Cestrum knappiae A.K. Monro, 2012

Monro, Alex K., 2012, Eight new species of Cestrum (Solanaceae) from Mesoamerica, PhytoKeys 8, pp. 49-82 : 65-67

Cestrum knappiae A.K. Monro sp. nov. Fig. 7 A-D

Diagnosis.

Most similar to Cestrum acuminatum Francey from which it can be distinguished by the membranous to subchartaceous leaves, flowers with shorter calyces and the larger fruit.

Type.

Panama. Chiriquí /Bocas del Toro: along Continental Divide on trail in Zona Protectora Palo Seco, 08°47.1'N, 082°13'W (DMS), 1100-1300 m, 11 Aug 2000, S. Knapp & J. Mallet 9175 (holotype: BM000648809; isotypes: MEXU, MO-913564, PMA, SCZ).

Description.

Shrub or small tree to 1-7 m. Leaf-bearing stems yellow-brown, pale brown to tan, the internodes 8-25(33) × 0.75-5.0 mm; young stems glabrous. Axillary buds 0.75-6.0 mm, very dark green, green-brown, orange-brown, sparsely pubescent or glabrous, not subtended by a minor leaf. Lamina 27-210 × 8-43 mm, length width ratio 2.6-8.4, narrowly lanceolate, lanceolate, narrowly ovate or narrowly oblong, membranous to subchartaceous, occasionally chartaceous, green, dull green, yellow-green; the upper surface glabrous, primary, primary and secondary veins clearly visible to the naked eye, primary and secondary raised; the lower surface glabrous; primary, primary to tertiary or primary to secondary veins clearly visible to the naked eye, primary, primary and secondary veins raised, the veinlets visible or not, secondary veins 7-20(27) pairs, 75-90° to the midrib, weakly curved; base obtuse, acute, asymmetrical, acute / obtuse, obtuse / subcordate, acute / attenuate, acute / cuneate, obtuse / decurrent; margin entire, occasionally irregularly so; apex acuminate, subcaudate to caudate; petioles regular, 3-21 × 0.675-1.0 mm, dark green, brown or yellow-green, glabrous. Inflorescences 5-9 per herbarium sheet, axillary on apical portion of the stem, terminal, pendant, 55-150 mm long, bearing 3-10 flowers in a compact panicle of 2-7 clusters of flowers, each cluster bearing 1, 2 or 4 flowers; peduncle 15-70 × 0.50-0.75 mm, straw coloured or orange-brown, glabrous; bracts 16-60 × 3-14 mm, leaf-like; bracteoles 4.0-7.5(14.0) mm, linear, spathulate, narrowly ovate, 1 or 2 per flower, glabrous. Flowers pedicellate or subsessile, where pedicellate the pedicels 0.25-1.0 mm; calyx 2.0-2.5 × 1.75-2.675 mm, the outer surface glabrous, the lobes 5, 0.125-0.675 mm, erect; corolla pale green, white or yellow-green, 28-35 mm, the tube 20-28 mm long, 2.5-3.5 mm in diameter at the mouth, 0.75-1.0 mm at the base, glabrous, the lobes 5, 6-10.0 mm long; stamens 5, the filaments 21-25 mm long, equal, adnate for 17-21 mm, with a lobe-like appendage present at insertion point, pubescent at insertion point, the anthers 0.675-1.0 × 0.5-0.75 mm; style 21-26 mm, the stigma 0.375-0.750 × 0.674-2.0 mm. Infructescences 27-110 mm long, bearing 2-4 fruit; fruiting calyx 2.0-2.5 × 3.0-4.0 mm; fruit 7-14 × 7-12 mm, white when ripe. Seeds (2)6-10, 4.5-7.5 × 1.5-5.0 × 2.5-4.5 mm, the surface smooth.

Etymology.

This species is named after Sandra Knapp (1956-), Anglo-US botanist and Solanaceae specialist who collected the holotype and three of the paratype collections.

Distribution.

Tropical wet, premontane and montane forest from 1100 to 1600 m. Collection notes indicate that this species is known from primary or undisturbed forest. Existing collection localities suggest that Cestrum knappiae is restricted to an area of the Main Divide (river drainage between the Caribbean Sea and Atlantic Ocean) of the Talamanca Mountains ca. 270 km in extent that runs from Parque Nacional Tapantí in W in Costa Rica to the Fortuna Forest Reserve and Palo Seco Protected Areas in the E in Panama. The Extent of Occurrence is calculated to be 5,400 km2 ( Google Earth, accesssed June 2 2011, images 2001 to 2006).

Discussion.

Seven of the 15 collections of Cestrum knappiae examined had been previously determined as Cestrum fragile Francey. A comparison of the holotype and paratype material with type specimens from the herbaria listed in the Materials and methods section recovered Cestrum knappiae as most similar to Cestrum acuminatum D’Arcy, Cestrum fragile and Cestrum cristinae D.A.Soto. It can be distinguished from those species based on size, leaf, flower and fruit morphology as summarised in Tables 11 , 12 and 13 .

Conservation status.

Using IUCN criteria ( IUCN 2001) Cestrum knappiae is considered Near Threatened (NT). Cestrum knappiae meets criterion B1 (Extent of Occurrence <20,000 km2) and one subcriterion, a (number of localities <10). The full extent of the species’ Extent of Occurrence, however, is located within protected areas. There is considerable pressure for copper and gold mining within Costa Rica and Panama within the Extent of Occurrence which may present a threat of fragmentation or decline in the near to medium term future. If mining were to take place within this area then it is likely that Cestrum knappiae would be classified as Vulnerable.

Paratypes.

COSTA RICA. Cartago: Cantón de Paraíso, Tapantí Nacional Park, Río Reventazón water basin, Tapantí station, Arboles caidos trail, 09°44'53"N, 083°46'55"W (DMS), 1600 m, 10 Jan 1997, A. Rodríguez, S. Salas & A. Soto 1874 (BM). PANAMA. Bocas del Toro: Fortuna Dam area, Continental Divide, ridge trail to unnamed peak to E of Oleoducto road, 08°46'19"N, 082°11'51"W (DMS), 1200 m, 1 Aug 1984, H. W. Churchill 5861 (MO); 12 miles beyond Campamento Chami (12+12 mi from Río San Félix), 08°33'N, 081°48'W (DMS), 1400-1470 m, 20 Jun 1986, W. G. D'Arcy 16274 (MO); ca. 5 km ENE of Cerro Pate Macho near Finca Serrano, NE of Boquete, in forest along trail downhill from Finca Serrano, 08°50'24"N, 082°19'18"W (DMS), 1500 m, 12 Feb 1979, B. Hammel 6162 (MO); on gravel road branching N from main Fortuna Dam-Chiriquí Grande road, 1.1 miles from junction, 08°47'18"N, 082°14'00"W (DMS), 1200 m, 11 Mar 1985, G. McPherson 6801 (MO); along trail on divide separating Chiriqui and Bocas del Toro, 08°46'42"N, 082°12'48"W (DMS), 1150 m, 22 Oct 1985, G. McPherson 7203 (MO); along trail on divide separating Chiriqui and Bocas del Toro, 08°46'42"N, 082°12'48"W (DMS), 1150 m, 22 Oct 1985, G. McPherson 7205 (MO); N of Fortuna Dam on road to Chiriquí Grande, forested slopes along divide-trail, 08°46'36"N, 082°13'00"W (DMS), 1150 m, 18 Jan 1986, G. McPherson 8095 (MO); vicinity of Fortuna Dam. Trail along continental divide, 08°46'12"N, 082°09'00"W (DMS), 1300-1400 m, 6 Feb 1987, G. McPherson 10384 (MO); Bocas del Toro-Chiriquí:along Continental Divide on trail in Zona Protectora Palo Seco, 08°47'N, 082°13'W (DMS), 1100-1300 m, 11 Aug 2000, S. Knapp & J. Mallet 9182 (BM, MO, PMA, SCZ); along Continental Divide on trail in Zona Protectora Palo Seco, 08°47'N, 082°13'W (DMS), 1100-1300 m, 11 Aug 2000, S. Knapp & J. Mallet 9188 (BM, MO, PMA, SCZ); Chiriquí: Distrito de Guanaca, Cordillera Central, Trocha, 08°47'N, 082°14'W (DMS), ca. 1000 m, 27 Aug 1993, M. Correa, E. Montenegro, H. Navarrete & E. Hidalgo 9836 (PMA); ridges above and W of Quebrada Aleman, trail to town of Fortuna, 08°45'N, 082°13'W (DMS), 1200-1500 m, S. Knapp & J. Mallet 9224 (BM, PMA); Cordillera Central, 7 Dec 1996, E. Montenegro 1595 (BM); Fortuna, Trocha Cordillera Central close to the Continental Divide, 28 Oct 1997, E. Montenegro 1799 (INB, BM).

Figures

Figure 7. Cestrum knappiae A. K. Monro A Flowering stem B Style C Longitudinal section through the corolla showing stamen arrangement D Flower. Drawn from S. Knapp & J. Mallet 9175 (BM).