Brunfelsia cabiesesiana J.G.Graham, 2016

Graham, James G. & Janovec, John P., 2016, A remarkable new species of Brunfelsia (Solanaceae) from the eastern Andes of Central Peru, PhytoKeys 75, pp. 81-91 : 83-85

Brunfelsia cabiesesiana J.G.Graham sp. nov. Figures 2 , 3 , 4 , 5 , 6

Type.

PERU. Ucayali: Prov. Coronel Portillo, Dist. Iparia, Reserva Comunal El Sira , 1500 m, 9°27.8'S, 74°33.5'W, 24 Oct 2007, J. G. Graham 5970 (holotype: MOL; isotypes: F, NY) .

Diagnosis.

Brunfelsia cabiesesiana distinguitur ab omnibus aliis speciebus Brunfelsia possidendo cauliflorus inflorescentiis.

Description.

Pachycaulescent shrub to few-branched, sprawling small tree to 3 m. Trunk solitary, terete, to 5 cm in diameter near base. Bark brownish-gray and rough at stem base, becoming dark green and smooth on upper stem; glabrous. Branches lacking, or, if present, terete, to 2 cm diameter, tending to arch over with age, with vertically ascending branchlets. Leaves crowded toward apex of stem, subverticillate, up to seven per whorl, simple, often in terminal whorls on single stem, occasionally in multiple whorls 20-30 cm apart; petioles sub-terete, often canaliculate above, up to 1cm long, 3-5 mm wide, brownish when dry, blades elliptic to broadly obovate, 15-35 cm long, 6-15 cm wide, glabrous, dull, dark green above, pale green beneath, young leaves purplish, smooth, subcoriaceous, glabrous, the base narrowly decurrent, the apex cuspidate to lightly acuminate, the margins entire; the midvein prominent below, the secondary veins 6-8-nerved, spaced up to 2 cm apart, arcuate-ascending, with light collective vein on margin, the tertiary venation reticulate. Inflorescences cauline, corymbiform, flowering branches stunted, woody at base, persistent, leafless, densely bracteate, to 3 cm long, with 1-7 branchlets up to 5 mm long, few flowered, usually only 1 flower per branchlet. Bracts spirally arranged, lanceolate, lightly keeled below, 0.7-1.3 mm long, tan to brown, lightly pubescent at base and along margins. Flowers showy violet fading with age, with 5-angled white spot at mouth. Pedicels 4-10 mm long, slender, 1.5-2 mm in diameter, glabrous. Calyx tubular-campanulate, weakly inflated, 2-2.3 cm long, 6-8 mm in diameter, ellipsoid to ovoid in bud, yellow-green to green, lightly punctate, firmly membranaceous, connate at base, 5-lobed at apex, the lobes subequal, ovate-lanceolate, 4-8 mm long, acute to acuminate and glandular at apex; calyx to 2.2 cm in fruit, coriaceous, smooth, partially enclosing the fruit, calyx and pedicel often with raised lenticels at maturity. Corolla tube terete, curved and inflated slightly at apex, then constricted at throat, gradually widening from base, 2.5-4 cm long, 2 mm diameter at base, to 5 mm diameter at apex, glabrous; estivation quincuncial and imbricate, the limb spreading to 5.5 cm diameter, the lobes rounded, subequal, uppermost slightly larger, subtruncate to rounded at apex, overlapping at sides, narrowing lightly at base. Stamens four, in two pairs, included in upper portion of corolla tube; filaments ligulate, curved at apex, 2-3 mm long; anthers reniform, to 2 mm long. Ovary ovoid-conical, 2-3 mm long, glandular at base; style slender, curved and thickened at apex, 3-3.5 cm long; stigma weakly/briefly bifid, lobes equal, oval, 1-2 mm long, 8-10 mm in diameter. Fruit a capsule, globose to ovoid, 1.5-2 cm long, 1.2-1.8 cm wide, partially enclosed by accrescent calyx, slightly acute at apex with conspicuous scar where corolla tube was attached, medial septicidal suture present, not dehiscing along suture, dark green when fresh, light brown and lightly veined when dry, smooth, glabrous, pericarp thin walled, 1-2 mm thick, drying crustaceous, exocarp coriaceous, lenticelate. Seeds 10-20 per fruit, oblong-ellipsoid, 5-7 mm long, ca. 3 mm in diameter, dark reddish-brown with brilliant prismatic reflection, reticulate pitted, glabrous.

Habitat and ecology.

Known from central Peru in the Departments of Ucayali and Pasco where it is of extremely limited distribution but locally abundant at the type locality in the El Sira Communal Reserve. This understory species inhabits rocky slopes and ridge tops in cloud forests on the eastern slopes of the Cordillera El Sira, between 1100-1600 m, and has been found as a rare element in cloud forests on the northwestern slopes of the Cordillera Yanachaga, at ca. 2300 m.

Phenology.

Flowering in Brunfelsia cabiesesiana appears to be photomorphogenic in nature, associated with highest annual light intensities. Flowering observed in the El Sira populations is closely associated with the dry season, from August to October. Fruits appear to mature relatively slowly and are persistent, having been found green on the plant two or more months following anthesis.

Etymology.

The species epithet honors Dr. Fernando Cabieses Molina, noted neurosurgeon, ethno-pharmacologist, author and educator. Dr. Cabieses was cofounder of the Museo de la Nación of Peru and founding rector of the Universidad Científica del Sur. He served as director of the Peruvian Museum of Health Sciences and the Peruvian National Institute of Traditional Medicine. Dr. Cabieses had profound interest in tropical biodiversity -both its history and utilization- and he was a tireless supporter of biodiversity conservation efforts in Peru.

Conservation status.

This species is of extremely limited distribution (see Figure 1 ), although it appears to be locally abundant as evidenced by preliminary density studies along an elevational transect near the type locality, where 18 individuals were recorded in 2000 sq. m area. Three of these had reached maturity, as evidenced by stunted, persistent inflorescence branches (see Figure 2 ). This species appears to be extremely rare in the Cordillera Yanachaga, ca. 125 km SW from the type location and nearly 800 m higher in elevation.

Given the extremely limited known area of occupancy of Brunfelsia cabiesesiana , and the fragmented nature of the occurrence of the two known subpopulations in Pasco and Ucayali, we estimate the Pasco subpopulation to be critically endangered and the Ucayali population to be endangered, using International Union for the Conservation of Nature Red Book guidelines ( IUCN 2012). Both of the Pasco collections were located in fragmented forests near to roads. Given that anthropogenic activity in this region continues to expand, and that only two collections have ever been made, it is considered to face an extremely high risk of extinction in the wild. The Ucayali subpopulation, with the benefit of larger species densities, as well as a more favorable location inside a reserved zone, faces less threat of extinction.

Specimens examined.

PERU. Ucayali: Dist. Iparia, Reserva Comunal El Sira , 9°28'S, 74°34'W, 1550 m, 24 Oct 2007, J. G. Graham 4968 (F, MOL, NY) ; Pasco: Dist. Oxapampa, 10°37'S, 75°20'W, 2100 m, Villa Rica - Oxapampa, 4 Jan 1984, R. Foster et al. 7788 (F); Dist. Oxapampa, 10°30'S, 75°20'W, 4 Aug 2009, forest remnant at the edge of a road, R. Vasquez et al. 36203 (HOXA) .

Figures

Figure 1. Location of known specimens of Brunfelsia cabiesesiana.

Figure 2. Inflorescences of Brunfelsia cabiesesiana. Left, cauline corymbiform inflorescences showing limb of corolla at anthesis. Right, stem with bracteate inflorescence branches.

Figure 3. Fruits of Brunfelsia cabiesesiana. Below, dried, dehiscent capsules with seeds. Above left, developing fruits.

Figure 4. Estivation of Brunfelsia cabiesesiana. A calyces in bud. (day 1 - 3) B emerging flower. (day 4 - 5) C petals unfold (day 6 - 7).

Figure 5. Profile of a flower of Brunfelsia cabiesesiana at anthesis.

Figure 6. Two habit forms of Brunfelsia cabiesesiana found in the El Sira Mountains (drawing by JGG).