Solanum pacificum, Tepe,

Tepe, EJ & Bohs, L, 2011, A revision of Solanum section Herpystichum, Systematic Botany 36 (4), pp. 1068-1087 : 1081-1082

7. SOLANUM PACIFICUM Tepe,

J. Bot. Res. Inst. Texas 3: 512. 2009.

—TYPE: ECUADOR. Los Ríos: Centro Científico Río Palenque, in secondary forest , 215 m, 5 Feb 2009 (fl, fr), E. J. Tepe et al. 2696 (holotype: QCNE!; isotypes: BM!, MO!, NY–NY01163476!, QCA!, UT!).

Herbaceous vine, climbing secondary vegetation in gaps. Stems slender, weakly herbaceous, glabrous; fertile branch tips pendent. Sympodial units plurifoliate. Leaves simple, the blades 14–19 × 4.5–8 cm, 2–3 times as long as wide, lanceolate to ovate, membranaceous to thinly chartaceous, moderately to densely sand-punctate, glabrous adaxially and abaxially; venation pinnate, with 4–7 pairsofsecondaryveins, these densely sand-punctate; base rounded to obtuse, more or less symmetrical; margins entire; apex acuminate; petioles 1– 1.5 cm, densely sand-punctate, glabrous. Internodes 1.5–7 cm. Inflorescences 4–10 cmlong, slender, unbranched, extraaxillary, with 17–58 flowers (scars), the axes glabrous, slender; peduncle 2–4.5 cm; rachis ca. 6 cm; pedicels 8–10 mm in flower, slender, 15–20 mm in fruit, enlarged apically, glabrous, spaced nearly contiguously to 12 mm apart. Calyx 1–1.2 mm long, glabrous to minutely and sparsely ciliate along margins, the tube 0.5–0.7 mm long, the lobes 0.5–0.6 × 0.8–1 mm, rounded, rounded to weakly acuminate at tips; fruiting calyx somewhat accrescent, the lobes 0.6–0.8 × ca. 1 mm. Corolla 0.8–1 cm in diameter, ca. 5 mm long, stellate, membranous, green to white near the margins of the petals, the lobes 4–5 × 1.2–2.5 mm, ovate, reflexed at maturity, acute at apices, glabrous adaxially and abaxially, the margins ciliate. Stamens subequal, with filaments ca. 0.8 mm long, glabrous; anthers 1.5–2 × 0.7–1.2 mm. Ovary glabrous; style 4–4.5 × 0.1–0.2 mm, glabrous, slightly clavate; stigma truncate. Fruit (immature) ca. 0.9 × 0.6 cm, ovoid, somewhat flattened, pointed at apex, green, glabrous. Seeds unknown. Figure 1J–K .

Habitat and Distribution— Solanum pacificum occurs in primary and secondary rainforest habitats in the Pacific lowlands of Ecuador; 50–380 m in elevation ( Fig. 8 ).

Phenology— Flowering specimens have been collected from Feb.–Aug.; the type collection, collected in Feb., is the only fruiting specimen seen. It is likely that fruiting is more frequent than the collection record indicates.

Conservation Status— According to the IUCN red list categories ( IUCN 2010), S. pacificum is classified as B1a+3iii (critically endangered) and D2 (vulnerable because of restricted area of occupancy). This species is restricted to lowland rainforest habitats of western Ecuador. This habitat type has suffered extreme degradation, and has been reduced from an estimated 32,000 km 2 to ca. 1,500 km 2 ( Dodson and Gentry 1991). The six known collections of S. pacificum are from a small portion of this area, and because of the extensive habitat destruction, it is possible that this species survives only within the 0.87 km 2 Centro Científico Río Palenque.

Etymology— Solanum pacificum is named after the Pacific lowlands of Ecuador where it is endemic, and for María Paz Moreno, the first author’s wife and frequent field companion. “Pax,” Latin for peace, is the root of both “Pacific” and “Paz.”

Notes— Solanum pacificum is a climbing species recognizable by its completely glabrous vegetative parts; slender, weakly herbaceous stems; small, greenish flowers; and large, thin leaves. The leaves of S. pacificum are deep purplish-green above with whitish veins, and are weakly to intensely purple below. The upper surfaces of fresh leaves have a distinctly velvety luster.

Within sect. Herpystichum , this species is most similar to S. dolichorhachis , but differs in having leaves with ± symmetrical vs. distinctly oblique leaf bases and green, herbaceous vs. tan, woody stems. It can be distinguished from other climbing species by the texture, shape, and size of the leaves. Solanum pacificum is also similar to the sympatric S. leptorhachis Bitter [sect. Geminata (G. Don) Walp .] in the size and shape of the leaves, the long, slender inflorescences, and small, greenishwhite, stellate flowers; however, S. leptorhachis is an upright, woody shrub with unifoliate sympodial units on flowering stems and geminate leaves at nonflowering nodes. In contract, S. pacificum has plurifoliate sympodial units and always has only one leaf per node (i.e. not geminate).

Additional Specimens Examined— ECUADOR. Junction of the provinces Bolivar, Cañar, Chimborazo, and Guayas: Foothills of the western cordillera near the village of Bucay, 1,000 –1,250 ft, 8–15 Jun 1945 (st), W. H. Camp E-3782 ( MO). Los Ríos: Cantón Quevedo, Centro Científico Río Palenque, along road between Santo Domingo de los Colorados and Quevedo at km 47, 1.7 km Sof Patricia Pilar, 0°35’S 79°21’W, 220 m, 9 Apr 1992 (st), T. B. Croat 73807 ( MO); Río Palenque Biological Station, km 56 Rd. Quevedo-Santo Domingo, 150–220 m, 26 Oct 1974 (st), C. H. Dodson 5663 ( SEL); Río Palenque Biological Station, km 56 Rd. Quevedo-Santo Domingo, 150–220 m, 7 Aug 1975 (fl), C. H. Dodson 5933 (AAU, MO, QCA, SEL); Río Palenque Field Station, half way between Quevedo and Santo Domingo de los Colorados, 200 m, 22 Feb 1974 (fl), A. Gentry 10109 ( MO).

Figures

FIG.1. Flowers fruits, and habit of Solanum sect. Herpystichum: A. Solanum limoncochaense, habit, flower, and bud. B. S. limoncochaense fruit in situ and C. in cross section (E. J. Tepe & S. Stern 2627, QCNE). D. S. trifolium flower and leaf (E. J. Tepe & S. Stern 2682, QCNE). E. S. phaseoloides habit, flower, and leaf (photo by W. H. Haber). F. S. crassinervium habit (E. J. Tepe & S. Stern 2729, QCNE), and G. flowers (S. Stern & E. J. Tepe 400, QCNE). H. S. evolvulifolium habit and flower, and I. fruit (immature) (E. J. Tepe & S. Stern 2671, QCNE). J. S. pacificum inflorescence with flowers, buds, and fruit (immature), and K. habit (E. J. Tepe et al. 2696, QCNE). L. S. loxophyllum habit, note adventitious roots at nodes, and M. older stem with inflorescences, note figure eightshaped stem (E. J. Tepe & S. Stern 2726, QCNE). Inflorescences emerge from the cleft between the two lobes of the stem.

FIG.8. Distribution of Solanum pacificum and S. pentaphyllum.