Miconia kellyana Almeda & R.B. Pacifico, 2023

Almeda, Frank & Pacifico, Ricardo, 2023, A new Miconia (Melastomataceae) from Cusuco National Park, Honduras, Phytotaxa 578 (2), pp. 199-206 : 200-205

Miconia kellyana Almeda & R.B. Pacifico , sp. nov. ( Figs. 1–2 )

Type:— HONDURAS. Cortés: Parque Nacional El Cusuco (CNP), Sierra del Merendón, W of San Pedro Sula, 750 m along trail GUI, N from Guanales camp [ca. 15.491678°N, 88.236423°W], 1425 m, 16 June 2011, fl., D.L. Kelly & A.C. Dietzsch 14054 (holotype TEFH-image!; isotypes: CAS!, K-image!, TCD-image!).

Diagnosis:— Miconia kellyana can be distinguished from M. chinantlana by its upper internodes that are covered with a mixture of simple trichomes, apically bifid trichomes, and stalked-stellate trichomes (vs. a mixture of only short-stalked and long-stalked stellate trichomes), petioles 2.5–7 mm long (vs. 13–48 mm long), elliptic-lanceolate 5-plinerved leaf blades that are 1.4–3.5 cm wide, basally obtuse to cuneate and never oblique (vs. ovate to lance-ovate 5–7-plinerved blades that are 4–9.5 cm wide, basally broadly rounded to subcordate and oblique on some leaves), and hypanthia copiously covered with simple spreading trichomes intermixed with some apically bifid trichomes and a few stalked-stellate trichomes (all 1–1.5 mm long) that completely conceal the surface at anthesis (vs. covered with spreading stalked stellate trichomes mostly 0.25 mm long and not concealing the surface at anthesis).

Shrubs 2–3 m tall, cauline internodes of uppermost branchlets rounded, copiously covered with a mixture of brown simple trichomes, stalked-stellate trichomes and apically bifid trichomes 0.5–1 mm long becoming glabrate with age. Leaves of a pair equal to unequal in size, concolored when dry, petioles 2.5–7 mm long, canaliculated adaxially and densely covered with an indumentum like that of upper internodes; blades 5–13.5 × 1.4–3.5 cm, membranaceous when dry, lanceolate to elliptic-lanceolate, apex attenuate, base obtuse to cuneate, margin essentially entire, 5-plinerved with an elevated primary midvein and one pair of secondaries mostly alternately diverging from the midvein 0.9–2.5 cm above the blade base, the tertiary veins also conspicuous, elevated and spaced 3–4 mm apart at the wider portions of the blade, adaxially copiously beset with ± appressed smooth trichomes 0.25–1 mm long, abaxially prevailingly covered with spreading stalked-stellate trichomes 0.5 1 mm long intermixed with some apically bifid and simple trichomes of the same length on primary, secondary and higher-order veins, and on the blade surface. Inflorescence terminal, thrysoid, 3–5 cm long including a peduncle 0.5–1 cm long, copiously covered with spreading yellowish smooth apically bifid trichomes mostly 0.5–1 mm long; bracts of the rachis nodes 1.5–3 mm long, sessile, persistent, subulate, glabrous adaxially, abaxially sparsely covered with smooth and/or apically bifid trichomes 0.25–0.5 mm long; bracteoles 1.5–2 mm long, sessile, persistent, linear-subulate, indumentum on the abaxial surface like that of the bracts. Flowers 5(6)-merous, perfect, subsessile or on pedicels 0.5 mm long, hypanthia campanulate, 3–4 × 3 mm, copiously covered with yellowish smooth simple and some inconspicuously apically bifid trichomes 1–1.5 mm long that completely conceal the surface at anthesis; calyx tube 0.5 mm long, the calyx lobes 1 × 1.5 mm, bluntly triangular (at anthesis), glabrous adaxially and covered with indumentum like that of the hypanthia and calyx teeth abaxially, the exterior calyx teeth 5(6), subulate, 4–6 mm long and ca. 0.12 mm or less wide at the base, exceeding the calyx lobes in length and concealing them; torus glabrous adaxially. Petals 3–4 × 2.5 mm, white becoming pinkish with age, glabrous, obovate, apically rounded, apex rounded and beset with gland-tipped trichomes. Stamens 10(12), isometric and isomorphic, forming a ring around the style at anthesis but becoming deflexed to one side of the flower opposing the style, filaments 2–2.5 mm long, glabrous, complanate, subulate, white becoming pinkish-red with age; anthers 3–4 × 0.5 mm, yellow but turning reddish-pink with age, oblong, broadly rounded to ± truncate at the apex with a ventrally inclined apical pore; connective slightly thickened dorsally and prolonged ventro-basally above the filament insertion into a bilobulate ventral appendage less than 0.25 mm long. Ovary (at anthesis) ca. 2/3 inferior, 5-locular, ± globose, apex rounded and beset with gland-tipped trichomes. Styles straight and curved distally but typically becoming declinate, 6–8 mm long, white, sparsely to moderately beset with gland-tipped trichomes up to 0.25 mm long for the basal ⅓ to ½ of their length; stigmas punctiform. Mature berries and seeds not seen.

Paratypes:― HONDURAS. Cortés: Parque Nacional El Cusuco ( CNP), Sierra del Merendón , W of San Pedro Sula. Plot GU/2 / SS5 , 2000 m by trail GU2 , SE from Guanales campsite, [ca. 15.48020°N, 88.22665°W], 1505 m, 15 June 2013, D. L. Kelly & A. C. Dietzsch 15016 ( CAS!, EAP!); CNP, 1100 m by trail GU1 from Guanales campsite, 15.49420°N, 88.23832°W, 1600 m, 2 August 2018, A. Ward CUGU2018 01 (NY); CNP, Guanales trail GU1 , 15.49486°N, 88.23832°W, ca. 1650 m, 2 August 2018, A. Ward CUGU2018 02 (BM, CAS!); CNP, 2000 m by trail SE from Guanales campsite, [ca. 15.48020°N, 88.22665°W], 1505 m, 2 August 2018, A. Woolf CUGU2018 03 (CAS!, MO); CNP, near Guanales campsite, 15.48124°N, 88.22294°W, 1532 m, 23 June 2019, A. Ward CUGU2019 01 (CAS!, EAP); CNP, by trail GU2 , SE from Guanales campsite, [ca. 15.494403°N, 88.237927°W], 1575 m, 23 June 2019, A. Ward CUGU2019 03 (P); CNP, by trail GU2 , SE of Guanales campsite, [ca. 15.493993°N, 88.237964°W], ca. 1550 m, 23 June 2019, A. Ward CUGU 2019 02/04 ( HEH).

Distribution, Habitat, and Phenology:— Miconia kellyana is known only from Cusuco National Park in the Sierra del Merendón of northwestern Honduras at an elevation of 1425–1650 m ( Fig. 3 ). It can be occasional or locally common along trails and in the understory of mixed secondary broadleaf montane forest or along trails in pinedominated forest. It was collected in flower in June and August; fruiting time is unknown.

Conservation Status:—The montane cloud forest habitat where Miconia kellyana grows is within the borders of Cusuco National Park (CNP) which was established after the passing of the Cloud Forest Act in 1987. The park covers an area of approximately 23440 hectares with a recommended core zone of 7690 hectares and a buffer zone of 15750 hectares. It protects an elevational range from 500 to 2425 m. The park is largely covered with closed canopy broadleaved forest, moist pine forest, and dwarf forest restricted to mountain peaks and ridge tops ( Martin et al. 2021). It is part of the Mesoamerican biodiversity hotspot according to Conservation International ( Mittermeir et al. 2005). For a detailed review of the ecological importance of CNP and its exceptional biodiversity see Martin et al. (2021).

Both EOO (0.46 km 2) and AOO (8 km 2) estimated by GeoCAT support a Critically Endangered (CR) conservation status for Miconia kellyana . It appears to be a species of high conservation concern like the other recently described flowering plants from CNP mentioned in the introduction. All of the known collections of this species were made around the Guanales campsite which is located near the southeastern border of the park ( Fig. 3 ) where the integrity of the CNP ecosystem is threatened by land cover changes that include deforestation (particularly conversion of forest to coffee plantations), poaching, unsustainable land management practices, human population growth, infrastructure intensification, and climate change ( Martin et al. 2021). According to D. L. Kelly (pers. comm.) the total population of this species numbers in the hundreds of individuals. He notes that it is locally plentiful but confined to one small vulnerable area and not far from a village (La Fortuna) close to the lower fringes of the Park’s more or less intact montane forest vegetation.

Etymology: — The specific epithet honors Dr. Daniel L. Kelly (b. 1948), collector of the type, in recognition of his important studies of forest biodiversity, structure, and dynamics, and epiphytic plant communities at Cusuco National Park and elsewhere in the American tropics (chiefly Jamaica, and Venezuela).

According to Cordula Lennkh, a local name for Miconia kellyana is “ Sirín tamoso ” (= downy melastome or fluffy melastome) probably alluding to the overall indumentum of vegetative and floral parts.

Affinities:— Miconia kellyana is part of a group of morphologically similar Mesoamerican species that includes M. chinantlana ( Naudin 1852: 318) Almeda (2005: 503) , M. globulifera Naudin (1850: 139) , and M. tixixensis Standley & Steyermark (1944: 181) . All of these species share a shrubby habit, thyrsoid inflorescences, sessile or subsessile prevailingly 5-merous flowers with well-developed calyx teeth, white petals, isometric and isomorphic stamens with yellow anther thecae, glandular-puberulent ovary apices ( Fig. 1K ), and 5-locular ovaries; the other species in the group share purple-black mature berries, and ovoid seeds with a vaguely rugulate testa.

The label on the type, Kelly & Dietzsch 14054, describes the flowers as having six sepals, six petals, and 12 stamens. A close examination of flowers on the fertile collections available for study showed a few 6-merous flowers but 5-flowers with 10 stamens appear to be the prevailing condition as it is in all of the close relatives enumerated above.

Miconia kellyana appears to be closest to M. chinantlana , a species of Mexico (Chiapas and Oaxaca) and Guatemala; the distinctions are highlighted in the diagnosis and key below. It is also morphologically similar to M. globulifera of Mexico (Chiapas, Oaxaca, and Veracruz) and Guatemala, and M. tixixensis of Guatemala ( Almeda 2009). Miconia globulifera has an indumentum on upper internodes and abaxial foliar surfaces like that of M. kellyana but its leaf blades are 5–7-nerved or 5–7-plinerved, wider (3.5–9.7 cm), and obtuse to broadly rounded and commonly oblique basally. Miconia globulifera also differs consistently from M. kellyana in having shorter calyx teeth (0.5–1 mm long) that barely exceed the calyx lobes in length, and in having glabrous styles. Although the elevational distributions of the two species overlap, the former has a range (1200–2500 m) that exceeds M. kellyana by nearly 900 meters.

The rare and little-collected Miconia tixixensis , which is known from the type and two other collections (Chiquimula and Baja Verapaz respectively), is also superficially similar to M. kellyana . Its petioles are longer (10–23 mm vs. 2.5–7 mm); its indumentum on upper internodes, petioles, inflorescences, hypanthia, and calyx teeth consists of short-stalked and long-stalked stellate trichomes (vs. a mixture of simple, stalked-stellate, and apically bifid trichomes), its adaxial surfaces of young leaves are covered with deciduous and spreading short-stalked stellate trichomes mostly 0.25 mm long that subsequently lose all or at least the distal portion of the trichome stalks resulting in a somewhat scabrous texture at maturity (vs. covered with ± appressed or somewhat ascending smooth trichomes 0.25–1 mm long that are persistent); and its shorter calyx teeth are 3 mm long (vs. 4–6 mm long).

The berries of all the close relatives of Miconia kellyana are purple-black when mature and the seeds are ovoid with a regulate testa; we suspect that our new species may also be similar or identical in these characters.

Miconia kellyana appears to differ from all of its close relatives in having staminal connectives that are prolonged ventro-basally above the filament insertion into small bilobulate ventral appendages less than 0.25 mm long ( Fig. 1I, J ). It can be distinguished from its closest relatives by the diagnostic characters noted in the following key:

1. Adaxial surfaces of young leaves covered with short-stalked stellate trichomes mostly ca. 0.25 mm long: these trichomes are deciduous on older leaves such that the stellate trichomes lose all or a distal portion of the stalks and stellate arms, creating a scabrous surface at maturity ............................................................................................................................................ M. tixixensis

1. Adaxial surfaces of young and older leaves densely beset with a persistent cover of ± appressed or somewhat spreading smooth trichomes 0.25 1.5 mm long.

2. Calyx teeth 0.5 1 mm long, barely exceeding the calyx lobes in length and not concealing them at anthesis; style glabrous........... ...................................................................................................................................................................................... M. globulifera

2. Calyx teeth 2 6 mm long, greatly exceeding the calyx lobes in length and usually totally or .. partly concealing them at anthesis; style glandular-puberulent.

3. Upper internodes covered with a mixture of short-stalked and long-stalked stellate trichomes; abaxial leaf surfaces moderately covered with spreading stalked-stellate trichomes 0.25 0.5 mm long; petioles mostly 13 48 mm long; hypanthia covered with short-stalked and long-stalked stellate trichomes mostly 0.25 mm long that do not conceal the actual surface at anthesis ............... .................................................................................................................................................................................... M. chinantlana

3. Upper internodes covered with a mixture of simple trichomes, apically bifid trichomes, and stalked-stellate trichomes; abaxial leaf surfaces covered with stalked-stellate trichomes 0.5 1 mm long, intermixed with apically bifid and simple trichomes of the same length; petioles mostly 2.5 7 mm long; hypanthia prevailingly covered with an indumentum of simple spreading trichomes sparingly intermixed with some apically bifid trichomes and a few stalked-stellate trichomes that completely conceals the surface at anthesis ......................................................................................................................................................................... M. kellyana

Figures

FIGURE 1. Miconia kellyana. A. Habit. B. Indumentum detail of upper internode. C. Representative leaf (abaxial surface). D. Representative leaf (adaxial surface). E. Indumentum detail of abaxial leaf surface. F. Indumentum detail of adaxial leaf surface. G. Flower at anthesis (profile view). H. Petal (adaxial surface). I. Stamen (ventral view). J. Stamen (lateral view). K. Style and ovary apex. Drawn from CAS isotype.

FIGURE 2. Miconia kellyana field photos. A.An individual of M. kellyana (white arrow) in a forest understory at Cusuco National Park, Honduras. B. Flowering branches. C. Close-up of two flowers in post-anthesis. All photos by Michael Darling.

FIGURE 3. Distribution of Miconia kellyana.A. CentralAmerica and surroundings with Honduras highlighted in blue. B. Honduras with the Cusuco National Park region highlighted in red. C. Cusuco National Park (outlined in red), with campsites and trails monitored by the Wallacea project, and distribution records of M. kellyana.