Psammisia pinnata Pedraza, 2015

Pedraza-Penalosa, Paola, 2015, New blueberry and mortino relatives (Ericaceae) from northwestern Colombia, PhytoKeys 49, pp. 33-58 : 35-36

Psammisia pinnata Pedraza sp. nov. Figures 1, 2, 3

Diagnosis.

Psammisia pinnata stands out among all other Psammisia s.l. because its distinctive large leaves (among the largest in the genus) that are subcoriaceous to chartaceous, elliptic to oblong, sometimes slightly asymmetrical, and which have pinnate venation; its petioles are pulvinate. Also distinctive is its ridged bark and conspicuous raceme rachises, and the relatively long flowers with staminal filaments fused at their very base.

Type.

COLOMBIA. Antioquia: Municipio Urrao. Corregimiento La Encarnación, Parque Nacional Natural Las Orquídeas, camino entre el páramo del Almorzadero y la cabaña de Calles, [6°31'N; 76°15'W. 1400 m], 31 Jul 2011 (fl, fr) P. Pedraza-Peñalosa, J. Betancur, M. F. González, R. Arévalo, D. Sanín, A. Zuluaga, A. Duque & J. Serna 2491 (holotype: COL!; isotypes: HUA!, E!, MO!, NY! [NY02058401]).

Description.

Terrestrial or epiphyte shrubs, more or less erect or with arching branches, 1.5 m tall; stems brown-black, ridged or subterete, with soft and small grooves twisting near nodes, glabrous, pith drying dark purple, most terminal branches usually hollow, and, at least in one occasion, inhabited by ants; twigs with a few deep ridges running lengthwise and often twisting near nodes, glabrous. Axillary buds compressed; prophylls 2, inconspicuous, valvate, ovate, 1.5-2 mm long, margin ciliolate, the hairs unicellular and eglandular (all indumentum composed of this type of hairs except when indicated), apex acute, glabrous. Leaves alternate; petiole subterete, thick and basally pulvinate, 1-2.8 cm long, glabrous; lamina subcoriaceous to chartaceous, elliptic to oblong, sometimes slightly asymmetrical (more evident in large leaves), (19-)23-45 × (5-)8.7-22 cm, base cuneate to sometimes nearly truncate, margin entire and eciliate except for the very young leaves with a handful of caducous apical hairs, apex (long or short) acuminate, glabrate with caducous hairs on both sides, adaxial hairs inconspicuous (<0.5 mm long), abaxial hairs often affixed atop of what seem to be minute laminar glands; laminar glands only evident abaxially, drying black, sparse, small, and round; venation pinnate, with up to 5 visible orders in dry specimens, 8-11 secondaries per side, these alternate (rarely subopposite), evenly dispersed along the lamina, ascending, brochidodromous, intersecondaries present toward midsection, midrib and secondaries adaxially impressed and abaxially raised, tertiaries well marked (in mature leaves), parallel among themselves and inserted at ca. 80-90° with respect to midrib. Inflorescence an axillary, solitary, 5-11-flowered raceme, often cauliflorous; inflorescence bracts caducous, chartaceous, ovate, 1.2-1.8 × 1.7-3 mm, margin entire and eciliate, apex obtuse, glabrous on both sides, venation obscure; rachis pink or magenta (fuchsia), 9-16 mm long, glabrous; floral bract 1, persistent, chartaceous, white, ovate, 1-3 × 1.5-2.5 mm, margin entire and eciliate, apex obtuse to acute, glabrous on both sides, venation obscure; pedicel pink or magenta (fuchsia), articulated with calyx, 9-23 mm long, glabrous; bracteoles 2, persistent, medially to distally inserted, opposite, chartaceous, white, ovate, 1.3-1.6 × 1-1.2 mm, margin entire and eciliate and with one or two pairs of stout masses of fimbria, apparently glandular in nature, easily breakable, apex acute, glabrous on both sides, venation obscure. Flowers 5-merous, actinomorphic, diplostemonous. Calyx pink or magenta, the lobes whitish with black marginal glands, cupuliform and sometimes slightly flaring out apically (urceolate in vivo), 6-8.5 mm long, glabrous; tube cupuliform, terete, ca. 3.5 mm long; limb spreading when dry (erect in vivo), 3-4 mm long; lobes ovate, 1-1.8 × 2-3.5 mm long, glandular margin on each side of the lobe (excluding the apex) sometimes breaking into stout segments of fusing glandular fimbria (sensu Luteyn 1983), margin eciliate, apex acute; sinuses obtuse (U-shaped); aestivation unknown. Corolla white (in bud basally pink and distally white), fleshy, not bistratose, conic, terete, 17-22 mm long, ca. 4.5 mm diam., ca. 2.5 mm wide at throat, glabrous within and without; lobes ovate, 1.2-1.3 × 1.4-1.5 mm, apex acute; aestivation valvate. Stamens 10, equal (though one cycle very slightly shorter than the other by <0.5 mm), 7-9 mm long, included, not adherent to corolla; filaments connate in basal 0.3-1.5 mm, 3-4.7 mm long, glabrous, marginally glabrous or glabrate, the hairs inconspicuous, ca. 0.1 mm long; anthers 7-8 mm long, connective spurless; thecae 4.5-5 mm long, prognathous, without basal appendage, papillate; tubules 2, free, straight, basally similar in width to thecae, 2.2-3 mm long, smooth, dehiscing by introrse slits almost as long as the tubules, 2.2-2.7 mm long. Ovary 5-locular; nectary not pulvinate, top of ovary flat or concave; style 17-20 mm long, included; stigma punctiform. Berry ca. 12 mm diam., turning green with age, the lobes yellowish and converging.

Distribution and ecology.

Psammisia pinnata is restricted to the rich humid premontane and montane forests of the Colombian Western Cordillera (Antioquia, Risaralda, and Valle del Cauca) where it is known to flower and fruit in January, April, and July. It grows at 950-1900 m.

Etymology.

The species name indicates the characteristic pinnate leaf venation.

Preliminary conservation status.

Psammisia pinnata occupies a large geographic area and ample altitudinal range, therefore there is no concern for its conservation status. However, it must be noted that Colombian Andes have alarming rates of deforestation and transformation, putting its natural vegetation under constant threat.

Discussion.

Psammisia pinnata is perhaps morphologically close to Psammisia multijuga Sleumer although it is clearly differentiable because of the soft bark grooves that twist near the nodes (vs. bark smooth in Psammisia multijuga ); dark purple branch pith (vs. white pith); elliptic to oblong (vs. ovate), apically acuminate (vs. abruptly acuminate [subcuspidato-acuminata]), and glabrous (vs. with inconspicuous hairs on both sides) leaves; black laminar glands evident (but small) abaxially (vs. few and inconspicuous); well-marked (abaxially) parallel tertiary venation, distinctively inserted at ca. 80-90° with respect to midrib (vs. not well-marked and reticulated); larger and fuller racemes with 5-11 flowers and rachises 9-16 mm long (vs. 2-flowered racemes and 2-4 mm long rachises [4-5-flowered fascicle in the protologue of Psammisia multijuga ]); glabrous calyces (vs. inconspicuously puberulous, the hairs eglandular and <0.5 mm long [glabrous in the protologue of Psammisia multijuga ]), with lobes with glandular margins (vs. eglandular); longer corollas (17-22 vs. 15 mm); basally connate staminal filaments, 3-4.7 mm long (vs. free, 2-2.5 mm long); tubules 2.2-3 mm long, dehiscing by slits almost as long as the tubules (vs. tubules 4.3-4.6 mm long, dehiscing by short slits 1.5 mm long).

Specimens examined.

COLOMBIA. Antioquia: Municipio Urrao, Corregimiento La Encarnación, Vereda Calles, Parque Nacional Natural Las Orquídeas, finca de Alfonso Pino, entre la divisoria de las quebradas La Virola y El Bosque, al NW de la cabaña Calles, 6°31'35"N; 76°15'50"W, 1450-1470 m, 27 Jan 2011 (fl, fr), P. Pedraza-Peñalosa et al. 2015 [COL! (2 sheets), HUA, MO, NY! (2 sheets)]; Parque Nacional Natural Las Orquídeas, sector Calles arriba, sitio El Macho, 6°32'22"N; 76°14'05"W, 1700-1750 m, 9 Dec 2013 (fl), N. R. Salinas et al. 865 [COL, E!, HUA, LPB!, MO!, NY! (2 sheets)]; Near top of Cordillera Occidental on trail from Encarnación to Parque Nacional Natural Las Orquídeas, 1900-2100 m, 27 Jan 1979 (fl), A. Gentry & A. Renteria 24641 (COL, MO!, NY!); Corregimiento Nutibara, region of Murrí, Nutibara-La Blanquita road, 1700-1800 m, 19 Apr 1988 (fl. buds), J. L. Luteyn et al. 12002 (AAU, COL, HUA, MO, NY!), 950-1380 m, 20 Apr 1988 (fl. buds), J. L. Luteyn et al. 12110 (COL, NY!). Risaralda: Municipio Mistrató, Inspección de Policia de Jeguadas, camino entre Jeguadas y Puerto de Oro, entre los sitios Curramaí y Pisones, 1200-1500 m, 3 Abr 1992 (fr), J. Betancur et al. 3312 (COL, NY!). Valle del Cauca: Municipio Cali, Finca Zingara, km 18 de la carretera Cali-Buenaventura, km. 4 vía Dapa, Corregimiento La Elvira, 1900 m, 2 Abr 2000 (fl), J. Giraldo-Gensini 903 (NY!).