Miconia povedae Kriebel & Oviedo, 2013

Oviedo-Brenes, Federico, 2013, A new species of Miconia from the remaining primary forest at Las Cruces Biological Station in Costa Rica, Phytotaxa 126 (1), pp. 55-60 : 57-59

Miconia povedae Kriebel & Oviedo sp. nov. ( Figs. 1 , 2 )

Type:— COSTA RICA. Puntarenas; Estación Biológica Las Cruces. En el Sendero Gamboa. Bosque primario con sotobosque bastante denso. Terreno plano muy húmedo cerca de un claro formado por la caída de varios arboles, 1157 m, 5 set 2008, 8.789333° N, - 82.970250° W, F . Oviedo-Brenes 231 (holotype: HLDG!; isotype: CR!) .

Shrub to small tree to 2.5–4 m tall. Young branches tomentose with golden to orange indument consisting of dendritic to stellate trichomes. Interpetiolar line inconspicuous and covered by indument as stems. Leaves sessile or subsessile, somewhat anisophyllous. Leaf blades 9–24 x 5–9 cm, 3–5-plinerved, with the innermost pair of veins diverging asymmetrically from the midvein 1.5–7 cm above the base, elliptic to obovate, the base attenuate, apex acuminate, the margin subentire to denticulate, adaxially glabrous, abaxially with moderate stellate and denritic pubescence on tertiary and higher order veins. Inflorescence a terminal and deflexed panicle with dichasial branches, 5–10 cm long, with about 3–7 sessile flowers clustered at the end of the branches; bracts 2, 3– 10 mm long, elliptic to ovate, persistent; bracteoles 2, ovate, ca. 1–2 x 0.5–1.25 mm, persistent. Flower buds 4–5 mm long, with petals forming an acuminate cone when mature. Hypanthium narrowly campanulate, sparsely stellate. Flowers 5(–6) merous, calyx not calyptrate but with the calyx lobes fused and irregularly rupturing in their early stages; calyx tube 0.3–0.5 mm, teeth 0.25–0.4 mm long, linearoblong. Petals 4.5–5.5 x 2–2.5 mm, white, spreading at anthesis, elliptic to elliptic-ovate, apically acute, glabrous. Stamens 10(–12), 4–5 mm long, radially arranged around the style; filament 2.25–2.75 mm long with a geniculation near the apex, white; anthers 1.5–2 x 0.6–0.8 mm, elliptic, somewhat laterally compressed, lacking an appendage or collar at the anther filament junction, yellow, pore ca. 0.15 mm wide, terminating the truncate apex. Ovary 5-locular, half superior, the apex beset with small brown glandular trichomes and elevated into a collar ca. 0.25 mm high around the style. Style ca. 6.4 mm long, straight to slightly curving, the stigma truncate, ca. 0.38 wide, the distance between the anther apex and the stigma ca. 1.5 mm, stigma truncate to capitellate, ca. 0.3 mm wide. Berry and seeds not seen.

Distribution. Known only from remnant primary forest at Las Cruces Biological Station, Puntarenas, Costa Rica, at about 1150 m in elevation ( Fig. 3 ).

Phenology. Miconia povedae has been collected in flower in July and September. The fruits remain unknown.

Etymology. It is with great honor that we name this species after Costa Rican botanist Luis Poveda Alvarez for his numerous contributions to botany and being an inspiration to us.

Discussion. Miconia povedae is a distinctive species on the basis of it’s strongly plinerved, sessile leaves with predominantly asymmetric leaf veins, sessile clustered flowers, fused calyx in bud, and five locular ovary ( Fig. 1 ). Among species of Miconia in Mesoamerica, very few have sessile leaves and a search for sessile leaves in Flora Mesoamericana ( Almeda, 2009) in the genus Miconia yielded other distantly related species namely Miconia impetiolaris ( Swartz 1788: 70) De Candolle (1828: 183) and M. tomentosa ( Richard 1792: 109) De Candolle (1828: 183) which differ, among other things, in having 3 or 4-locular ovaries (vs. 5- locular in M. povedae ).

Preliminary molecular phylogenetic analyses based on four chloroplast regions (acc D- psaI, atp F- atp H, psb K- psb L, and trn S- trn G) and two nuclear ribosomal regions (ETS and ITS) (Kriebel & Michelangeli, in prep.) place Miconia povedae in a clade that includes Clidemia fraterna Gleason (1937: 323) , Conostegia cinnamomea (Beurl.1856: 131) Wurdack (1978: 287) , M. dissitiflora Almeda (1989a: 146) , and M. grayumii Almeda (1989b: 209) . These species share mostly plinerved leaf venation with the innermost pair of veins diverging from the midvein in asymmetric fashion, flowers with exerted styles (approach herkogamous sensu Webb & Lloyd, 1996) and 5-locular ovaries. All these species differ from M. povedae in that their leaves are glabrous or have very inconspicuous indument and all have petiolate leaves except M. dissitiflora which can have subsessile leaves, but which differs from those of M. povedae by not tapering at the base. Another difference is that all these species have pedicellate flowers except for C. fraterna and M. povedae , both of which have sessile flowers. It is interesting that a species with such a narrow distribution as C. fraterna which is endemic to a small altitudinal belt from 975–1200 m in Costa Rica and Panama and known from few localities grows near by and is closely related to M. povedae which is only known from this forest. Besides differing from M. povedae in its glabrosity and petiolate, smaller leaves, Clidemia fraterna also differs in its unusual axillary inflorescence with pedunculate 3-flowered glomerules. In the case of M. grayumii , the latter is restricted mostly to the Caribbean lowlands of Costa Rica with a known locality in the Osa Peninsula on the Pacific slope. Miconia dissitiflora is endemic to lowlands of the Osa Peninsula and adjacent areas in Costa Rica and Conostegia cinnamomea has a broader distribution usually at lower elevation. This last species also differs from the rest in its calyptrate calyx.

Miconia calocoma Almeda (1989a: 144) and M. colliculosa Almeda (2000: 33) are also morphologically similar, and related to M. povedae , albeit more distantly (Kriebel & Michelangeli, in prep.). They share with M. povedae the evident rusty indument of dendritic to stellate trichomes, plinerved leaves with frequently asymmetric leaf veins, 5-locular ovaries in the case of M. colliculosa (4-locular in M. calocoma ), geniculate staminal filaments, and exerted styles (herkogamy). Miconia calocoma can be distinguished by its 4-merous flowers and petiolate leaves. Miconia colliculosa has sessile or subsessile flowers like M. povedae but can be distinguished by its petiolate leaves, larger bracteoles and anthers with dorsally inclined pores (vs. sessile leaves, smaller bracteoles and anthers with an apically truncate pore in M. povedae ). Both M. calocoma and M. colliculosa also are endemic to the Caribbean slope of Costa Rica and Panama.

Additional specimens examined. Costa Rica. Puntarenas: Estación Biológica Las Cruces. En el Sendero Gamboa, Bosque primario con sotobosque bastante denso, terreno plano muy húmedo cerca de un claro formado por la caída de varios arboles, 1157 m, 29 Jul 2010, 8.789333° N, - 82.970250° W, F . Oviedo-Brenes & Zahawi, R. A . 1215 ( HLDG); en el sendero Melissa, bosque maduro bastante denso, 1157 m, 12 Jun 2012, 8.790583° N, - 82.970250° W, F . Oviedo-Brenes 1908 ( HLDG) .

Figures

FIGURE 1. Miconia povedae Kriebel & Oviedo. A. Fertile branch and adaxial leaf surfaces. B. Abaxial leaf surfaces. C. Inflorescence showing clustered sessile flowers. D. Close up of the flower. E. Flower cluster terminating an inflorescence branch. F. Flower bud. G. View of the hypanthium from outside, note the acute calyx teeth on the rounded calyx lobes. H. Longitudinal cut of a flower with petals, stamens, and style removed. I. Ovary apex with minute glands. J. Petal. K. Lateral view of the stamen. L. Style. Photos: A–D by F. Oviedo (HLDG); E–L by R. Kriebel (NY). All photos of the type.

FIGURE 2. Miconia povedae Kriebel & Oviedo. A. Scanning electron micrograph of the abaxial leaf surface. B. Scanning electron micrograph of a close-up of a secondary vein on abaxial leaf surface. From F. Oviedo 1908 (HLDG).

FIGURE 3. Map of southern Central America with a close-up of Las Cruces Biological Station.