Cestrum talamancaense A.K.Monro, 2012

Monro, Alex K., 2012, Eight new species of Cestrum (Solanaceae) from Mesoamerica, PhytoKeys 8, pp. 49-82 : 70-73

Cestrum talamancaense A.K.Monro sp. nov. Fig. 9 A-D Fig. 10 A

Diagnosis.

Most similar to Cestrum laxum Benth. from which it can be distinguished by the absence of a minor leaf subtending axillary buds, flowers with shorter calyces that are pale pink or purple in colour.

Type.

Panama. Bocas del Toro: Cerro Fábrega, 09°04'81"N, 82°54'35"W (DDM), 3000 m, 10 Mar 2003, A. K. Monro, B. B. Klitgaard & J. DeGracia 4054 (holotype: PMA; isotypes: BM000811836, SCZ).

Description.

Lax shrub to 1-2 m. Leaf-bearing stems brown, the internodes 8-20 × 1-2 mm; young stems glabrous to sparsely pubescent, the hairs 0.5 mm, simple, erect, curved, not glandular. Axillary buds 0.5-1.5 mm, black, very dark brown, sparsely pubescent, not subtended by a minor leaf. Lamina 31-80 × 15-26 mm, length width ratio 2.6-3.1, ovate, lanceolate, or obovate, chartaceous tosubchartaceous or subcoriaceous, brown; the upper surface glabrous, primary and secondary, primary veins clearly visible to the naked eye, primary and secondary, primary raised; the lower surface glabrous, sparsely pubescent, the hairs 0.25 mm, simple, erect, curved, apparently glandular, orange-brown; primary to quarternary, primary to tertiary veins clearly visible to the naked eye, primary veins raised, veinlets not visible, secondary veins 5-8 pairs, 45-60° to the midrib, weakly curved; base decurrent, asymmetrical, decurrent-cuneate; margin irregularly entire; apex acute or subcuspidate; petioles borne on a woody or crescent shaped spur, 4-13 × 0.675-1.5 mm, dark brown, glabrous. Inflorescences 6 or 7 per herbarium sheet, axillary and indeterminate terminal, solitary, clustered towards the branch tips, 40-130 mm long, bearing 6-75 flowers in a panicle of 3-12 clusters, each cluster bearing 1 or 2 flowers; peduncle 22-25 × 0.675-0.750 mm, brown, moderatley pubescent, the hairs ca. 0.5 mm, branched, dendritic, eglandular; bracts 9-19 × 2-16 mm, leaf-like; bracteoles 1.5-2.5 mm, linear, glabrous. Flowers pedicellate, the pedicels 1.25-5.0 mm; calyx 2.5-4.0 × 2.0-2.25 mm, the outer surface glabrous, the lobes 5, 3, 0.5-1.0 mm long, erect; corolla pink to pale pink, 12-23 mm long, the tube 14-18.5 mm long, 3.0-4.5 mm in diameter at the mouth, 1.0-1.5 mm at the base, glabrous, the lobes 5, 2-3 mm long; stamens 5, the filaments 7.5-16.0 mm long, equal, adnate for 4.5-8.0 mm, with a reduced swelling-like to knee-like appendage present at insertion point, pubescent from insertion point to the base, the anthers 1.0-1.25 × 0.75-1.0 mm; style 7.5-18.0 mm, the stigma 0.75 × 1.25 mm. Infructescences not seen.

Etymology.

From the Talamanca mountains, the locality of all known collections of this species.

Distribution.

Cestrum talamancaense is known from three locations which span the entire range of the Talamanca Mountains from Chirripó, Costa Rica in the west to La Fortuna, Panama in the east. The altitude range for this species is believed to be 2000-3200 m. This and collection label data suggest that Cestrum talamancaense is restricted to oak forest and subparamo vegetation. Given the small number of collections this should be considered provisional. Using this altitude range and the location of the three known localities the Area of Occupancy is calculated to be 2,300 km2 ( Google Earth, accessed June 20, images from 2003, 2004, 2006).

Discussion.

Of the four collections of Cestrum talamancaense seen none had previously been identified to species. A comparison of the holotype and paratype material with type specimens from the herbaria listed in the Materials and methods section recovered Cestrum talamancaense as most similar to Cestrum laxum Benth. and Cestrum irazuense Kuntze. Cestrum laxum and Cestrum irazuense occupy a similar altitudinal range. Cestrum irazuense occupies an overlapping but broader geographical range whilst Cestrum laxum has a distinct and much broader geographical range being known from Mexico, Guatemala, El Salvador and Honduras. The species can be distinguished based on axillary bud, petiole and flower morphology as summarised in Tables 15 and 16 .

Conservation status.

Using IUCN criteria ( IUCN 2001) Cestrum talamancaense is considered Least Concern. Cestrum talamancaense has an Area of Occupancy of 2,300 km 2 (Criteria B2,>2000 km2) and meets a single subcriteria for criteria Ba (number of localities less than 5). In addition the whole of the range of this species is currently not fragmented and within protected areas both in Costa Rica and Panama. Should current attempts at illicit mining within the Area of Occupancy persist, however, the threat status may need to be revised to Near Threatened.

Paratypes.

COSTA RICA. San José: Parque Nacional Chirripó, Cuenca Térraba-Sierpe, Sabana, Chirripó, 09°25'12"N, 083°30'36"W, 3200 m, 6 Nov 1996, E. Alfaro, B. Gamboa & A. Picado 895 (BM, INB). PANAMA. Bocas del Toro: Parque Nacional La Amistad, Cerro Fabrega, 09°06'56"N, 82°52'15"W (DDM), 3200 m, 16 Mar 2003, B. B. Klitgaard, A. K. Monro & J. E. DeGracia 818 (BM, INB, MO, PMA, SCZ).); Chiriquí: Proyecto Fortuna, Valle de Hornito, 08°38'N, 082°13'W (DMS), ca. 2000 m, 13 Feb 1981, J. J. Him & I. O. Gordon 50 (PMA).

Figures

Figure 9. Cestrum talamancaense A. K. Monro A Flowering stem B Stamen C Longitudinal section through the corolla showing stamen arrangement D Flower. Drawn from A. K. Monro, B. B. Klitgaard & J. DeGracia 4054 (BM)

Figure 10. Cestrum talamancaense A. K. Monro A Inflorescence and flower. A. K. Monro, B. B. Klitgaard & J. DeGracia 4054 (Photo A. K. Monro 2003).