leticia Lajo.

Fig. 16. Distribution map of Meriania sumatika.