Graffenrieda maklenkensis Humberto Mend., Alvear & Almeda, 2014

Almeda, Frank, Alvear, Marcela & Mendoza, Humberto, 2014, Two new species of Graffenrieda (Melastomataceae: Merianieae) from Colombia and Panama, Phytotaxa 163 (1), pp. 39-47 : 42-45

Graffenrieda maklenkensis Humberto Mend., Alvear & Almeda sp. nov. ( Figs. 2 , 3 )

Graffenrieda maklenkensis is characterized by its modally elliptic leaves with acute to obtuse base, long inflorescence (15−27 cm, including peduncle) with divaricate branching, short pedicellate flowers at anthesis, lepidote hypanthial indumentum mixed with translucent glandlike or resinous scurfy trichomes, and a calyx that is fused in bud but ruptures into four (rarely three) persistent lobes with apiculate apices that are evident at anthesis but caducous on fruiting hypanthia. Its closest relative is G. harlingii ( Wurdack 1976: 7) which differs in having smaller leaves with a rounded base and non-divaricate inflorescence branching, sessile flowers at anthesis, hypanthia (at anthesis) with a uniformly amorphous furfuraceous chocolate brown indumentum, and apically rounded, non-apiculate calyx lobes.

Type:― COLOMBIA. Santander: Municipio of Floridablanca, vereda La Judía, Cerro La Judía, Reserva Natural Campesina Los Maklenkes, Sendero Mario Mejía , 1900 m, 7°4.80' N, 73°2.70' W, 9 March 2012 (fl), F. Almeda, M. Alvear, H. Mendoza, G. Saavedra & D. Alvear 10643 (holotype: COL !; isotypes: CAS! , FMB !, HECASA! , NY! , UIS! )

Tree 3−12 m tall. Young branches, petioles and inflorescence branches sparsely rufescent lepidote becoming glabrescent. Internodes 1−3 cm long, the uppermost rounded-quadrangular becoming terete with age. Petioles canaliculate, 2.1−4 cm long. Leaves opposite and isophyllous, 11−16 × 6−8 cm, modally elliptic to oblong-elliptic; apex obtuse, sometimes short-cuspidate, base acute to obtuse and slightly revolute and decurrent, margin entire; adaxial surface glabrescent to glabrous at maturity, abaxial surface densely covered with a mixture of minute rufescent scales and whitish scales 0.1 mm in diameter; venation acrodromous, the primary nerve flat on the adaxial surface, prominent on the abaxial surface, with two pairs of secondary nerves, but only the innermost pair extending to the blade apex and converging with the primary nerve, the secondaries basal to very shortly suprabasal, diverging from the primary nerve up to 2 mm form the base, impressed on the adaxial surface and prominent on the abaxial surface, tertiaries (transversals) impressed on the adaxial surface, flat to slightly prominent on the abaxial surface. Inflorescence a terminal, open and multiflorous panicle, 15−27 cm long (excluding the peduncle, which is 5.5–8 cm long), with up to 4 nodes and 2 branches at the proximal and upper nodes; paracladia 7−14 cm long, with 3−4 levels of branching, the ultimate units of each paraclade with clusters of 3−9 flowers. Bracts and bracetoles not seen, apparently early caducous. Flowers 4−(5)-merous, morphologically protogynous, on pedicels 0.5−0.7 mm long. Hypanthium 3.6−4 × 2−2.5 mm, subcylindric to narrowly campanulate, externally slightly costellate, sparsely and caducously covered with rufescent scales and translucent glandlike scurfy trichomes (0.3 mm diameter); calyx tube less than 0.2 mm long, the exterior calyx teeth obsolete, calyx fused in bud then rupturing into four (sometimes three) mostly regular or irregular (if three in number) triangular-rounded lobes, 1− 1.3 mm long (from torus to apex), short-apiculate at the apex, with an indumentum like that of the hypanthium. Petals 4−5 × 2.5−3.5 mm, obovate, apically rounded to emarginate, white, entire and glabrous. Stamens 8−(10), isomorphic; filaments 2.5–3.8 mm long, pale yellow, ligulate; anther thecae 3.8−4.2 mm long, yellow, oblongsubulate, dorsally arcuate, the solitary pore 0.17−0.23 mm wide and ventrally inclined; connective prolonged 0.1 mm below the thecae and modified into a deflexed tooth-like appendage 0.2 mm long. Ovary ca. 2.3−2.5 mm long, elliptic to globose, apex lobulate, minutely granulose and sparsely glandular-puberulent, (3)−4-locular, basally 1/3 to 1/2 inferior; style 7−11 mm long, linear, straight to sometimes slightly curved apically, glabrous, stigma punctiform. Post-mature capsules 3 × 3 mm, globose; the enveloping hypanthium 4.5–5 mm long to the torus, bluntly costellate and glabrous externally. Seeds 0.7–1.1 × 0.4–0.5 mm, pyramidate, brown, lateral symmetrical plane oblong-arcuate to pyramidate, the chalazal end flattened horizontally, antiraphal symmetrical plane angulate to somewhat rounded, the raphal zone oblong and extending the entire length of the seed, testa smooth and shiny.

Distribution and habitat:― Endemic to the Cordillera Oriental in the Northern Andes of Colombia, in the departments of Santander and Norte de Santander. This species grows in Andean and High Andean forests at 1900− 3000 m. It has only been collected in areas with well preserved forest.

Phenology:― The type from Santander, which was collected in early January, has flowers. Other material collected in October was in flower and fruit.

Conservation status:― This species is known from two localities. One of the localities is currently protected in the Reserva Natural Campesina Los Maklenkes (0.12 km 2), that is adjacent to the Parque Regional Natural Cerro La Judía (35.21 km 2). These two areas are included within the Important Bird Area of Cerro La Judia (IBA CO171). The Area of Occupancy (AOO) based on this IBA area is 86 km 2 ( Franco et al. 2009, CDMB 2012, Birdlife International 2013). The population in Norte de Santander is not in a protected area and we have no information on its size. However, ongoing deforestation is a major environmental threat in the region. Based on our current knowledge and the IUCN guidelines and criteria ( IUCN 2001, 2011), this species is assigned a provisional IUCN conservation status of Endangered (EN).

Etymology:― The specific epithet is taken from the name of the protected area where we collected the type specimens, “Reserva Natural Campesina Los Maklenkes”.

Additional specimens examined (paratypes):― COLOMBIA. Santander: Municipio de Floridablanca, La Judía, Cerro La Judía , 2049 m, 7°05'28"N, 73°02'40"W, 11 October 2005 (fr), L. L. Roa-Fuentes 403 ( COL!) ; Norte de Santander: Municipio Villa Caro, Vereda al páramo de Guerrero , en laderas de fuertes pendientes en franja de bosque, 3000 m, 10 October 2009 (fl), R. Sánchez 12706 ( HECASA!) .

Discussion: — Graffenrieda maklenkensis can be recognized by its appressed lepidote rufescent indument on branches and inflorescence, the conspicuous tertiary and quaternary venation, 2 pairs of secondary nerves, the open divaricately branched inflorescence with 4−5-merous, short pedicellate (at anthesis) flowers, hypanthia with a mixture of rufescent scales and whitish glandlike scales, calyx lobes with a caducous apiculate apex, and obovate apically rounded-emarginate petals. Among described species, Graffenrieda maklenkensis is most similar to G. harlingii , a species centered in southern Ecuador with one known population in Colombia (Antioquia), but the latter has smaller leaves (5−10 × 3.5−6 cm) with a rounded base, quaternary venation that is not conspicuous on abaxial foliar surfaces, smaller inflorescences with poorly developed and unbranched paracladia, sessile flowers at anthesis, hypanthial indumentum that is dark chocolate brown and amorphous furfuraceous at anthesis, calyx lobes that lack a caducous apiculate apex, petals that are obovate with a rounded-obtuse apex, anther connective prolonged 0.4 mm below the thecae, and dorso-basal anther appendages 0.4−0.7 mm long.

Another vegetatively similar species with 4-merous flowers is G. reticulata Wurdack (in Maguire & Wurdack 1958: 110), endemic to Cerro de La Neblina in Venezuela, which has a consistently 3-locular ovary, smaller leaves (6–12 × 3–6 cm) with only one pair of secondary veins, shorter petioles (1−2 cm), and abaxial leaf surfaces that are glabrous ( Gröger 2001). Graffenrieda tristis Triana (1871: 72) L.O. Williams (1963: 564) , another species with 4- merous flowers from Peru, is also similar vegetatively but differs by its smaller leaves with only one pair of secondary veins, pedicellate flowers (pedicels 2−3 mm long), and calyptrate calyx.

Figures

FIGURE 2. Graffenrieda maklenkensis. A. Flowering branch. B. Leaf base detail (abaxial surface). C. Indumentum detail on abaxial leaf surface. D. Flower. E. Stamen, lateral view (left) and dorsal view (right). F. Petal (adaxial surface). G. Flower bud showing morphologic protogyny. H. Hypanthium (at anthesis) in longitudinal section. I. Ovary cross section. J. Fruiting hypanthium. (A–J from Almeda et al. 10643, CAS).

FIGURE 3. Graffenrieda maklenkensis. A. Branch showing leaves (adaxial surfaces) and inflorescence.B. Leaf showing primary and secondary nerves and revolute base (abaxial surface). C. Flower and young fruiting hypanthia. D. Hypanthia in post-mature fruit. (all photos from the type collection by F. Almeda).